AvaSoft 8 Manual
ID:020379
Table of Content
Table of Content ....................................................................................................... 1
1
AvaSoft installation.............................................................................................. 5
1.1
Installation program ...................................................................................... 5
1.2
Launching the software .................................................................................. 7
2
Quick Start: Measuring and saving a spectrum ............................................................. 8
3
Differences from earlier versions of AvaSoft ............................................................... 9
4
The AvaSoft windows ......................................................................................... 10
4.1
Main window .............................................................................................. 10
4.1.1
‘File’ tab, ‘New Experiment’ menu option ................................................... 10
4.1.2
‘File’ tab, ‘Load Experiment’ menu option ................................................... 11
4.1.3
‘File’ tab, ‘Save Experiment’ menu option ................................................... 11
4.1.4
‘File’ tab, ‘Convert from AvaSoft 7 to AvaSoft 8’ menu option ........................... 11
4.1.5
‘File’ tab, ‘Convert File To ASCII/Excel/JCAMP/GRAMS’ menu option .................. 12
4.1.6
‘File’ tab, ‘Tools for Plug In accessories’ menu option ..................................... 13
4.1.7
‘File’ tab, ‘Select Spectrometers’ menu option ............................................. 13
4.1.8
‘File’ tab, ‘About’ Button ........................................................................ 14
4.1.9
‘File’ tab, ‘Exit’ Button .......................................................................... 14
4.1.10
‘Home’ ribbon tab, ‘Start/Stop’ Button ....................................................... 14
4.1.11
‘Home’ ribbon tab, ‘Single’ Button ............................................................ 15
4.1.12
‘Home’ ribbon tab, ‘Dark’ Button .............................................................. 15
4.1.13
‘Home’ ribbon tab, ‘Reference’ Button ....................................................... 15
4.1.14
‘Home’ ribbon tab, ‘Auto Configure’ Button ................................................. 15
4.1.15
‘Home’ ribbon tab, ‘Options’ Button .......................................................... 15
4.1.16
‘Home’ ribbon tab, ‘Sync’ Button .............................................................. 19
4.1.17
‘Home’ ribbon tab, ‘Tools’ Button ............................................................. 20
4.1.18
‘Home’ ribbon tab, Application Buttons ...................................................... 21
4.1.19
‘View’ ribbon tab, ‘Dock All’ Button ........................................................... 22
4.1.20
‘View’ ribbon tab, ‘Tile in Grid’ Button ....................................................... 22
4.1.21
‘View’ ribbon tab, ‘Tile Vertically’ Button ................................................... 22
4.1.22
‘View’ ribbon tab, ‘Tile Horizontally’ Button ................................................ 22
4.1.23
‘View’ ribbon tab, ‘Set Panel Indicators’ Button ............................................ 22
4.2
Experiment Window ..................................................................................... 22
4.3
Spectrometer Window .................................................................................. 22
4.3.1
Friendly name ‘Spectrometer Settings’ dialog ............................................... 22
4.3.2
Collapse / Expand button ........................................................................ 22
4.3.3
‘Spectrometer Settings’ Button ................................................................. 22
4.3.4
‘Save Dark Spectrum’ Button .................................................................... 33
4.3.5
‘Save Reference Spectrum’ Button ............................................................. 33
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4.3.6
‘Autoconfigure’ Button ........................................................................... 33
4.3.7
‘Activate / Deactivate’ Button ................................................................. 33
4.3.8
‘Progress Bar’ Panel Indicator................................................................... 33
4.3.9
‘Integration Time [ms]’ Panel Indicator ....................................................... 33
4.3.10
‘Averaging’ Panel Indicator ...................................................................... 33
4.3.11
‘Saturated’ Panel Indicator ...................................................................... 34
4.3.12
‘Custom Reflectance’ Panel Indicator ......................................................... 34
4.3.13
‘Measurements’ Panel Indicator ................................................................ 34
4.3.14
‘Detector Temp and Setpoint’ Panel Indicator............................................... 34
4.4
Spectrum Application Window ........................................................................ 34
4.4.1
‘Home’ ribbon tab, ‘Open’ Button ............................................................. 34
4.4.2
‘Home’ ribbon tab, ‘Save’ Button .............................................................. 34
4.4.3
‘Home’ ribbon tab, ‘Legend’ Button ........................................................... 34
4.4.4
‘Home’ ribbon tab, ‘Scope Mode’ Button ..................................................... 34
4.4.5
‘Home’ ribbon tab, ‘Scope minus Dark Mode’ Button ...................................... 34
4.4.6
‘Home’ ribbon tab, ‘Absorbance Mode’ Button .............................................. 35
4.4.7
‘Home’ ribbon tab, ‘Transmittance Mode’ Button .......................................... 35
4.4.8
‘Home’ ribbon tab, ‘Reflectance Mode’ Button ............................................. 35
4.4.9
‘Home’ ribbon tab, ‘Absolute Irradiance Mode’ Button .................................... 35
4.4.10
‘Home’ ribbon tab, ‘Relative Irradiance Mode’ Button ..................................... 35
4.4.11
‘Home’ ribbon tab, ‘Auto Scale Y-axis’ Button .............................................. 35
4.4.12
‘Home’ ribbon tab, ‘Graphic Reset’ Button .................................................. 35
4.4.13
‘Home’ ribbon tab, ‘Preset Scale’ Button .................................................... 36
4.4.14
‘Home’ ribbon tab, ‘Grid’ Checkbox ........................................................... 36
4.4.15
‘Home’ ribbon tab, ‘Visible Spectrum’ Checkbox ........................................... 36
4.4.16
‘Home’ ribbon tab, ‘Logarithmic’ Checkbox ................................................. 36
4.4.17
‘Home’ ribbon tab, ‘Photon Density’ Checkbox ............................................. 36
4.4.18
‘Home’ ribbon tab, ‘Splining On’ Button ...................................................... 36
4.4.19
‘Home’ ribbon tab, ‘Splining Off’ Button ..................................................... 37
4.4.20
‘File’ ribbon tab, ‘Open Spectral Data’ Button .............................................. 37
4.4.21
‘File’ ribbon tab, ‘Import V7 Spectral Data’ Button ........................................ 37
4.4.22
‘File’ ribbon tab, ‘Save Spectral Data’ Button ............................................... 37
4.4.23
‘File’ ribbon tab, ‘Export Spectral Data’ Button ............................................ 37
4.4.24
‘File’ ribbon tab, ‘Copy Graph’ Button ........................................................ 38
4.4.25
‘File’ ribbon tab, ‘Save Graph As’ Button .................................................... 38
4.4.26
‘File’ ribbon tab, ‘Print Graph’ Button ........................................................ 38
4.4.27
‘File’ ribbon tab, ‘Live Excel Output’ Button ................................................ 38
4.4.28
‘File’ ribbon tab, ‘Save Live Output Periodically’ Button .................................. 38
4.4.29
‘Tools’ ribbon tab, ‘New Integral’ Button .................................................... 38
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4.4.30
‘Tools’ ribbon tab, ‘Magnify Tool On’ Button ................................................ 38
4.4.31
‘Tools’ ribbon tab, ‘Magnify Tool Off’ Button ................................................ 39
4.4.32
‘Tools’ ribbon tab, ‘Assign Cursor’ Button .................................................... 39
4.4.33
‘Tools’ ribbon tab, Cursor Wavelength Edit Box ............................................. 39
4.4.34
‘Tools’ ribbon tab, Cursor Tool ‘OK’ Button .................................................. 39
4.4.35
‘Tools’ ribbon tab, ‘Spectrum Chart Name’ Button ......................................... 39
4.4.36
‘Tools’ ribbon tab, ‘Base Line On’ Button .................................................... 39
4.4.37
‘Tools’ ribbon tab, ‘Base Line Off’ Button .................................................... 39
4.4.38
‘Tools’ ribbon tab, ‘Show Legend’ Checkbox ................................................ 39
4.4.39
Status bar ........................................................................................... 39
4.4.40
Peak submenu ...................................................................................... 39
4.4.41
Find peaks or valleys by CTRL or SHIFT + right mouse button click ...................... 40
4.4.42
Spectrum Info window ............................................................................ 41
4.5
Spectrum3D window .................................................................................... 42
4.5.1
‘View’ ribbon tab, ‘Channel’ Button ........................................................... 44
4.5.2
‘View’ ribbon tab, Measure Mode selection .................................................. 44
4.5.3
‘View’ ribbon tab, Adjust View selection ..................................................... 44
4.5.4
‘View’ ribbon tab, Change Graph Scale ....................................................... 44
4.5.5
‘File’ ribbon tab, ‘Open Separate Spectra Files’ Button ................................... 44
4.5.6
‘File’ ribbon tab, ‘Save Scans to Separate Files’ Button ................................... 44
4.5.7
‘File’ ribbon tab, ‘Open Single File Data (*.str)’ Button ................................... 44
4.5.8
‘File’ ribbon tab, ‘Save Single File Data (*.str)’ Button .................................... 44
4.5.9
‘File’ ribbon tab, ‘Export to Excel’ Button ................................................... 44
4.5.10
‘File’ ribbon tab, ‘Export to Ascii’ Button .................................................... 44
4.5.11
‘File’ ribbon tab, ‘Save Graphs’ Button ....................................................... 44
4.5.12
‘File’ ribbon tab, ‘Export 3D Graph’ Button .................................................. 45
4.5.13
‘Settings’ ribbon tab, ‘Input File Sort Order’ Selection .................................... 45
4.5.14
‘Settings’ ribbon tab, ‘Chart Accuracy’ Selection ........................................... 45
4.6
Time Series ............................................................................................... 45
4.6.1
‘Function’ ribbon tab, ‘Start / Stop’ Button ................................................. 45
4.6.2
‘Function’ ribbon tab, ‘New Function’ Button ............................................... 45
4.6.3
‘Function’ ribbon tab, ‘Function’ Selection .................................................. 45
4.6.4
‘Function’ ribbon tab, ‘Device’ Field .......................................................... 45
4.6.5
‘Function Entry’ ................................................................................... 45
4.6.6
‘Graph’ ribbon tab, ‘Open’ Button ............................................................. 53
4.6.7
‘Graph’ ribbon tab, ‘Export’ Button ........................................................... 53
4.6.8
‘Graph’ ribbon tab, ‘Copy’ Button ............................................................. 53
4.6.9
‘Graph’ ribbon tab, ‘Print’ Button ............................................................. 53
4.7
Chemometry .............................................................................................. 53
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4.7.1
Quick Start: How to make concentration measurements with the Chemometry
application ...................................................................................................... 54
4.7.2
Setup and Calibration form ...................................................................... 55
4.7.3
Measurement form ................................................................................ 57
4.8
Color ....................................................................................................... 58
4.8.1
Color of an Object - Background ............................................................... 58
4.8.2
‘Home’ ribbon tab, ‘Channel’ Button .......................................................... 59
4.8.3
‘Home’ ribbon tab, ‘Edit’ Button ............................................................... 59
4.8.4
‘Home’ ribbon tab, ‘Start/Stop’ Button ....................................................... 63
4.8.5
‘Home’ ribbon tab, ‘Save Reference Color’ Button ......................................... 64
4.8.6
‘Home’ ribbon tab, ‘Pick Reference Color’ Button .......................................... 65
4.8.7
‘Home’ ribbon tab, ‘Save Col. Values’ Button ............................................... 65
4.9
Irradiance ................................................................................................. 65
4.9.1
Background ......................................................................................... 66
4.9.2
Quick Start .......................................................................................... 73
4.9.3
Load Intensity Calibration ....................................................................... 74
4.9.4
Perform Intensity Calibration ................................................................... 75
4.9.5
Irradiance Application Window ................................................................. 81
4.10
Thin Film .................................................................................................. 87
4.10.1
Film Thickness Primer ............................................................................ 87
4.10.2
Quick Start: Measuring and saving a Reflectance spectrum and a Film Thickness .... 88
4.10.3
Thin Film Application Window .................................................................. 89
Appendix A: USB driver installation .............................................................................. 98
Appendix B: Error Messages ...................................................................................... 100
Appendix C: Using the Ethernet spectrometer ................................................................ 101
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1
AvaSoft installation
Before you connect the AvaSpec spectrometer to the USB port of your computer, you need to install
the AvaSoft software first.
AVASOFT version 8 is a 32-bit application that can be installed under the following operating
systems:
- 32 bit XP/Vista/Windows 7/Windows 8/Windows 10
- 64 bit XP/Vista/Windows 7/Windows 8/Windows 10
1.1 Installation program
With each new spectrometer system, an AVANTES PRODUCT CD-ROM is included. One of the options
in the main menu which is shown after the CD-ROM is inserted in the CD-ROM drive, is to install
AvaSoft software. After selecting this option, a submenu is displayed in which the spectrometer
configuration can be selected.
AvaSoft 8 can be installed for any of the AvaSpec-USB2 and AvaSpec-EVO group of spectrometers:
Installation Dialogs
The setup program will check the system configuration of the computer. If no problems are
detected, the first dialog is the “Welcome” dialog with some general information.
In the next dialog, the destination directory for the AvaSoft software can be changed. The default
destination directory is C:\Program Files (x86)\AvaSoft8. If you want to install the software to a
different directory, click the Browse button, select a new directory and click OK. If the specified
directory does not exist, it will be created.
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After this, the “Start Installation” dialog is shown. After clicking the “Next” button, the installation
program starts installing files.
During the installation, the install program will check if the WinUSB driver has been installed on the
PC. In some earlier AvaSoft versions (and only on 32bit versions of Windows), an Avantes kernel USB
driver was installed for AS5216 spectrometers.
The install program will launch the Device Driver Installation Wizard to install the WinUSB driver.
The driver package has been signed by Avantes. Please select the ‘Install’ button to install the
WinUSB driver.
The last dialog in the Device Driver Installation Wizard displays whether the WinUSB driver has been
installed correctly.
If you experience problems here, please refer to Appendix A, which describes some special cases.
After all files have been installed, the “Installation Complete” dialog shows up. Click Finish.
Connecting the hardware
Connect the USB connector to a USB port on your computer with the supplied USB cable. Windows
XP will display the “Found New Hardware” dialog. Select the (default) option to install the software
automatically, and click next. After the Hardware Wizard has completed, the following dialog is
displayed under Windows XP:
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Click Finish to complete the installation.
For Windows XP, please note that if the spectrometer is connected to another USB port to which it
has not been connected before, the “Found New Hardware Wizard” will need to install the software
for this port as well. For this reason, with a multichannel AvaSpec-USB2 spectrometer system this
Wizard will run as many times as the number of spectrometers attached. This happens because
inside the housing, the USB ports for each spectrometer channel are connected to a USB-Hub.
Windows Vista and up will install the driver silently, without displaying the “Found New Hardware
Wizard” dialogs.
1.2 Launching the software
AvaSoft can be started from the Windows Start Menu. Under ‘Start’, ‘All Programs’, a group
“AVANTES Software” has been added, which has an entry for the AvaSoft 8 program and an entry for
the AvaSoft 8 helpfile.
There will also be an AvaSoft 8 icon on the desktop that you can click.
After starting the AvaSoft 8 software, a welcome window will be displayed that will show the
spectrometers that are connected.
The AvaSoft 8 windows will be displayed next. Refer to section 4 for a description of the different
windows. A “Quick Start” can be found in section 1, directly below, if you want to start measuring
immediately. Depending on the AvaSoft version (Basic or Full) and the extra add-on modules that
were ordered for your spectrometer, more applications are available in AvaSoft 8, which are
described in section 4.5 to 4.9.
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2
Quick Start: Measuring and saving a spectrum
1. After starting AvaSoft, the Start button in the upper left corner of the screen needs to be
clicked to start measuring.
2. Connect a fiber or probe to the light source and to the spectrometer input port(s) and set
up the experiment for taking a reference spectrum.
3. Optimal smoothing is preset and stored on board in the EEPROM.
4. Now turn on the light source. Usually some sort of spectrum may be seen on the screen, but
it is possible that too much or too little light reaches the spectrometer at the present data
collection settings. Too much light means that, over a certain wavelength range, the signal
is saturated shown as a straight line at the maximum counts and the appearance of the label
“saturated” in the spectrometer window of the channel. This can usually be solved by a
shorter integration time. The integration time can be changed in the spectrometer window
(by pressing the cogwheel icon, by directly changing the ms value, or by pressing the Autoconfigure Integration time button. Try to adjust the integration time, such that the
maximum count over the wavelength range is around 90% of the full ADC scale (59000
counts for a 16bit ADC). When at minimum integration time the signal is still too high, an
attenuator, a neutral density filter or fibers with a smaller diameter may be used. When not
enough light reaches the spectrometer, likewise a longer integration time should be
entered.
5. When a good spectrum is displayed, turn off the light source.
6. Now save the Dark data. This can be done by clicking the dark bulb icon in the spectrometer
window, or the one on the left top of the screen with the mouse. Always use Save Dark after
the integration time has been changed.
7. Turn on the light source again. Save the present spectrum as a reference by clicking the
bright bulb icon (next to the dark one). Always use Save Reference after the integration
time has been changed. Now the measure mode can be changed to e.g. Absorbance (A
button) or Transmittance (T button). To have a better look at the amplitude versus
wavelength, the Assign Cursor button can be clicked in the Tools menu. A vertical line is
then displayed in the graph. If the mouse cursor is placed nearby this line, the shape of the
mouse cursor changes from an arrow to a ‘splitter’ shape. If this shape is displayed, the left
mouse button can be used to drag (keep left mouse button down) the line with the mouse
towards a new position. Moving this line shows the corresponding values of wavelength and
amplitude in the status line of the screen. By clicking the stop button, the data acquisition
is stopped and the last acquired spectrum is shown in static mode. The data acquisition can
be started again by clicking the same button, which now displays ‘Start’.
8. To save the spectrum (in the mode chosen before), choose ‘File’-‘Save’ from the menu.
9. To improve the Signal/Noise ratio, a number of spectra may be averaged. To do this, the
value in the spectrometer window (below the integration time) can be increased. The new
value will take effect when you press the ‘Set’ button.
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3
Differences from earlier versions of AvaSoft
AvaSoft8 represents a major change when comparing it to AvaSoft7. The software was completely
rewritten and made much more modular, resulting in better stability and maintainability, essential
for a program of this complexity.
-
-
The look and feel of the software was modernized, using Office like ribbons and buttons.
You can open new windows at will and view them either docked or as separate windows.
This means you can now use bigger or multiple screens much more effectively.
The limit of 8 spectrometers was removed.
The limit of 8 time series was removed.
Separation of measurement screens and spectrometer setup screens.
You can now open more windows for the same channel, viewing multiple measurement
modes at the same time.
The number of files saved is substantially lowered. Multiple channels can be saved in a
single file and StoreToRam/3D sessions are saved in a single file.
Better management of experiments and of the data file directories on your PC.
Several measurement modes were added, such as a separate Scope minus Dark mode,
separate Reflectance and Transmittance modes and separate Absolute and Relative
Irradiance modes.
A logarithmic scale was added.
A visible color spectrum scale was added.
The release notes for AvaSoft8 versions can be found by clicking the
questionmark button in the upper right corner, followed by selecting the
Release Notes menu option.
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4
The AvaSoft windows
AvaSoft 8 has an multiple document interface structure. The main program consists of the top
ribbon, the left side Experiment window and the left side Spectrometer windows.
The largest part of the screen consists of the client windows, a variable number of which can be
opened by the user. With these client windows, the different applications are opened. Some of
these applications are always present, like the Spectrum, Spectrum3D and TimeSeries applications.
Others, like the Chemometry, Color, or Irradiance applications, are installed later, as a plug-in
application.
The client windows can be undocked from the main window and positioned on other parts of the
screen, even outside of the main window.
4.1 Main window
4.1.1
‘File’ tab, ‘New Experiment’ menu option
Lets you start a new experiment.
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4.1.2
‘File’ tab, ‘Load Experiment’ menu option
Loads the setup data for a session.
Select the session you want and click ‘Open’.
You can add another session file to the list by clicking the ‘Add Experiment’ button and selecting
the corresponding file on disk.
4.1.3
‘File’ tab, ‘Save Experiment’ menu option
Saves the setup data for the current session.
The current experiment setup will be saved to disk. Enter a session name, the directory on disk
where the file will be saved and a description. Next press the ‘Save’ button.
4.1.4
‘File’ tab, ‘Convert from AvaSoft 7 to AvaSoft 8’ menu option
This selection starts a batch converter for AvaSoft 7 files. Note that you can also open AvaSoft 7
files in the ‘Spectrum’ application, described below in section 4.4.
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4.1.5
‘File’ tab, ‘Convert File To ASCII/Excel/JCAMP/GRAMS’ menu option
This option allows you to convert files that were saved earlier to different formats.
If you select ‘To ASCII’, you can first select whether you want to convert separately selected files,
or all files in a selected subdirectory.
Next, a window shows all files in the current measure mode. In the example below, the measure
mode is ‘Scope Mode’, so the extension of the earlier saved spectra is *.RAW8.
To select graphic files that were saved in another measure mode, e.g. absorbance, click
the Mode display, and pick the desired measure mode.
behind
To select graphic files from another folder or drive, click
behind the current folder name.
Selecting multiple filenames can be realized by using the CTRL or SHIFT key in combination with the
mouse.
If the CTRL key is pressed, all the files that are clicked by the mouse will be selected for
conversion. If the SHIFT key is pressed, all the files in between two clicked files will be selected for
conversion.
Select the name of the file(s) to be converted to ASCII and click the Open button. To leave this
dialog without converting files, click the Cancel button.
Extensions of
- RAW8
- RWD8
- ABS8
- TRM8
- RFL8
- IRR8
- RIR8
binary files:
Scope Mode
Scope Corrected for Dark Mode
Absorbance Mode
Transmittance Mode
Reflectance Mode
Absolute Irradiance Mode
Relative Irradiance Mode
Two or more channels in a merge group can be stored in file with an extension that adds an ‘x’
character. For example the extension RAW8x is used for a merge group in scope mode. Please note
that only the separate spectra are stored in this file, and not a merged spectrum. A continuous
merged spectrum can afterwards be obtained from a RAW8x file, and saved e.g. in ASCII format.
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All converted text files start with a header with information for the graphic file that has been
converted. The header shows:
- the comment line
- the integration time
- the number of scans that has been averaged
- the number of pixels used for smoothing
- the serial number of the spectrometer that was used to save the data
The data in a converted scope mode file is given in four columns. The first column gives the
wavelength in nanometers, the second one the scope data, the third the dark data and the fourth
the reference data.
The data in the converted files for all other modes is presented in five columns. The fifth column
gives the calculated value that the mode offers.
4.1.6
‘File’ tab, ‘Tools for Plug In accessories’ menu option
This selection allows you to install available plug-in options to the program.
4.1.7
‘File’ tab, ‘Select Spectrometers’ menu option
This selection opens a form that lets you select Ethernet spectrometers. The top box lists all
spectrometers connected by USB. The bottom box will list all spectrometers connected by Ethernet,
after pressing the ‘Update’ button. Depending on your network, you might need to press ‘Update’
several times. The check box in front of each Ethernet spectrometer controls whether the
spectrometer will be opened in AvaSoft. You can check each checkbox individually, or use the
‘Select All’ and ‘Deselect All’ buttons to select or deselect all available spectrometers at once.
The ‘Apply’ button will save your settings, the ‘Cancel’ button lets you leave without changes.
See also section 4.1.15.1 about including spectrometers with Ethernet communication in AvaSoft
and Appendix C for general background information about Ethernet communication.
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4.1.8
‘File’ tab, ‘About’ Button
This brings up the About Box which shows some information about the AvaSoft version that is being
used, the serial numbers of the spectrometers that are connected, detector types, firmware and
FPGA versions, the AvaSpec DLL version, the Windows version of the computer and the available
memory.
4.1.9
‘File’ tab, ‘Exit’ Button
Closes AvaSoft
4.1.10
‘Home’ ribbon tab, ‘Start/Stop’ Button
The Start/Stop button can be used to display data real-time or to take a snapshot. It applies to all
spectrometers that are connected.
Pull down menu:
- Single measurement
- Continuous
- Store to Ram
- L.I.B.S.
- Logging Enabled
In ‘Single’ mode, a single measurement is made on all spectrometers.
In ‘Continuous’ mode, a series of measurements is performed. A new measurement is started
automatically after the previous one is finished. This is repeated until the ‘Stop’ button is pushed.
In ‘StoreToRam’ mode, a fixed number of measurements is made, without the overhead of USB
communications. The number to scan can be set in the spectrometer settings. The scans are stored
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in the internal memory of the AvaSpec, and the results are only sent to the computer after the last
measurement has been made.
‘L.I.B.S.’ mode is a special mode of the program that has to be enabled in the ‘Options’ first.
‘Logging Enabled’ is used when logging all scans to disk. In ‘Options’, ‘Save Spectra Periodically’,
you must select the number of scans and optional time delays. You can also select here whether you
want the scans to be saved as separate files, or as a single StoreToRam format file.
4.1.11
‘Home’ ribbon tab, ‘Single’ Button
This is equivalent to the ‘Single’ measurement option of the Start/Stop button.
4.1.12
‘Home’ ribbon tab, ‘Dark’ Button
This will save the dark data for all spectrometers. The color of the corresponding Save Dark
icons in the spectrometer windows will change to green.
4.1.13
‘Home’ ribbon tab, ‘Reference’ Button
This will save the reference data for all spectrometers. The color of the corresponding Save
Reference icons in the spectrometer windows will change to green.
4.1.14
‘Home’ ribbon tab, ‘Auto Configure’ Button
This will Auto Configure the integration time for all spectrometers. Depending on the
maximum counts in the last scan, the integration time will be increased/decreased
automatically until a scope signal of about 90% of the full scale is measured. The number of
averages is set to a target cycle time of 500 ms, with a minimum value of 2 and a maximum
value of 100 averages.
4.1.15
‘Home’ ribbon tab, ‘Options’ Button
4.1.15.1
-
-
-
Save Options
Auto Increment Filename:
Here you can set the way the filename is patterned when using filenames that are auto
incremented when you save multiple scans. You can base the name on your experiment, on
the name of the window (plugin caption), or you can define it yourself. It is also possible to
add a date stamp or a time stamp to the name.
Suppress Save Comments Dialog:
You can select this option to prevent having to enter a comment for every saved scan, when
you want to save many files.
Suppress ASCII Header:
You can select this header when you want to save readings without header, e.g. when you
want to import them into another application.
The wavelength values of the detectors supported by AvaSoft are not evenly spaced (or
equidistant). For highest accuracy, our output files reflect this, and this behavior is fully supported
by the respective SPC and DX output file standards,
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Some third party programs, however, cannot handle non-evenly spaced wavelength values. You may
need to use the following options with these programs:
-
-
-
Save to ASCII in Equidistant Format:
Normally, the readings are saved per pixel. The pixel array is not perfectly linear in
wavelength, however. In case your application needs perfectly spaced wavelengths, you can
select this option, and the readings will be interpolated. You can enter start and stop
wavelengths, and wavelength increments.
Save to JCAMP-DX in Equidistant Format:
JCAMP-DX can be used with equidistant x values or with non-equidistant x values. With
equidistant x values, the readings will be interpolated. AvaSoft 7 did not offer this choice, it
would always output equidistant JCAMP files.
Save to GRAMS-SPC in Equidistant Format:
GRAMS-SPC can also be used with equidistant x values or with non-equidistant x values. With
equidistant x values, the readings will be interpolated. AvaSoft 7 did not offer this choice, it
would always output equidistant GRAMS-SPC files.
4.1.15.2
Look and Feel
The on screen spectral line width in AvaSoft can be changed here. Only after restarting
AvaSoft the new line width will be shown. Recommended value is 1 or 2, a value of 0 means
no change will be made.
4.1.15.3
Windows Options
We have seen some problems with PC’s relating to power management.
On some PCs, measurement stops as soon as the screen saver kicks in. In this option screen,
you can disable the screen saver during measurement.
Some PCs try to conserve battery capacity by cutting the power to the USB ports, and fail to
notice ongoing measurements. In this screen, you can also disable power saving.
4.1.15.4
USB vs Ethernet
This option allows you to use AvaSpec devices with the AS7010 board when connected
through their Ethernet interface. If you want to connect your spectrometer through the
Ethernet interface, select the bottom radiobutton ‘Ethernet/USB’, press ‘OK’ and restart
AvaSoft. This selection will not affect spectrometers without an Ethernet port.
See also section 4.1.7 about selecting the Ethernet spectrometers
4.1.15.5
Save Spectra Periodically
When saving multiple scans, you select the number to scan here, and also the time delay
before the start of the saving, and the time delay between consecutive savings. Only raw
files are stored here.
You can also select to save data as a single StoreToRam file here. You can load and view this
file in a 3D spectrum window, where you may also save the data into separate files. Another
way to save spectra periodically is available in live mode see ‘Save Live Output Periodically’
Button.
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4.1.15.6
Correct for Drift Channel
Introduction
When measuring the reflectance of a white reference tile or the transmittance of a reference
solution against time, the output should theoretically remain 100% +/- noise. In practice the output
value will not remain exactly fluctuating round 100%, but the signal can slowly drift away. The
cause for this drift in the measurement system can be a change in temperature in the optical bench
which causes micro bending of the components that focus the light at the detector, but also a drift
in the light source that is used to illuminate the reference sample.
To correct for the drift in the system, it needs to be measured first. If a 2-or multiple-channel
spectrometer is available, the measured deviation from 100% at a reference channel can be used to
compensate the measured data at the sample channel. The sample and reference data can be
measured simultaneously and the measured data at the reference sample can be used directly to
correct the sample data. Disadvantage of the “correct for drift by spectrometer channel” is that the
data for reference and sample are measured by using two optical benches which may react
differently to temperature changes. If the drift is mainly caused by the light source (such as a
difference in flash intensity of the AvaLight-XE), this method of correction is recommended.
A disadvantage of this method is that it will not correct for drift caused by temperature changes of
the optical bench.
Correct for Drift by Spectrometer Channel
This option is only available if the spectrometer system has one or more slave channels. One
spectrometer channel will be used as a reference channel, which will continuously measure the
reference spectrum (e.g. the white tile in reflectance measurements or the cuvette holding the
reference solution in transmittance measurements). Changes in this reference signal, e.g. because
of drift in the light source, will be used to correct the data of the other (selected) spectrometer
channels. The wavelength range over which the data can be corrected will be the overlapping
wavelength range between reference spectrometer channel and the spectrometer channel to be
corrected.
The option screen will be shown in which the reference channel and one or more (depending on the
number of spectrometer channels that are available) channels to be corrected can be selected.
After selecting the right setup, click the OK button
To disable the correct for drift option, the menu option must be set to off again.
4.1.15.7
External Trigger Setting
If the external trigger setting is enabled the spectrometer will wait until a TTL signal at pin
6 of the DB26 connector gets high and will then start the integration time. The delay
between the rising edge of the TTL pulse and the start of the integration time cycle
depends on the spectrometer type, as shown in the table below.
Spectrometer Type
AvaSpec-128-USB2
AvaSpec-256-USB2
AvaSpec-1024-USB2
AvaSpec-2048-USB2
AvaSpec-2048L-USB2
AvaSpec-3648-USB2
(clearbuffer mode)
AvaSpec-NIR256-1.7,
AvaSpec-NIR256-2.0TEC,
AvaSpec-NIR256-2.5TEC
AvaSpec-NIR512-2.5-HSC
AvaSpec-NIR256-1.7TEC,
Minimum Delay [s]
9
0.80
0.80
1.28
3.28
0.28
Maximum Delay [s]
60
0.84
0.84
1.30
3.30
0.30
0
531
600
533
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AvaSpec-NIR256-2.2TEC
4.92*
5.75*
AvaSpec-NIR512-1.7TEC,
AvaSpec-NIR512-2.2TEC
4.92**
5.75**
AvaSpec-2048x14-USB2
-2170
0
AvaSpec-2048x16-USB2
-1820
0
AvaSpec-2048x64-USB2
-2400
0
AvaSpec-2048x64TEC-USB2
-9700
0
AvaSpec-HS1024x58-USB2
-5220
0
AvaSpec-HS1024x122-USB2
-6240
0
AvaSpec-2048XL-USB2
0.28
0.30
AvaSpec-2048CL-USB2
0.90
0.92
* = 4.92 – 5.75 µs with FPGA version 6.4 and later, 137.5 – 138.3 µs with FPGA version 6.3
** = 4.92 – 5.75 µs with FPGA version 6.4 and later, 251.1 – 252.8 µs with FPGA version 6.3
Trigger Type Edge
When this mode is selected one or multiple scans will be started at the rising edge of a TTL pulse at
pin 6 of the DB26 connector. The delay between the rising edge and the actual start of the
integration time can be found in the table above.
Trigger Type Level
When this mode is selected the spectrometer will start to accumulate data (take scans at the
selected integration time) at the rising edge of the TTL pulse and will continue to do so as long as
the TTL signal remains high. When the signal becomes low, the average of the accumulated data
(except for the last scan) will be displayed or saved. This mode is especially useful for conveying
belt applications, when a product needs to be scanned, independent of the transport speed.
Scans per trigger
If a number of scans is set to a value higher than 1, the spectrometer will accumulate multiple scans
on every rising edge of the external TTL trigger. This setting is overruled when level triggered is
enabled.
4.1.15.8
Use Non-linearity Correction
If you have ordered a non-linearity-correction calibration with your spectrometer, you can
enable or disable the feature here.
4.1.15.9
Laser Induced Breakdown Spectroscopy
Enable L.I.B.S.:
You must check this box to enable L.I.B.S. The other options choices will now be shown.
L.I.B.S. Mode:
Depending on your detector, you can select one of 3 modes here.
Spectrometer Triggers Laser (Output at pin 23). This option is only enabled with the AvaSpec-2048USB2 and the AvaSpec-2048XL-USB spectrometers
Laser Triggers Spectrometer (Input at pin 6). This option can be selected with all spectrometers.
Laser Triggers PreScan Spectrometer (Input at pin 6). This option is only available with the AvaSpec3648-USB2 spectrometer.
Measurement Settings:
You can set the number of measurements here, including the number of averages per scan.
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If you check the Autosave Measurements box, the spectra will be saved after each measurement and
can be displayed afterwards like any other saved measurement.
The integration delay can be set either fixed or variable. If the ‘Variable’ checkbox is left
unchecked, the required fixed integration time delay can be entered. If the ‘Variable’ checkbox is
checked, you can enter the first and the final integration time delay. The integration time delay for
all measurements in between will be linearly interpolated.
Spectrometer Triggers Laser:
The LIBS settings in the lower box of the window are only relevant in the first mode, where the TTLOut at pin 23 is used to trigger the laser.
Interval between scans:
This setting determines the frequency at which the laser is fired.
The Pulse Width parameter is the width for the laser pulse in microseconds during which the TTLOut at pin 23 is set.
External Trigger options can be set to:
- Off, meaning the measurement sequence is software controlled. The frequency of the TTLOut at pin 23 is determined by the “Interval between scans [ms]” parameter.
- First, meaning the first scan is controlled by an external hardware trigger at pin 6. Then
every next scan in the measurement sequence is started by the software, using the “Interval
between scans [ms]” parameter to determine the frequency of the TTL-Out at pin 23.
- All, meaning every scan is started on hardware trigger, optionally using the Laser Delay
parameter.
The spectrometer will be setup in external trigger mode and requires one external trigger input at
pin 6 for each scan (totaling Number of measurements * Averages trigger signals) to complete the
sequence. The “Time Between scans [ms]” parameter becomes irrelevant when using this setting,
because the frequency will be determined by the frequency of the trigger pulses received at pin 6.
The Laser Delay parameter is the time in microseconds between receiving the external trigger at pin
6 and sending out the Laser pulse at pin 23 to fire the laser.
4.1.15.10
Merge Channel Settings
You can merge overlapping multiple channels into a merge group. The Merge Channel
Settings screen lets you select which channels will be combined in merge groups.
4.1.15.11
Electronic Optical accessories
This selection will let you use devices like the Fiber Optic Multiplexer, the Fiber Optic
Switch, the AvaAbsorb, the Beam Combiner or the Beam Splitter with AvaSoft 8. Please
refer to the manuals that accompany these options.
4.1.16
-
‘Home’ ribbon tab, ‘Sync’ Button
Pull down menu:
No Hardware Synchronization
Master: spectrometer ID
For synchronization of scans a master sync spectrometer needs to be dedicated, in Multichannel
platforms usually the leftmost spectrometer (as seen from the front) is assigned as master sync by
Avantes. Please note that separate spectrometers need to be connected with synchronization cables
for this option to work, otherwise only the master spectrometer will scan just once, and the
program will start to wait for data that will not arrive. You can switch off the synchronization by
selecting the top option again (No Hardware Synchronization)
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4.1.17
‘Home’ ribbon tab, ‘Tools’ Button
A pull down menu is shown with two choices:
4.1.17.1
Full Width Half Max (FWHM)
The Full Width Half Maximum of a peak is the bandwidth (in nanometers) for which the
intensity is higher than half of the maximum intensity of that peak. This utility is used
mostly measuring the output of laser diodes. For correct FWHM calculations, the intensity
needs to be corrected for the dark data. Therefore it is recommended to enable the
‘Dynamic Dark’ option or measure in Scope minus Dark mode.
The FWHM can be displayed in two different ways:
-
Show all FWHM and Peaks in Table
This option allows you to open the table in which Wavelength, Intensity and FWHM are
displayed and updated after each scan (see figure below).
The results can be saved any time by clicking the Save button. The file is a text file with the file
extension .fwm. It can be opened with any text editor, e.g. notepad.
The channel selector at the top of the FWHM dialog can be useful if there are multiple
spectrometers connected, and you want to switch between channels.
- Show FWHM in graph
Right-click with your mouse in the graphical region and select FWHM to calculate an FWHM value of
the peak the mouse is over. An area of the chart will be marked in a transparent color with the
FWHM width. The FWHM value will be printed to the top
right of this area. See also subparagraph 4.4.40.
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4.1.17.2
Peak Tracing (pulsewidth fsec)
This application will let you calculate a laser pulsewidth from the wavelength and FWHM of
a peak.
First zoom in on peak of interest and use right mouse button to determine peak and FWHM,
next select Peak Tracing via ‘Tools’ button. In Femto window (see figure below) peak
wavelength can be entered so that it can be monitored.
When Save button is pressed results are written to a text file named Femto Peak Tracing.lad
4.1.18
‘Home’ ribbon tab, Application Buttons
4.1.18.1
‘Spectrum’ Button
This button will open a new spectrum application window. The spectrum application is
described in section 4.4.
4.1.18.2
‘Spectrum3D’ Button
This button will open a new 3D spectrum application window. The spectrum3D application is
described in section 4.5.
4.1.18.3
‘TimeSeries’ Button
This button will open a new Timeseries application window. This application is described in
section 4.6.
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If there are more applications enabled for your spectrometer, you can open new application
windows with extra buttons to the right of the ‘TimeSeries’ button.
4.1.19
‘View’ ribbon tab, ‘Dock All’ Button
This button will redock all undocked windows.
4.1.20
‘View’ ribbon tab, ‘Tile in Grid’ Button
This button will arrange all windows in a grid, each window will be undocked.
4.1.21
‘View’ ribbon tab, ‘Tile Vertically’ Button
This button will arrange all windows side by side, each window will be undocked.
4.1.22
‘View’ ribbon tab, ‘Tile Horizontally’ Button
This button will arrange all windows from top to bottom. Each window will be undocked.
4.1.23
‘View’ ribbon tab, ‘Set Panel Indicators’ Button
Pull down menu:
- Progress Bar
- Scan Counter
- Detector Temp and Setpoint
The spectrometer windows display a number of parameters that change with each scan. In this
menu, you can choose which ones to show. The detector temperature and setpoint will only be
shown in the spectrometer window if your spectrometer is TE cooled.
4.2 Experiment Window
Allows you to set the name and folder location of your experiment, which allows you to control
where data files are saved.
The setup data for the experiments can be saved to and reloaded from disk, which allows you to
continue experiments where you left off, without reentering all of the setup data.
You can load and save the setup data from the main window, under the ‘File’ tab, with the ‘Load
Experiment’ and ‘Save Experiment’ buttons.
4.3 Spectrometer Window
4.3.1
Friendly name ‘Spectrometer Settings’ dialog
You can change the color of the line in the ‘Graph Parameters’ dialog, described in the ‘Spectrum’
application, see section 4.3.3.1.
4.3.2
Collapse / Expand button
Use the buttons to free up screen space, and to show the spectrometer window again, when
necessary.
4.3.3
‘Spectrometer Settings’ Button
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4.3.3.1
Measurements Settings
This screen allows you to set the friendly name of the spectrometer, which will be shown in most
screens of the program. You can also set integration time, averaging and smoothing number, start
and stop wavelength (you can reduce the number of pixels the spectrometer uses here, which may
significantly speed up processing and reduce the size of data files).
To get a smoother spectrum without losing information it is important to set the right smoothing
parameter in the software. The optimal smoothing parameter depends on the distance between the
pixels at the detector array and the light beam that enters the spectrometer. For the AvaSpec-2048,
the distance between the pixels on the CCD-array is 14 micron.
With a 200 micron fiber (no slit installed) connected, the optical pixel resolution is about 14.3 CCDpixels. With a smoothing parameter set to 7, each pixel will be averaged with 7 left and 7 right
neighbor pixels. Averaging over 15 pixels with a pitch distance between the CCD pixels of 14 micron
will cover 15*14 = 210 micron at the CCD array. Using a fiber diameter of 200 micron means that we
will lose resolution when setting the smoothing parameter to 7. Theoretically the optimal smoothing
parameter is therefore 6. The formula is ((slit size/pixel size) – 1)/2
In the table below, the recommended smoothing values for the AvaSpecs spectrometer are listed as
function of the light beam that enters the spectrometer. This light beam is the fiber core diameter,
or if a smaller slit has been installed in the spectrometer, the slit width. Note that this table shows
the optimal smoothing without losing resolution. If resolution is not an important issue, a higher
smoothing parameter can be set to decrease noise against the price of less resolution.
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Slit or
Fiber
AvaSpec128
AvaSpec256
1024
AvaSpecHS
1024x58
1024x122
AvaSpec3648
AvaSpecNIR256
AvaSpecNIR512
n.a.
0
Pixel
24 µm
0
0
AvaSpec2048,
2048L,
2048x14,
2048x16,
2048x64,
2048XL
2048CL
Pixel
14 µm
0
0-1
Pixel
63.5 µm
Pixel
25 µm
Pixel
8 µm
0
1
Pixel
50 µm
n.a.
n.a.
Pixel
25 µm
n.a.
0
10µm
25µm
n.a.
n.a.
50µm
0
0-1
0-1
1-2
2-3
0
0-1
100µm
0-1
1-2
1-2
3
5-6
0-1
1-2
200µm
1
3-4
3-4
6-7
12
1-2
3-4
400µm
2-3
7-8
7-8
13-14
24-25
3-4
7-8
500µm
3-4
9-10
9-10
17
31
4-5
9-10
600µm
4
11-12
11-12
21
37
5-6
11-12
You can set the number of scans for StoreToRam mode.
This mode allows you to measure a fixed amount of scans as fast as possible, without the overhead
of USB communications. The scans are stored in the internal memory of the AvaSpec, and the
results are only sent to the computer after the last measurement has been made.
You can, for example, store as much as 19784 full pixel scans with the AvaSpec 102, which has 102
pixels and a fastest integration cycle of 0.1 msec. By limiting the wavelength range in the
measurement (‘Setup’, ‘Wavelength Calibration Coefficients’, change the ‘Start at’ and ‘Stop at’
fields) you can extend the number of scans to a maximum of 65504 scans.
When you use a spectrometer with more pixels, the number of full pixel scans is proportionally less:
For example, with the AvaSpec-2048-USB2, the number of full pixel scans is 1013, and the fastest
integration cycle is 1.05 msec. The AvaSpec-2048Mini and the AvaSpec-2048L-EVO have much more
memory, allowing for 7783 and 16383 scans of 2048 pixels respectively.
If you enter more scans, the application will return the maximum amount that could be made with
the selected wavelength range, and change the number in the edit field.
All spectrometers allow you to extend the amount of Store To Ram scans by limiting the wavelength
range.
Note that the time needed to transport the data to the computer (after the measurement has been
made), can be as long as 50 seconds, if you select a very large number of scans.
Only for AvaSpec NIR spectrometers an extra option Sensitivity Mode exists below Saturation
Detection option. This mode can be set to Low Noise or High Sensitivity.
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The Toshiba detector, TCD1304 (3648 pixels), can be used in 2 different control modes:
1. The Prescan mode (default mode with option “Prescan enabled” set to on).
In this mode the Toshiba detector will generate automatically an additional prescan for
every request from the PC, the first scan contains non-linear data and will be rejected, the
2nd scan contains linear data and will be showed on the screen and/or saved. This prescan
mode is default and should be used in most applications, like with averaging (only one
prescan is generated for a nr of averages), with the use of an AvaLight-XE (one or more
flashes per scan) and with multichannel spectrometers. The advantage of this mode is a
very stable and linear spectrum. The disadvantage of this mode is that a minor (<5%) image
of the previous scan (ghostspectrum) is included in the signal.
This mode cannot be used for fast external trigger and accurate timing, since the start of
the scan is always delayed with the integration time (min. 3.7 ms).
2. The Clear-Buffer mode (option “Prescan enabled” set to off)
In this mode the Toshiba detector buffer will be cleared, before a scan is taken. This clearbuffer mode should be used when timing is important, like with fast external triggering. The
advantage of this mode is that a scan will start at the time of an external trigger, the
disadvantage of this mode is that after clearing the buffer, the detector will have a minor
threshold, in which small signals (<2000 counts) will not appear and with different
integration times the detector is not linear.
Another option you can select in the ‘Measurement Settings’ is Dynamic Dark mode.
The pixels of the CCD detector are thermally sensitive, which causes a small dark current, even
without exposure to light. To get an approximation of this dark current, the signal of some optical
black pixels of the detector can be taken and subtracted from the raw scope data. This will happen
if the correct for dynamic dark option is enabled. As these optical black pixels have the same
thermal behaviour as the active pixels, the correction is dynamic.
Some detector types (AvaSpec-2048/2048L/3648) include dedicated optical black pixels. At these
optical black pixels, the intensity and thermal behaviour is the same as the active data pixels, if no
light falls on the detector. Enabling dynamic dark correction will therefore result in a baseline
fluctuating round zero, and measurement data will be less sensitive for temperature changes than
with dynamic dark correction off.
Some NIR detector types (NIR256-2.0TEC, NIR256-2.5TEC) and the AvaSpec-2048CL also support
dynamic dark, because a few datapixels are blackened during fabrication of the optical bench.
These blackened pixels can then be used for dynamic dark correction.
For spectrometers with dedicated optical black or blackened pixels, the correct for dynamic dark
option can be switched on or off by clicking this menu option. The option is on if the menu option is
preceded by a checkmark which is the default state. If the connected spectrometers don’t have
optical black or blackened pixels, the correct for dynamic dark menu option will not be available.
This is also the case for the back illuminated detectors in the AvaSpec-2048x14, 2048x16 and
2048x64, 1024x58, 1024x122, 2048XL. These detectors don’t include optical black pixels, but a few
elements in the shift register are used for correcting the raw data.
Note that this option is different from the dark current that needs to be saved before any
transmittance or absorbance measurements can be taken (Save Dark Spectrum button). If the
correct for dynamic dark option has been changed, it will be necessary to save a new dark and
reference spectrum because the raw data has been changed.
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4.3.3.2
Digital IO
TTL Shutter on Save Dark
To use the automatic TTL Shutter on Save Dark option, an interface cable needs to be connected
from the spectrometer to the light source with shutter (AvaLight-HAL-S, AvaLight-DHc, AvaLightD(H)-S-(DUV) ). The interface cable between TTL-shutter and spectrometer is a 26 pin to 15 pin
cable (IC-DB26-2).
The TTL switch at the light source needs to be in TTL-position. In AvaSoft, the menu option
‘Activate TTL Shutter on Save Dark’ needs to be enabled in the Digital IO screen. If this option is
enabled, the TTL will close the shutter of the light source at the moment the dark data is saved.
After the dark has been saved, the shutter will be opened automatically.
Save Spectra on Digital Input
The DB26 connector pins 7, 16 and 24 may be used to connect external switches, such as photo
switches, to save a spectrum, reference or dark. This is especially useful for automated sampling in
a process control environment with periodical updates of dark and reference signals. It is
recommended to enable the Activate TTL shutter on Save Dark in combination with the Save dark on
Digital Input setting. You can select the action taken on each pin in the Digital IO form.
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4.3.3.3
Wavelength Coefficients
In this dialog, you can manually change the wavelength calibration coefficients, you can perform a
new wavelength calibration and you can restore the original factory calibration which is stored in
eeprom.
The wavelength  that corresponds to a pixel number (pixnr) in the detector in the spectrometer
can be calculated by the following equation:
 = Intercept + X1*pixnr + X2*pixnr2 + X3*pixnr3 + X4*pixnr4
in which Intercept and X1 to X4 correspond to Intercept and First to Fourth Coefficient in the screen
above. For example, if we want to calculate the wavelength at pixel number 1000, using the
numbers in the screen above, the wavelength becomes:
=
=
409,672 +
0,28770*1000 +
-9.54557E-6*1000*1000 +
-1,40802E-9*1000*1000*1000
686,418 nm.
In the ‘Load or Save Calibration Sets’ panel, you can enter a file name and save the current set of
calibration coefficients to disk. You can also load a previously saved calibration set from disk. A
maximum of 4 calibration sets can be stored with each spectrometer.
If a Wavelength Calibration light source is available, together with suitable optical fibers, an
automatic wavelength calibration can be performed. Press the ‘Calibrate’ button to show the right
part of the form. The peaks for the Mercury-Argon calibration source (AvaLight-CAL) are loaded by
default. It is also possible to import the peaks that will be used in the calibration from a file by
selecting the “Read from File” radio button above the “Find Peaks” button. This option allows you
to import peaks for different calibration sources such as the Avalight-CAL-NEON or AvaLight-CAL-AR.
The files that can be imported are in ASCII format and can be edited with any text editor, e.g.
Notepad.
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The extension for these files is “.lit” and the data is presented in three columns:
<wavelength in nm> <intensity in arbitrary units> <peak order>
An important precondition for a successful auto calibration is the absence of saturation. The easiest
way to assure this is to select the ‘Saturation Detection’ option (section 4.3.3.1). If the
spectrometer is saturated at minimum integration time, a fiber with smaller core diameter (e.g. FCIR008-2) needs to be used. As an alternative, the incoming light can be attenuated e.g. by using an
attenuator (FOA-Inline) or neutral density filter.
Perform New Calibration
The procedure to perform an auto calibration is as follows:
-
-
Connect the fiber to the AvaLight-CAL light source and to the spectrometer channel to be
calibrated.
Choose a suitable integration time so as not to saturate the detector. The peaks can be seen
in scope mode.
Show the ‘Calibrate’ panel on the right side of the form by pressing the ‘Calibrate’ button.
Pressing the ‘Find Peaks’ button will make the program look for a number of peaks; initially
it will look for 5 peaks.
The number of peaks to look for can be altered. A new search can be performed by pressing
the ‘Find Peaks’ button again. The peaks are shown in 3 columns. The first column shows
the position of the peaks found. The second column shows the position of a suggested
standard peak, if available. The last column lists the difference between the first two
columns. You can edit the values of the second column by selecting them with the mouse.
Select the polynomial order. In most cases a third order polynomial will show an excellent
fit (see figure above)
The “include 2nd order peaks” option can be enabled if second or third order peaks should
be added to the list of available literature peaks (e.g. 507.30 nm as second order peak for
253.65). In most spectrometers, the second order effects are eliminated by filters or
coatings, but if these options have not been added to the spectrometer, and second order
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peaks are available, then these can be included in the calibration. The central column cells
will be marked green if a second order peak is found and yellow if a third order peak is
found.
- Press the ‘Calculate’ button. If your calibration is successful, you will be asked to confirm
new coefficients.
Select ‘OK’ and the new calibration will be applied immediately.
At least 3 peaks are needed to successfully complete a new calibration. Try to calibrate with more
peaks. Selecting too many peaks can however lead to peaks that cannot be matched with standard
wavelengths.
Restoring the Original Calibration
It is possible to restore the calibration coefficients to their original values, i.e. the values that
AvaSoft was shipped with. If a new calibration was performed with a limited number of peaks, or
over a limited wavelength range, the results could be less favorable.
You can undo unwanted changes to the calibration by clicking the ‘Restore Factory Settings’ button.
The ‘Restore Factory Settings’ button restores the original wavelength calibration coefficients that
were saved to the EEPROM during factory calibration.
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4.3.3.4
Light Sources Control
The AvaLight-LED needs to be attached to a AvaSpec-USB2 by connecting an IC-DB26-2 interface
cable between the high density 26 pole Sub-D connectors at the AvaSpec-USB2 and the 15-pole DB
connector of the AvaLight –LED (DO1 – pin11).
The frequency can be set between 500 Hz and 300 kHz, the duty cycle between 0 and 100%.
If used with a multichannel system, all channels can have their own independent PWM setting for
both frequency and duty cycle.
To disable the PWM output, simply enter 0 under the Duty Cycle.
This AvaLight-XE option can be used to enable or disable an external strobe attached to an AvaSpec
spectrometer. The measured light intensity of the AvaLight-XE is independent of the integration
time in AvaSoft. To increase light intensity, the number of pulses per integration interval should be
increased. The maximum frequency at which the AvaLight-XE operates is 100 Hz. This means that
the minimum integration time for 1 pulse per scan is 10 ms. When setting the number of pulses e.g.
to 3, the minimum integration time becomes 30 ms. It is recommended to keep the integration time
as low as possible to avoid unnecessary increase of noise.
The AvaLight-XE needs to be attached to an AvaSpec-USB2 by connecting an IC-DB26-2 interface
cable between the high density 26 pole Sub-D connectors at the AvaSpec-USB2 and the 15-pole DB
connector of the AvaLight -XE. If used with a multichannel system, make sure that the AvaLight-XE
is connected to the master sync spectrometer, only the number of flashes per scan set for the
master synch spectrometer will determine flash rate. To disable the strobe, simply enter 0 under
the Number of Flashes per scan.
The Laser Control option lets you select Integration Delay, Laser Delay and Laser Pulse Width.
The Laser Pulse Width is the time in microseconds that the TTL signal at pin 23 is set.
The Laser Delay parameter is the time in microseconds between receiving the external trigger at pin
6 and sending out the Laser pulse at pin 23 to fire the laser.
The Integration Delay is the time delay in microseconds between the pulse at pin 23 and the start of
the integration time cycle.
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The avaLight-HAL mini/SPHERE option lets you operate this light source by software. When you
check the ‘light source enabled’ checkbox, the lamp is switched on (pin 2 on the HD26 is asserted)
The drop down box on the right lets you select between Normal mode, Long Life mode and High
Intensity mode. Asserting pin 21 on the HD26 selects Long Life mode and asserting pin 22 on the
HD26 selects High Power mode.
4.3.3.5
Irradiance
The Color Temperature value of your light source is used in the calculation of relative irradiance. A
standard value for the Color Temperature is 2850 °K, you can use this value e.g. for the Avalight-Hal
light source with default jumper setting.
Before you can measure absolute irradiance data, you must load an intensity calibration. An
intensity calibration file contains the data which is necessary to convert the Scope data to
Irradiance data. If the spectrometer system has multiple channels, it is important to know that the
calibration data for each spectrometer channel are saved in a separate file. To measure irradiance
data at more spectrometer channels simultaneously, the calibration file for each spectrometer
channel needs to be loaded first. After loading an intensity calibration file, a graph is displayed
which shows the data transfer function for the loaded channel. The irradiance spectrum is
calculated by multiplying the measured scope data (from which a saved dark spectrum is
subtracted) with this data transfer function.
The intensity calibration is loaded from eeprom by default. However, if multiple calibrations are
available for a spectrometer, the eeprom calibration can be overruled by loading a calibration from
file. The filename that holds the intensity calibration needs to include the serialnumber of the
spectrometer channel.
If a calibrated light source such as the AvaLight-HAL-CAL or AvaLight-DH-CAL is available, an
intensity calibration can be performed.
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The following settings need to be entered before starting the intensity calibration:
- Calibration Lampfile
- CC-UV/VIS, Fiber or AvaSphere sample port diameter
For a detailed description of an irradiance calibration, please refer to section ‘Home’ ribbon tab,
‘Start/Stop’ Button.
4.3.3.6
Custom Reflectance
In Transmittance/Reflectance Mode, the transmittance/reflectance at pixel n is calculated using
the current sample, reference and dark data sets in the following equation:
 samplen  dark n 

Tn  C n * 
ref

dark
n
n


Cn is the Custom Reflectance Reference factor at pixel n. In earlier versions of AvaSoft, this factor
was set to 100 for each pixel and could not be modified. In AvaSoft version 6 and later, the custom
reflectance reference factor is default set to 100, but can be set to different values if needed. If
the reflectance spectrum of a “white” calibration tile is known, the data can be read from a file, or
entered in a table in AvaSoft. The resulting custom reference data can be saved and loaded under a
user defined filename.
Click the “Enable” radio button in the “Custom Reflectance Standard” box, and then OK in the
Settings dialog to use the customized reference data in AvaSoft.
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4.3.4
‘Save Dark Spectrum’ Button
4.3.5
‘Save Reference Spectrum’ Button
4.3.6
‘Autoconfigure’ Button
After this button is clicked, AvaSoft starts searching for an optimal integration time.
Depending on the maximum counts in the last scan, the integration time will be
increased/decreased automatically until a scope signal of about 90% of the full scale is
measured.
4.3.7
‘Activate / Deactivate’ Button
This allows you to disable output for this spectrometer, e.g. when you do not want to use a
channel in a multi-channel system. The color of the button will then change to red and the
other buttons will be grayed and inactivated.
4.3.8
‘Progress Bar’ Panel Indicator
If using long integration times or a high number of averages, it can take a few or more seconds
before a new scan is received by the application. To get an indication about how much time it will
take until the next scan arrives, a progress bar can be displayed. After enabling the progress bar by
clicking the menu option, it will be displayed after the next scan has arrived. The progress bar will
be shown only if the time between scans is more than one second. The time between scans is
roughly the integration time, multiplied with the number of averages. However, if the number of
averages is high, the time between scans can get longer because of the overhead time that is spent
on transmitting the high number of average spectra to the PC.
4.3.9
‘Integration Time [ms]’ Panel Indicator
If you click the number, an edit box will appear, allowing you to change the value.
This option changes the CCD readout frequency and therefore the exposure- or integration time of
the CCD detector. The longer the integration time, the more light is exposed to the detector during
a single scan, so the higher the signal. If the integration time is set too long, too much light reaches
the detector. The result is that, over some wavelength range, the signal extends the maximum
counts (65535 for the 16bit ADC) or in extreme case shows as a straight line at any arbitrary height,
even near zero. Entering a shorter integration time can usually solve this. Try to adjust the
integration time, such that the maximum count over the wavelength range is around 90% of the full
ADC scale ( 59000 counts for the 16bit ADC). When at minimum integration the signal is still too
high, an attenuator, a neutral density filter or fibers with a smaller diameter may be used. When
not enough light reaches the spectrometer, likewise a longer integration time should be entered.
It’s also possible to let AvaSoft search for a good integration time by clicking the Autoconfigure
button. If measurements are done in a mode in which reference and dark data are required (all
modes except the Scope modes), then new reference and dark spectra need to be saved after the
integration time has been changed.
4.3.10
‘Averaging’ Panel Indicator
If you click the number, an edit box will appear, allowing you to change the value.
With this option, the number of scans to average can be set. A spectrum will be displayed every
time this number of scans has been made. This spectrum is the average of the number of scans set
here.
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4.3.11
‘Saturated’ Panel Indicator
This field is used to indicate that the spectrometer is receiving too much light at a certain
wavelength range (These ADC counts are evaluated before correcting for dynamic dark, smoothing
or averaging), in which case the label “saturated” will become visible.
4.3.12
‘Custom Reflectance’ Panel Indicator
This field is used to indicate that the Custom Reflectance setting is active, in which case the label
“CR” will become visible.
4.3.13
‘Measurements’ Panel Indicator
The number of scans taken since the start button was clicked.
4.3.14
‘Detector Temp and Setpoint’ Panel Indicator
Shows the present detector temperature and the setpoint value for the NIR2.2/2.5 and the TE
Cooled USB2 spectrometers.
4.4 Spectrum Application Window
This offers a traditional 2D display of signal versus wavelength. You can load earlier measurements
from disk, or show live measurements from attached spectrometers. In Store To Ram mode, only the
last measurement of a series is shown.
4.4.1
‘Home’ ribbon tab, ‘Open’ Button
Loads spectral data in AvaSoft 8 binary format.
4.4.2
‘Home’ ribbon tab, ‘Save’ Button
Saves spectral data in AvaSoft 8 binary format.
4.4.3
‘Home’ ribbon tab, ‘Legend’ Button
Shows information about the series present in the chart. You can edit visibility of the series,
splining of the line, color of the line and width of the line. The default line width value of 2
can be changed with persistence via Option menu item Look and feel. Allowed width range
is 1 to 10. If the series was loaded from disk, you can remove it here by pressing the
‘Remove’ button. You can also add an integral calculation to each of the series. The start
and stop wavelength of the integral calculation can be set, as well as a factor that is
applied. Integrals can also be removed in this screen.
4.4.4
‘Home’ ribbon tab, ‘Scope Mode’ Button
This mode will show a real time raw data signal, with on the Y-axis the read out of the ADconverter and on the X-axis the calculated wavelength.
4.4.5
‘Home’ ribbon tab, ‘Scope minus Dark Mode’ Button
This mode will also show a real time raw data signal, but corrected for the dark signal that
is set.
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4.4.6 ‘Home’ ribbon tab, ‘Absorbance Mode’ Button
In Absorbance Mode, the absorbance at pixel n is calculated using the current sample,
reference and dark data sets in the following equation:
 samplen  darkn 

An   log
 ref n  darkn 
4.4.7
‘Home’ ribbon tab, ‘Transmittance Mode’ Button
In Transmittance Mode, the transmittance at pixel n is calculated using the current sample,
reference and dark data sets in the following equation:
 samplen  darkn 

Tn  100 * 
ref

dark
n
n


4.4.8
‘Home’ ribbon tab, ‘Reflectance Mode’ Button
In Reflectance Mode, the reflectance at pixel n is calculated using the current sample,
reference and dark data sets in the following equation:
 samplen  darkn 

Rn  100 * 
 ref n  darkn 
As described in the spectrometer settings section, the reference (white) percentage of 100
can be customized.
4.4.9
‘Home’ ribbon tab, ‘Absolute Irradiance Mode’ Button
If the Absolute Irradiance Measurements Module has been ordered with AvaSoft, this option
will show the absolute energy output in µWatt/cm2/nm. An elaborate description about the
experimental setup in case of absolute irradiance can be found in the section describing the
irradiance application.
4.4.10
‘Home’ ribbon tab, ‘Relative Irradiance Mode’ Button
If the absolute irradiance application is not available, a light source of known color
temperature is needed as a reference, for example the AvaLight-HAL with color
temperatures of 2850K at default jumper setting
The relative radiance energy at wavelength  is then calculated using the current sample,
the reference and the dark data sets:
S  B * sample  dark 
Where B is the computed component of the spectral distribution of the blackbody radiant
emittance (at user selected temperature in degrees Kelvin), divided by the current
reference data at wavelength 
4.4.11
‘Home’ ribbon tab, ‘Auto Scale Y-axis’ Button
By using this option, the graph will be rescaled on-line. A maximum signal will be shown at
about 75% of the vertical scale.
4.4.12
‘Home’ ribbon tab, ‘Graphic Reset’ Button
When selecting this option, the graph will be reset to the default X- and Y-axes.
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4.4.13
‘Home’ ribbon tab, ‘Preset Scale’ Button
Pull down menu:
- Edit
- Save Current Scale
Pressing this button will set a preset scale.
To preset a scale, you can save the current scale as preset scale by selecting the bottom option
from the pull down menu.
You can also edit the scale first, with the following form, that will appear after selecting ‘Edit’ from
the pull down menu.
4.4.14
‘Home’ ribbon tab, ‘Grid’ Checkbox
With the Grid Enable option activated, a grid will be displayed in the graph.
4.4.15
‘Home’ ribbon tab, ‘Visible Spectrum’ Checkbox
If you select this option, a background will appear that shows the colors of the visible spectrum at
the corresponding wavelengths from 380 to 780 nm.
4.4.16
‘Home’ ribbon tab, ‘Logarithmic’ Checkbox
If you select this option, the Y axis will be displayed with a logarithmic scale, rather than a linear
one.
4.4.17
‘Home’ ribbon tab, ‘Photon Density’ Checkbox
This option will change the Y axis to Photon Counts [uMol/s/m2/nm]. It only applies in Absolute
Irradiance mode.
4.4.18
‘Home’ ribbon tab, ‘Splining On’ Button
This will switch on a cubic spline interpolation of the spectrum.
The spline interpolation can be useful for applications in which the output of line sources (like laser
diodes) is displayed, or for other applications which require a high resolution. Note that for the
AvaSpec-2048 with 2048 pixels, the effect of spline interpolation is not visible if the data is shown
at full scale. The monitor resolution will probably be less than 2048 pixels. The effect of spline
interpolation can only be visualized if the number of detector pixels that are displayed is smaller
than the number of monitor pixels at the x-axis.
In the figure below, the effect of spline interpolation is illustrated. The blue line shows the AD
counts for about 10 pixels, connected by a straight line (linear interpolation). The data for the red
line is exactly the same, but this time the cubic spline interpolation algorithm has been applied,
resulting in data which is smooth in the first derivative and continuous in the second derivative.
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4.4.19
‘Home’ ribbon tab, ‘Splining Off’ Button
Switches off the spline interpolation.
4.4.20
‘File’ ribbon tab, ‘Open Spectral Data’ Button
Loads spectral data in AvaSoft 8 binary format. This option is repeated from the ‘Home’
menu.
4.4.21
‘File’ ribbon tab, ‘Import V7 Spectral Data’ Button
Loads spectral data in AvaSoft 7 binary format.
4.4.22
‘File’ ribbon tab, ‘Save Spectral Data’ Button
Saves spectral data in AvaSoft 8 binary format. This option is repeated from the ‘Home’
menu.
4.4.23
‘File’ ribbon tab, ‘Export Spectral Data’ Button
Pull down menu:
- ASCII
- Excel (New File)
- Excel (Existing File)
- JCAMP
- GRAMS
- Active FWHM (ASCII)
Saves spectral data in one of several popular formats.
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Note that this only exports the LIVE data. To convert existing files, please use the ‘Convert File To’
option in the main window.
You can export to Excel either to a new file, or to an existing Excel file. In the latter case, you will
get a dialog to choose the existing excel file. The data will be added in a column to the right of the
existing data in a separate tab sheet per spectrometer used.
Note that ASCII and JCAMP can be optionally saved in equidistant format (meaning the points are
evenly spaced on the x axis). You will have to select this in the ‘Save Options’ menu, which you can
access by clicking the ‘Options’ button in the main form.
The last option lets you export a table of all selected FWHM values in the window to ASCII.
4.4.24
‘File’ ribbon tab, ‘Copy Graph’ Button
This will store the graph on the clipboard, allowing you to paste it into other applications.
4.4.25
‘File’ ribbon tab, ‘Save Graph As’ Button
Pull down menu:
- Rich Text Format (*.rtf)
- Windows Bitmap (*.bmp)
- Compressed bitmap (*.jpg)
- Portable Network Graphics (*.png)
- Acrobat Reader (*.pdf)
Saves the graph in one of several popular formats. Note that the .rtf format is a Microsoft format,
that will open in MS Word. The saved file holds a .png graph that you can extract from it if
necessary.
4.4.26
‘File’ ribbon tab, ‘Print Graph’ Button
Will open a standard Windows Print dialog.
4.4.27
‘File’ ribbon tab, ‘Live Excel Output’ Button
Will save live spectral data to Excel, either to a single column, where new data overwrites
the old, or to a new column per scan.
4.4.28
‘File’ ribbon tab, ‘Save Live Output Periodically’ Button
Saves complete live spectral data periodically, in AvaSoft 8 format. Remember to first set
this option when spectrometer is not started before being able to save later in ‘Live’ output
mode.
On the bottom of the AvaSoft screen a message will appear with text “Live Output Enabled”
Also live merged spectral data can be stored in scope mode to disk automatically after
selection of a merge group channel.
4.4.29
‘Tools’ ribbon tab, ‘New Integral’ Button
You can also add an integral calculation to each of the series. The start and stop wavelength of the
integral calculation can be set, as well as a factor that is applied. Integrals can be removed in the
screen that is shown after pressing Legend button.
4.4.30
‘Tools’ ribbon tab, ‘Magnify Tool On’ Button
Switches on the Magnify tool. You can select the magnification in the pull down menu.
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4.4.31
‘Tools’ ribbon tab, ‘Magnify Tool Off’ Button
Switches off the Magnify tool.
4.4.32
‘Tools’ ribbon tab, ‘Assign Cursor’ Button
Pull down menu:
- ‘None’
- Spectrometer ID
You can assign a cursor to a Chart series here. The cursor consists of a vertical and a horizontal line.
If you hover over a line, the mouse cursor will change into a ‘splitter’ shape, if you then press the
left mouse button, you can drag the line to another position. The vertical line will snap to the next
pixel position.
The status line will display the cursor position with a value for the wavelength and the amplitude.
You can remove the cursor by selecting ‘None’ in the pull down menu.
4.4.33
‘Tools’ ribbon tab, Cursor Wavelength Edit Box
4.4.34
‘Tools’ ribbon tab, Cursor Tool ‘OK’ Button
You can place the vertical cursor line on a specific wavelength by entering the value in the edit box
and pressing the ‘OK’ button.
4.4.35
‘Tools’ ribbon tab, ‘Spectrum Chart Name’ Button
This option allows you to change the name of the application window.
4.4.36
‘Tools’ ribbon tab, ‘Base Line On’ Button
This will show a horizontal line on the screen, with a value on the left side of the screen. You can
move the line up and down by moving the mouse over it until the cursor changes into a ‘splitter’
shape. Next press down the left mouse button and drag the line up or down.
4.4.37
‘Tools’ ribbon tab, ‘Base Line Off’ Button
This will hide the horizontal line.
4.4.38
‘Tools’ ribbon tab, ‘Show Legend’ Checkbox
If you check this box, a legend will be shown to the right of the chart. Note that this take up a lot of
screen space, as it shows the Friendly name, which can be up to 64 characters.
4.4.39
Status bar
The status bar at the bottom of the spectrum application window is used to display wavelength and
intensity data for the cursor
4.4.40
Peak submenu
When you click the right button of your mouse in the graphical region, a pop up menu will be
shown.
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Click ‘Cancel’ to go back.
Click ‘Find Peak’ to position a cursor line on the peak nearest to the mouse position. The following
procedure is used:
-
-
The wavelength is determined from the position the mouse click occurred.
The data from closest pixel is retrieved
The direction to search for the peak is determined from the neighbor pixels. If both
neighbor pixels have a lower value at the Y-axis than the current pixel, the current pixel is
already a peak. If only one of the neighbor pixel values is higher than the current pixel
value, the peak will be searched in the direction of this higher pixel. If both neighbor pixels
have a higher value at the Y-axis than the current pixel, the current pixel is in a valley. The
peak will in this case be searched in the direction of this neighbor pixel with the highest
value.
The cursor starts moving in the direction, as determined under 3), until it reaches a pixel of
which the value is not higher than the last one evaluated. At this pixel the cursor stops.
Click ‘Find Valley’ to position a cursor line on the valley nearest to the mouse position. This uses
the same procure.
Click ‘FWHM’ to calculate an FWHM value of the peak the mouse is over. An area of the chart will
be marked in a transparent color with the FWHM width. The FWHM value will be printed to the top
right of this area.
Click ‘Integral’ to add an integral value.
Click ‘Clear All’ to clear all Peak, Valley and FWHM markings.
If more than one spectrum is being displayed, a dialog will popup that lets you select which
spectrum will be used by the peak finder or the FWHM calculator.
4.4.41
Find peaks or valleys by CTRL or SHIFT + right mouse button click
If the cursor is visible, you can use it to find the value of valleys or peaks.
When the right mouse button is clicked in the graphical region, while the CTRL key is down, AvaSoft
will follow the procedure described above to run the cursor to the closest peak:
By holding down the SHIFT key instead of the CTRL key, the same procedure will be used to move to
the closest valley.
To mark a peak for which the FWHM values need to be calculated, press the ALT key, and click with
the right mouse button on this peak.
If more than one spectrum is being displayed, a dialog will popup that lets you select which
spectrum will be used by the peak finder or the FWHM calculator.
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4.4.42
Spectrum Info window
If you left click on a graph series in the graphical region, a window will appear with some info about
the spectrum that is shown in the graph. You can also remove the series by pressing the ‘Remove’
button.
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4.5 Spectrum3D window
This shows a 3D display of your data against both wavelength and measurement number. You can
load and display earlier date from disk, or you can display live date from attached spectrometers in
Store To Ram mode. The window includes two charts in 2D, that show data against wavelength and
data against measurement number.
The view of the 3D graph can be adjusted by inverting the Depth axis and the X axis. These axes can
also be transposed, which enables a side view of the graph.
The Y axis is auto scaled by default, this can be undone by unchecking the option in the ‘Adjust
View’ box.
The 2D graphs both have a scrollbar, which allows you to change the third dimension. It is also
possible to display the position of each 2D graph in the 3D graph by displaying a separate highlighted
line that sections the 3D graph. This feature is turned on and off with the ‘Display in 3D Graph’
checkbox at the top-right position of each 2D graph.
The amount of data in the 3D graph and the second 2D graph (Counts vs. Time) has been limited to
prevent computer overload. If more data is present, only one out a calculated number of scans or
pixels is shown. Zooming the graphs will reveal more detail. The fraction of the data that is shown is
indicated in the title of the relevant axis.
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E.g. ‘Time [ms] (1/10)’ means that only one out of every 10 scans is shown.
Note that the first 2D graph (Counts vs. Wavelength) always shows all of the data present. It is
therefore possible to show this graph as a highlighted line in the 3D graph that shows more detail
than the 3D graph itself shows. Zooming in will show more detail in the 3D graph, which will
eventually correct the discrepancy.
The 3D graph can be rotated with the mouse. It has sliders for horizontal and vertical positioning
and for zoom factor.
You can zoom both 2D graphs and the 3D graph will zoom to the selected range after double clicking
the 2D graph. The selected range will then also be shown in the manual selection boxes described
below.
Unzooming the 2D graphs will also unzoom the 3D graph.
Note that zooming and unzooming the 2D graphs is performed the same way as in the main screen of
AvaSoft:
You zoom the graph by clicking the top-left corner of your area to select, hold down the left mouse
button, then draw a rectangle and release the mouse button at the lower-right corner of the area to
select.
You unzoom the graph by clicking anywhere on the graph, hold down the left mouse button, then
drag a rectangle towards the top and left and release the mouse button at any position.
You can pan the 2D graphs by holding down the middle mouse button.
It is also possible to manually select the ranges by entering values in the ‘Select Time Range’,
‘Select Wavelength Range’ and ‘Select Counts Range’ boxes, and pressing the ‘Zoom’ button. Note
that changing the ‘Select Counts Range’ will only have an effect if the ‘Autoscale Y-axis’ option is
unchecked. The ‘Unzoom’ button will undo all your changes.
After your selection is made, you can save the scans to disk by pressing the ‘Save Spectral Data’
button. Each scan will result in a file written to disk, a .raw8 file in scope mode.
If you save the .raw8 files to Excel, using AvaSoft ‘File’-‘Convert File To’-‘Excel’ in the main screen,
the timestamp values from the scans will be written into Excel in row 6 of each data column,
allowing you to use these timestamp values in calculations.
The files are numbered consecutively, a five digit number is affixed to the filename you enter in the
dialog. The starting number of the sequence is the lower limit of the range of selected scans. Only
the presence of a previous version of this file will trigger an overwrite warning in the dialog. All
consecutive scans will silently overwrite previous versions with the same filename.
Note that the scans that are saved are all full scans, only the values entered in ‘Measurement #’
boxes have an effect here. If you want to limit the wavelength range in the files, you will have to do
this in the spectrometer settings screen, as described above.
Although it is possible to use the Store To Ram application to measure huge amounts of scans with a
limited wavelength range, we strongly advise you to save only a limited amount of scans.
If you select 50000 scans to save, the huge number of small files to save will bring your computer to
a near standstill.
For this reason, a warning has been built in when you want to save more than 2500 scans.
You can save the graphs to disk by pressing the ‘Save (rtf) Graph’ button. You can first enter a
comment line, which will be included on the page. Next, you can enter the filename that will be
used to save the graphs. The three graphs will be saved in PNG format, embedded in a single, one
page .RTF file. You can open this file with Microsoft Word, edit it, extract the graphs, change the
size of the graphs, etc.
You can also export the 3D graph to a number of formats by selecting a format from the ‘Export
Graph’ button. You can select between .bmp, .jpg, .png and .pdf formats.
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4.5.1
‘View’ ribbon tab, ‘Channel’ Button
You can select the channel here, in case you have multiple spectrometers attached.
4.5.2
‘View’ ribbon tab, Measure Mode selection
Please refer to section 3.4.4. – 3.4.10 for an explanation of the measure modes
4.5.3
‘View’ ribbon tab, Adjust View selection
Allows predefined changes in the display of the 3D graph
Invert Depth Axis. This changes the order of the depth axis from ascending to descending.
Invert X Axis. This changes the order of the x axis from ascending to descending.
Transpose Axes. Swaps the wavelength and measurement # axes.
Autoscale Y Axis. Uncheck this if you want to manually change the scale of the y axis.
Display Lines. Uncheck this if you want to have a 3D chart without visual lines.
OpenGL rendering. Check this to use OpenGL rendering instead of the default windows rendering.
4.5.4
‘View’ ribbon tab, Change Graph Scale
You can manually set the axis scales of the 3D graph here. Press the ‘Zoom’ button after changing
the values. Press ‘Unzoom’ to return to the full scale. Note that changing the values for ‘Counts’
will only work if the ‘Autoscale Y-axis’ option is unchecked.
4.5.5
‘File’ ribbon tab, ‘Open Separate Spectra Files’ Button
Allows you to select previously saved separate scans into a 3D graph.
4.5.6
‘File’ ribbon tab, ‘Save Scans to Separate Files’ Button
Allows you to save data in the 3D chart to separate files.
4.5.7
‘File’ ribbon tab, ‘Open Single File Data (*.str)’ Button
Loads multiple scans from a single file in Store To Ram format.
4.5.8
‘File’ ribbon tab, ‘Save Single File Data (*.str)’ Button
Saves the scans that are shown to a single Store To Ram file.
4.5.9
‘File’ ribbon tab, ‘Export to Excel’ Button
Exports the scans that are shown to an Excel sheet.
4.5.10
‘File’ ribbon tab, ‘Export to Ascii’ Button
Saves the scans that are shown to a single text file, in table form.
4.5.11
‘File’ ribbon tab, ‘Save Graphs’ Button
Saves the graph in Rich Text Format (*.rtf). Note that the .rtf format is a Microsoft format,
that will open in MS Word. The saved file holds a .png graph that you can extract from it if
necessary.
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4.5.12
‘File’ ribbon tab, ‘Export 3D Graph’ Button
Pull down menu:
- Bitmap (*.bmp)
- Windows Compressed bitmap (*.jpg)
- Portable Network Graphics (*.png)
- Acrobat Reader (*.pdf)
- Saves the graph in one of several popular formats.
4.5.13
‘Settings’ ribbon tab, ‘Input File Sort Order’ Selection
Choose between ‘Alphabetically’ and ‘File Date/Time’ here. Since the Windows File Date/Time
stamp has a limited resolution, it may be necessary to use Alphabetically ordered files.
4.5.14
‘Settings’ ribbon tab, ‘Chart Accuracy’ Selection
You can limit the number of points in the graph here, to increase the screen handling speed. This
will reduce the accuracy of the chart, losing detail.
4.6 Time Series
The Time Series application (or History Channel application) allows you to follow a number of
functions or integrals against time. You can save the resulting values to disk or export them live to
an Excel sheet. You can also drive both digital and analog outputs with the resulting values,
comparing them with preset values.
4.6.1
‘Function’ ribbon tab, ‘Start / Stop’ Button
Used to start and stop recording. If you check the ‘follow main’ checkbox, you can start
recording by pressing the Start button in the main AvaSoft windows, together with
starting the spectrometers.
4.6.2
‘Function’ ribbon tab, ‘New Function’ Button
Use to prepare a new setup file for a time series
4.6.3
‘Function’ ribbon tab, ‘Function’ Selection
Use the drop down box to select time series settings that were saved in an earlier session.
4.6.4
‘Function’ ribbon tab, ‘Device’ Field
Shows the device that is used in the selected time series function.
4.6.5
-
‘Function Entry’
‘Function’ ribbon tab, ‘Time Series Function’ Selection
‘Function’ ribbon tab, ‘Parameters’ Button
Both are used for entry of a time series function.
The functions are defined in a dialog, which can be reached under the ‘Add/Edit Function’ ribbon
tab. Select the function type by changing the radio button to one of the choices: Integral, User,
Peak, Irradiance, Color or Script. Next press the ‘Parameters’ button.
A form will be opened, in which Measure Mode, Function Definition, Function Display Settings,
Function output Settings and Function Digital or Analog Output can be set.
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4.6.5.1
Measure Mode
The eight possible modes (Scope, Scope – Dark, Absorbance, Transmittance, Absolute Irradiance,
Reflectance, Relative Irradiance or Temperature) are described in section 3.4.4 to 3.4.10.
(Temperature mode can be used to display detector or board temperature against time in the user
function type). Note that if the selected measure mode is Absorbance, Transmittance, Reflectance
or Irradiance reference and dark spectra need to be saved or loaded before the Time Series
Measurements can be started.
4.6.5.2
Function Definition
The parameters that need to be entered in the Function Definition Box depend on the Function Type
that has been chosen: Integral, User Defined, Peak, Irradiance, Color or Script.
4.6.5.2.1
Function Definition: Integral Function
In case a function is defined to display the integral versus time, the following parameters can be
set:
Spectrometer Channel. Select the channel in the drop down menu box.
The “from” and “to” edit boxes may be changed to specify the wavelength range in nanometer over
which the integral needs to be calculated.
Finally, a multiplication factor can be entered. The value entered here is multiplied with the
calculated integral.
4.6.5.2.2
Function Definition: User Defined Function
If you want to display the output of a self-defined function against time, a function needs to be
defined first.
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Input Functions:
A comprehensive example of an input function is given in the dialog, but it illustrates only a few of
the functions AvaSoft can handle. A list of allowed operators and functions is given below:
Operators: *, /, +,Functions:
abs
arctan
cos
exp
frac
int
trunk
ln
pi
round
sin
sqr
sqrt
arccos
arcsin arctan2
tan
cotan
hypot
cosh
sinh
tanh
arccosh
arcsinh
arctanh
lnxp1
log10
log2
logn
ceil
floor
log
dettemp
brdtemp
wavval
m
The list of functions includes a fairly complete collection of math functions, some functions have
duplicate names for compatibility reasons (log, logn and ln, wavval and m)
Dettemp(1) will give the detector temperature of device 1
Brdtemp(1) will give the board temperature of device 1
Note that the syntax depends on your setting for decimal separator. If your decimal separator is a
comma, you will need a semicolon between parameters. If your decimal separator is a point, then
you need a comma between parameters.
In the US, the example line reads : ‘Example: log10(m(1,456)+m(1,765)/m(2,321))+0.234*m(3,345)’,
in Europe, it reads : ‘Example: log10(m(1;456)+m(1;765)/m(2;321))+0,234*m(3;345)’.
4.6.5.2.3
Function Definition: Peak Function
In case a function is defined to display a peak versus time, the following parameters can be set:
The Spectrometer Channel. Select the channel in the drop down menu box.
The “from” and “to” edit boxes may be changed to specify the wavelength range in nanometers,
which will be evaluated in the peak search. Finally, a selection can be made to define the Peak
Output: Wavelength or Intensity.
If both wavelength and intensity need to be followed against time, one of the time series can be
used to follow the peak wavelength, and another one to follow the peak intensity.
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4.6.5.2.4
Function Definition: Irradiance Function
With time series irradiance measurements, radiometric parameters can be followed simultaneously
in a graph against time. The following parameters can be set:
- Irradiance parameter: select the parameter from the drop down menu box.
Depending on choice of irradiance parameter, more parameters can be set:
- CIE Standard Observer. The original CIE standard observer functions x, y and z were
defined in 1931, and are known as the 2 degrees standard observer values. The 2 degrees
corresponds with the angle of vision that was used in the experiments to determine these
standard observer values. In 1964, the CIE recommended the use of different observer
values for a higher correlation with visual perception for large samples. These are known as
the 1964 supplementary standard observer, or 10 degrees observer values. Both standards
are still in use, and in AvaSoft, the CIE standard observer can be selected by clicking one of
the radio buttons. The default is 2 degrees.
- Spectrometer Channel: select the channel in the drop down menu box. Make sure white
reference and dark spectra have been saved before for the selected spectrometer channel.
- Wavelength Range: The wavelength range is the spectral range over which the radiometric
output will be integrated. For colorimetric parameters, this range is already set to 380 nm780 nm, and cannot be changed.
- Emittance Parameters: If the source is not inside an integrating sphere, the radiant intensity
(in µWatts/sr) and radiant energy (in µJoule/sr) can be calculated if the distance from
source to diffuser surface has been specified. The radiant flux (µWatts emitted) and
emitted energy (µJoule e.) can be calculated if the geometry of the lamp (in steradians) is
specified.
4.6.5.2.5
Function Definition: Color Function
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With time series color measurements, color parameters or color differences can be followed
simultaneously in a graph against time. The following parameters can be set:
- Color parameter: select the parameter from the drop down menu box.
- Spectrometer Channel: select the channel in the drop down menu box. Make sure white
reference and dark spectra have been saved before for the selected spectrometer channel.
- CIE Standard Observer. The original CIE standard observer functions x, y and z were
defined in 1931, and are known as the 2 degrees standard observer values. The 2 degrees
corresponds with the angle of vision that was used in the experiments to determine these
standard observer values. In 1964, the CIE recommended the use of different observer
values for a higher correlation with visual perception for large samples. These are known as
the 1964 supplementary standard observer, or 10 degrees observer values. Both standards
are still in use, and in AvaSoft, the CIE standard observer can be selected by clicking one of
the radio buttons. The default is 2 degrees.
- Illuminant. The CIE Standard sources A, B or C or one of the illuminants D50, D55, D65 or
D75 can be selected by clicking one of the radio buttons. The default is D65, which is the
most widely used illuminant. It represents the power distribution of average daylight, with a
correlated color temperature of 6500K. The D50, D55 and D75 have correlated color
temperatures of 5000K, 5500K and 7500K. The CIE Standard sources A, B or C represent
respectively: Incandescent light (2854K blackbody), Simulated noon sunlight and Simulated
overcast sky daylight. Note that there is no relation between the illuminant chosen here and
the light source that is used for measuring the color of an object. The selected illuminant is
used in calculation of the color parameters. These color parameters will be different if for
example A will be selected instead of D65, just as the color of an object will look different
in average daylight or in incandescent light (2854K blackbody).
- Reference Color. If one of the color difference parameters (dL, da, db or dE) is selected,
the reference color to which the measured color needs to be compared needs to be defined
as well. You can enter L, a and b values and a product ID for your reference color. You can
also select the reference values from a data base with the ‘Pick’ and ‘DB’ buttons.
4.6.5.2.6 Function Definition: Script Function
A scripting feature has been added to allow you to use more complicated calculations with many
more mathematical and logical functions. Scripts will also allow you to combine the results of
several time series.
AvaSoft uses the Microsoft VBScript language that comes with your copy of Windows. We have
included a help file for VBScript for your reference. You can reach it from the main menu by
selecting ‘Help’, ‘VBScript’. It lists among other things all available operators and functions.
The script references other time series results by their number. The available ones are listed in the
box at the lower left part of the screen above. You must have defined other time series to use
scripts.
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You can start a new script by pressing the ‘New’ button, or load an existing one by pressing the
‘Load’ button. AvaSoft includes a simple script editor. The scripts are plain ASCII files, named
name.script.txt.
An example of a script being edited is listed below.
A starter script has the following contents:
Function Example(value)
Example=0
End Function
You can elaborate on this function, as long as there is a value assigned to Example in the end. In
this case, Example will be assigned the value 0.
You can refer to the other time series with the predefined variables F00 to F99. If you want to use
data from the spectrometer, you will need to assign other time series to e.g. wavelength values or
integrals. The following script defines the function value for Example as the sum of F00 and F01.
Function Example(value)
Example=F00+F01
End Function
Please do not refer to the function value for the script itself, F02 in the case above. You can also
not refer to other functions, if these are themselves assigned to a script. This will result in a
scripting run-time error. If you want to use code from another script, please copy the necessary
lines from that script into the one you’re working with.
Please understand that a script is executed by an interpreter, on a line by line basis. If you make a
syntax error in your script, it will usually only show at the moment the line with the error is
executed, as a run-time error.
Nothing will stop you, for instance, from entering the following script for function 3:
Function Error(value)
Error=F1/0
End Function
Running this script will result
in the run-time error at the
right:
If you refer to channels that are undefined, they will be handled as uninitialized variables by
VBScript, with value 0. This is the case for all uninitialized variables you might use in your scripts.
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Finally, a small example to monitor the integral of a peak between 522 nm and 550 nm, in which an
offset is subtracted. The offset area is the area below of the straight line between the output at 522
nm and the output at 550 nm.
F00 is defined as a user defined input function: m(1;522)
F01 is defined as a user defined input function: m(1;550)
F02 is defined as the zero-based integral between 522 nm and 550 nm.
The script for function Test can then be written as:
Function Test(value)
If F00 > F01 Then
offset = 28*(F01 + (0.5*(F00-F01)))
Else
offset = 28*(F00 + (0.5*(F01-F00)))
End If
Test = F02 - offset
End Function
4.6.5.3
Function Display Settings
Output is displayed graphically against time. The amount of time that will be displayed at the X-axis
can be set manually by clicking the Fixed radio button. If set to Auto, the time axis will be set to 1
minute. The Y-Axis can also be set to Fixed or to Auto. The Auto option will set the Y-axis range to
the minimum and maximum function values that are in the list of measured data points.
The ‘Display No Graphics To Speed Up Data Processing’ option is provided for situations, where an
application requires fast data processing (e.g. more than 10 scans per second).
4.6.5.4
Function Output Settings
The results of a time series experiment will be saved to an ASCII-file except when the option “Do
Not Save Function Output” has been checked. A number of seconds between saving can be entered
for data reduction, in case measurements are carried out over long periods. Entering a value of zero
results in saving every scan. The name of the file to which the data will be saved, can be changed
after clicking the “Change Output Default…” button. You can enable or disable the possibility to
create a backup file during the measurements with the ‘Create Backup File’ checkbox. If this option
is enabled, AvaSoft will create a backup file with the same filename, but with the extension *.bak
(also in ASCII). This backup file is updated every scan and can be used in case the filename that has
been selected has failed to save the data, for instance because of a power failure during the
measurements.
You can export the Data to Excel by enabling the ‘Excel Output’ option.
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The sheet will be called ‘AvaSoft Data’, each time series will use three columns that e.g. for the
first time series will contain the following data:
Column A contains a data/time value, formatted as ‘dd:mm:yyyy hh:mm:ss’.
This is a floating point value, in which the integer part is the day number, starting at January 1,
1900 with day 1. The fractional part represents a decimal time value, where 0.5 is 12:00 h. noon
and 0.75 is 18:00 h.
This way, differences in date/time can be readily calculated by subtracting values, which would be
much more difficult if this was a text representation.
Column B contains a time value, representing the elapsed milliseconds since midnight. This value
does not have a one millisecond resolution. Remember that Windows is not a real-time operating
system. It can, however, be used as a reasonably accurate indicator of the time that passes
between scans.
Column C contains the time series values.
4.6.5.5
Function Digital or Analog Output
AvaSoft 8 lets you operate any available digital and analog output with every time series value. The
output pins on the High Density 26-pole Sub-D connector which are used for this function are listed
in the table below :
HD DB26 pins used by
AvaSoft 8 Digital or
Analog Output
Signal
Pin
Connector
LED
DO2
DO3
SHUTTER
DO5
DO6
DO7
DO8
DO9
DO10
11
2
20
12
3
21
13
4
22
25
AO1
AO2
17
26
GND
8
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The analog output signal is a 0-5V signal, with an 8 bit resolution (0.02V steps).
To set minimum and maximum threshold values for the time series, values can be entered in the
Threshold Off and On boxes. If ‘Invert’ is not selected, the corresponding output pin will be set high
if the time series output value lies between the minimum and maximum value. It will be set low if
the time series output value exceeds the maximum value OR is smaller than the minimum value.
If ‘Invert’ is selected, the corresponding output pin will be set high if the time series output value
exceeds the maximum value OR is smaller than the minimum value. It will be set low if the time
series output value lies between the minimum and maximum value.
If you want to monitor both threshold values, you can assign two (identically configured) time
series.
To monitor a single level, set one threshold value to the desired level, and the other one to a value
that is out of range, e.g. Min to –99999999 and Max to 1000, or Min to 2000 and Max to 99999999.
That way, you will only need a single channel per threshold value.
To specify the time series function range(s) that should be converted into a 0-5V analog output
signal, enter values in the ‘Range Max’ and ‘Range Min’ boxes.
For example, if you enter 100 and 50 for the ranges, the voltage will be calculated as follows:
5.0*(x - 50.0)/(100.0 - 50.0) where x is the output value of the time series.
4.6.6
‘Graph’ ribbon tab, ‘Open’ Button
Opens data from previous sessions and shows them in the graph.
4.6.7
‘Graph’ ribbon tab, ‘Export’ Button
Pull down menu:
- Windows Bitmap (*.bmp)
- Compressed bitmap (*.jpg)
- Portable Network Graphics (*.png)
- Acrobat Reader (*.pdf)
Saves the time series graph in one of several popular formats.
4.6.8
‘Graph’ ribbon tab, ‘Copy’ Button
Copies the time series graph to the clipboard.
4.6.9
‘Graph’ ribbon tab, ‘Print’ Button
Prints the time series graph.
4.7 Chemometry
The Chemometry application was developed to enable on-line concentration measurements with a
spectrometer system.
According to Lambert-Beer’s law, there is a linear relationship between absorbance and
concentration.
A = ε*c*l
Where A is the absorbance (or extinction), ε is the extinction coefficient of the compound to be
measured, c is the concentration and l is the optical path length.
In practice, this relationship is only linear at reasonably low absorbance levels (say less than 2). The
wavelength at which the absorbance is measured must of course be kept constant.
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To take concentration measurements, you will need a spectrometer with either a cuvette-holder or
a dip-probe and a suitable light source.
If you use cuvettes, remember that glass cuvettes will absorb UV light. If your wavelength is in the
UV range, use quartz or polystyrene ones instead.
AvaSoft-Chem can display and save the calculated concentration in two ways:
-
The concentration can be displayed and saved on-line in a separate display window.
You can display and save concentration values against time.
4.7.1
Quick Start: How to make concentration measurements with the
Chemometry application
1. Start the AvaSoft software and click the Start button in the main window.
2. Set up the absorbance experiment with a cuvette holder or a dip-probe measuring the
sample with the lowest concentration, usually your reference. Switch on the light source.
3. Adjust the integration time to get a good reference signal with a maximum around 58000
counts. The easiest way to do this is by using the AutoConfigure button in spectrometer
window.
4. Adjust the number of averages. The higher the better, however the time for a single
absorbance reading must remain practical. If you want to change it, click the Averaging
value in the spectrometer window.
5. Switch off the light source and save a dark spectrum, switch it back on and save a
reference.
6. Change to Absorbance mode by clicking the ‘A’ button in the ribbon. Measure the
absorbance of a sample with a high concentration to find the wavelength and bandwidth of
an absorbance peak to use (most of the time, the wavelength with the highest absorbance is
used.
7. Open a Chemometry window by pressing the icon in the Applications section of the Home
menu in the main window.
8. Calibrate your absorbance readings in the ‘Setup and Calibration’ form. You can also just
use a previous calibration line, as it can be saved to disk under a user defined filename and
reloaded at the start of the application.
9. Switch to the ‘Measurement’ form to see the concentration readings. Press the Start button
to record the readings.
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4.7.2
Setup and Calibration form
You need to measure a number of samples with known concentration to create your own calibration
file(s). After a calibration has been saved, it will be loaded automatically the next time the
application is started. Once a calibration has been saved, it can be loaded later on and modified if
needed.
4.7.2.1
Spectrometer section
Select the spectrometer you want to use in the pull down menu. The plugin will check if the
spectrometer supports the test parameters and will reject it with the message ‘Device xxx' does not
support these parameters please select another device or change the parameters’, dependent on
the maximum amplitude.
4.7.2.2
Test parameters section
Test Name
This is the ID for the test, this name is also used for referencing the calibration data.
Wavelength
This is the primary wavelength for the measurement.
Width
The bandwidth for the measurement. The program will integrate the absorbance values from
“Wavelength minus Width” to “Wavelength plus Width” and uses this integral as the absorbance
value in the concentration calculations.
Units
The concentration units for the measurement. The raw absorbance values will be converted to
concentrations with this unit.
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Decimals
The number of decimals for the concentration result. Absorbance values have a fixed number of 3
decimals.
Use Side wavelength
This option allows for dichromatic measurements, measurements in relation to another wavelength.
The correction will be done on absorbance level, before converting to concentration:
𝐴𝑏𝑠 = 𝐴𝑏𝑠𝑝𝑟𝑖𝑚𝑎𝑟𝑦− 𝐴𝑏𝑠𝑠𝑖𝑑𝑒
The side wavelength will use the same width as the primary wavelength.
Use Absorbance blank
A blank value can be subtracted to remove static offset. The value is subtracted on absorbance
level:
𝐴𝑏𝑠 = 𝐴𝑏𝑠𝑝𝑟𝑖𝑚𝑎𝑟𝑦− 𝐴𝑏𝑠𝑠𝑖𝑑𝑒− 𝐴𝑏𝑠𝑏𝑙𝑎𝑛𝑘
Read blank button
This will fill in the absorbance blank value.
Open / Save Test Definition button
Test definitions can be loaded and saved with these buttons. The test definitions are stored in xml
format with the extension .tdf.xml. If a definition is loaded, the plugin will also check for a
calibration definition file (extension cal.tdf) with a filename equal to the loaded test name. Note
that this is not necessarily the test definition file name. All files are stored under the subdirectory
‘\chem’ in the current experiment directory.
4.7.2.3
Test Calibration section
Calibrating the test is done to determine the relation between Absorbance and Concentration. This
relation is a function of the first or second order. The calibration is performed by reading the
absorbance values of fixed concentrations. These fixed concentrations are called concentration
points or calibrators. The calibrators should be entered in the calibration grid under the column
‘Conc’. A calibrator measurement can be done by selecting the ‘Abs’ cell and pressing the ‘Read
Absorbance #n’ button.
Use 0-Calibrator button
Pressing the Use 0-calibrator button will enter the value to 0.000 Abs.
Calculate Curve radio buttons
Select either a Linear (first order) or a Quadratic (second order) fit.
Calculate Calibration button
After all calibrators are measured, the curve can be calculated by pressing the Calculate Calibration
button. A linear (1st order) or quadratic curve (2nd order) can be calculated. After pressing the
Calculate Calibration button the calibration result must be accepted by the operator. If this is
accepted the calibration is stored under the current test name and the calibration date is set.
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The polynomial and standard deviation are displayed. A graphic presentation of the relation
between Absorbance and concentration will also be shown.
Load Calibration button
Other calibrations can be loaded. Note that the values of a loaded concentration are stored under
the current test name if the calculation curve is recalculated.
4.7.3
Measurement form
In the measurement form the readings will be shown continuously if the application is in run mode.
Measurements can also be recorded by pressing the start button. The time interval and
measurement time can be set. The time interval is the interval between consecutive readings. The
measurement time is the total time of the measurement. Recording will stop after this period has
elapsed. The recorded graph can be printed or copied to the clipboard. The graph is automatically
annotated with the test name, spectrometer and date/time stamp.
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4.8 Color
The AvaSoft Color Application has been developed to perform on-line color measurements with a
spectrometer system. It can be used for reflective color measurements, in earlier versions of
AvaSoft called “color of object measurements”. The CIE 1976 L*a*b* color parameters are
calculated, as well as other frequently used parameters, like Hue, Chroma and X, Y, Z.
These parameters can be displayed in a CIELAB chart or in a graph versus time. It’s also possible to
save the measured L*a*b* values online to a database and use one of the products from the database
as a reference color. By comparing the measured L*a*b* values to the stored database values, color
differences (ELab, L*, a*, or b*) can be measured as well.
Emissive color measurements can be done to measure the color of a light source (e.g. LED’s). These
measurements require an irradiance spectrum to calculate the color parameters x, y and z. With
AvaSoft’s Irradiance application, it is possible to perform irradiance measurements with a lot higher
accuracy than when using the relative irradiance mode (which assumes a perfect blackbody light
source with known color temperature). For this reason the emissive color or “color of light”
calculation is one of the features in the Irradiance Application.
4.8.1
Color of an Object - Background
The color of an object can be expressed by the CIE 1976 (L*a*b*) color space. L* describes the
lightness of the color. A positive value of a* describes the redness of the color, a negative a* the
greenness. Similarly, yellowness or blueness is expressed by coordinate b*, which is positive for
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yellow and negative for blue. The L*a*b* values are derived from the CIE tristimulus values X, Y and
Z of the sample (object) and the standard illuminant tristimulus values X n, Yn and Zn.
The standard illuminant tristimulus values for Xn, Yn, and Zn are constant and depend only on the
type of standard illuminant that has been chosen.
The CIE tristimulus values X, Y and Z of the color of an object are obtained by multiplying the
relative power P of a standard illuminant, the reflectance R (or the transmittance) of the object,
and the CIE standard observer functions x, y and z (2 degrees or 10 degrees angle). The integral
of these products over all the wavelengths in the visible spectrum (380 to 780 nm with a 5 nm
interval) gives the tristimulus values.
The chromaticity coordinates x, y and z are obtained by taking the ratios of the tristimulus values
(X, Y and Z) to their sum:
x
X
X  Y  Z 
y
Y
X  Y  Z 
z
Z
X  Y  Z 
Another well-known way to present the color parameters a* and b* is by their hue angle (h*) and
Chroma (C*).
Hue angle is measured in degrees starting with h*=0 in the red direction (+a*) and increasing
counterclockwise:
h *  arctan
b*
a*
Chroma is defined as the length of the line from the point a*=b*=0 to the sample point:
C *  a *  b*
2
2
To describe color differences, a well-known parameter is ELab, which is defined as:
E Lab  (L*) 2  (a*) 2  (b*) 2
In which,
L*, a* and b* represent the difference in L*a*b* values between the reference color and the
actual measured L*a*b* values.
4.8.2
‘Home’ ribbon tab, ‘Channel’ Button
If the spectrometer system contains one or more slave spectrometer channels, the
spectrometer channel on which the color will be measured can be selected from the drop
down box that will appear after pressing this button. Make sure white reference and dark
spectra have been saved before for the selected spectrometer channel.
4.8.3
‘Home’ ribbon tab, ‘Edit’ Button
After selecting the ‘Edit’ button a form is displayed in which the input parameters can be
set. The dialog shows three tabbed pages: one is called “L*a*b*Chart Parameters” and shows
the input parameters for displaying the color measurements in a color chart; the second one
is called ‘Select Output File’, and the third one is called ‘Edit Reference Color’.
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4.8.3.1
L*a*b*Chart Parameters
The following parameters can be set before the measurements are started:
- Colorimetric Parameters. Select which parameters are to be calculated and shown in the
measurement.
- CIE Standard Observer. The original CIE standard observer functions x, y and z were
defined in 1931, and are known as the 2 degrees standard observer values. The 2 degrees
corresponds with the angle of vision that was used in the experiments to determine these
standard observer values. In 1964, the CIE recommended the use of different observer
values for a higher correlation with visual perception for large samples. These are known as
the 1964 supplementary standard observer, or 10 degrees observer values. Both standards
are still in use, and in AvaSoft, the CIE standard observer can be selected by clicking one of
the radiobuttons. The default is 2 degrees.
- Illuminant. The CIE Standard sources A, B or C or one of the illuminants D50, D55, D65 or
D75 can be selected by clicking one of the radio buttons. The default is D65, which is the
most widely used illuminant. It represents the power distribution of average daylight, with a
correlated color temperature of 6500K. The D50, D55 and D75 have correlated color
temperatures of 5000K, 5500K and 7500K. The CIE Standard sources A, B or C represent
respectively: Incandescent light (2854K blackbody), Simulated noon sunlight and Simulated
overcast sky daylight. Note that there is no relation between the illuminant chosen here and
the light source that is used for measuring the color of an object. The selected illuminant is
used in calculation of the color parameters. These color parameters will be different if for
example A will be selected instead of D65, just as the color of an object will look different
in average daylight or in incandescent light (2854K blackbody).
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4.8.3.2
Select Output File
The color parameters can be saved to an ASCII file during the measurements. The current name and
location of this ASCII file is shown under the ‘Select Output File’ tab. This filename (and path) can
be changed by clicking the “Change Output File” button. The next dialog will be displayed:
To start a new file for saving the color parameters, enter a filename that does not already exists
(AvaSoft will add the .txt extension), and click Open.
If an existing file is selected, the color parameters that will be saved are appended to this file. This
way experiments that were saved before can be proceeded, using the same output file.
4.8.3.3
Edit Reference Color
The reference color can be set to compare the L*, a* and b* color parameters during the online
measurements with the LREF, aREF and bREF of the reference color. The color differences can be
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shown during the measurements by dL (=L*-LREF), da (=a*-aREF), db (=b*-bREF) and/or dE
(= (dL2+da2+db2)).
The reference color can be entered manually under “Current Reference Color” in the figure above,
or it can be selected from a database file. The database file is a list of reference colors that were
saved before to this file, all with a unique ProductID. By default the name of the database file is
“empty.pct”. By clicking the DB button, a different database file can be selected, or a new file can
be created.
To start a new database file for saving reference colors, enter a filename that does not already
exists (AvaSoft will add the .pct extension), and click Open.
To open an existing file simply double click on the filename, or select it and click the Open button.
The file example.pct can be found in AvaSoft’s main directory and contains a few measured
reference colors.
To select a reference color from the database file, click the select button, below of the DB button.
The contents of the database file will be displayed as shown in the figure below:
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To select one of the products from the list, click on one of the numbers (1..11) in the first (gray)
column.
To delete a product from the list, select it and click the delete key on the keyboard.
To search for a certain productID or number, click the Find button.
To sort the records by ProductID, L-REF, a-REF or b-REF, click on the corresponding column header.
A yellow marked ‘1’ will be shown in the column header. By clicking again at the header which is
already marked, the sorting direction will be converted.
By clicking the Cancel button, the selected product will not be moved to the current reference color
in the LABChart settings dialog, and changes (e.g. deleting a product from the list) will be ignored.
By clicking the OK button, the current reference color in the LABChart settings dialog is changed to
the color which has been selected.
To add the current reference color (specified in the LABChart settings dialog) to the database file,
the Add button (below of the select button) can be clicked. If the ProductID already exists, a dialog
will be shown in which the choice can be made to overwrite the old color parameters with the new
ones, or to keep the old values for this productID. As an alternative, a reference color can be added
to the database during the online measurements. This can be done only if in the LABChart settings
dialog, the option “Add new reference colors to DB when measuring” is enabled.
The color measurements are started by clicking the OK button. AvaSoft returns to the main window
if the Cancel button is clicked.
4.8.4
‘Home’ ribbon tab, ‘Start/Stop’ Button
After all settings are filled in correctly the measurements can be started by clicking the ‘Start’
button. It might be easier to check the ‘follow main’ checkbox, in which case starting the
spectrometer measurements will also start the color measurements.
The figure below shows a measurement in progress.
The ‘Values’ panel shows a sample and reference color panel. Note that the displayed colors on the
monitor may not match the color of the object exactly (depends on monitor), but it will give a good
impression. Under the panels are tables of the values for measured color parameters and the
reference color values.
The ‘Settings’ panel shows the parameters that were set for this measurement.
The L*a*b*Chart panel shows a* and b* by a moving dot in a CIELAB graph.
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The measurements in the figure are performed with the spectrometer nr. 6105153VB channel and
illuminant D65 has been selected. The color parameters are calculated with the 2 degrees CIE
standard observer values.
The ‘Stop’ button is clicked to stop the color measurements.
4.8.5
‘Home’ ribbon tab, ‘Save Reference Color’ Button
The “Save Reference Color” button is used to update the current reference color. After
clicking this button, a dialog is displayed in which a name for the ProductID needs to be
entered. If the productID already exists in the database file and if the option “Add new
reference colors to DB when measuring” is enabled in the LabChart settings dialog, then a
dialog will be shown in which the choice can be made to overwrite the old color parameters
with the new ones, or to keep the old values for this productID (see the next figure).
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4.8.6
‘Home’ ribbon tab, ‘Pick Reference Color’ Button
The ‘Pick’ button can be used to select a new reference color from the database, as
described in detail on the previous page.
4.8.7
‘Home’ ribbon tab, ‘Save Col. Values’ Button
Each time the ‘Save Col. Values” button is clicked, a new record is added to the Filename in
the lower left corner. One record contains the following fields: Date, Time, Comments, L,
a, b, h, c, X, Y, Z, RefProductID, Lref, aRef, bRef, dL, da, db, dE, Channel, Illuminant and
Observer. The Comments field contains the text that is entered in the dialog that is shown
after clicking the Save button.
4.9 Irradiance
AvaSoft-IRRAD has been developed to perform on-line absolute irradiance measurements with an
Avantes spectrometer system. A calibrated light source AvaLight-HAL-CAL or AvaLight-DH-CAL with
known energy output (in µWatt/cm2/nm) is used as a reference. Also the calibration of an Avantes
spectrometer system can be done in our calibration lab, after which this calibration can be loaded.
Color of light parameters can be expressed by the chromaticity coordinated x, y and z. These
chromaticity coordinates are obtained by taking the ratios of the tristimulus values (X, Y and Z) to
their sum. The tristimulus values X, Y and Z and the spectral irradiance are computed in a
wavelength range from 380 nm to 780 nm, using a 1 nm interval. These parameters, as well as the
coordinates u, v and the color temperature of an external light source can be calculated and
displayed in real-time. For LED measurements, the Dominant Wavelength and Purity are interesting
parameters, which can be calculated as well. The Color Rendering Index (CRI) is a measure of the
color rendering properties of a light source.
The same experimental set up (spectrometer with fiber optics and cosine corrector or integrating
sphere) is used to calculate the photometric and/or radiometric parameters of the light to be
measured. The calculated output can be displayed and saved in three ways:
- In a Spectrum application window the data can be displayed as spectral irradiance in
µWatt/cm2/nm versus wavelength.
- The measurement results can also be displayed in an Irradiance application window (figure
above), which shows the chromaticity diagram and many parameters for colorimetry,
photometry, radiometry and peak measurements. Up to 10 different radiometric parameters
and/or wavelength ranges can be selected for which the output will be displayed.
- In a Time series application window, a function can be displayed simultaneously against
time. For each window, a different radiometric, photometric, color coordinate or peak
output parameter and/or wavelength range may be selected, as well as a different
spectrometer channel.
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4.9.1
Background
Before irradiance measurements can be done, an intensity calibration is required. The intensity
calibration contains the data transfer function for each pixel. The data transfer function is used to
convert the scope data (A/D Counts) into irradiance data (in µWatt/cm 2) . To be able to calculate
the transfer function, a calibrated light source, with known output (in µWatt/cm 2/nm) needs to be
available.
When saving the A/D Counts with the reference light source on and off, we know the relation
between the A/D Counts and µWatt/cm2:


Caldata n


 refcal n  darkcaln 
Caldatan
refcaln
darkcaln
= Intensity of the calibrated light source at pixel n (in µWatt/cm 2) from lamp file
= A/D Counts at pixel n that were saved with the reference light source on
= A/D Counts at pixel n that were saved with the reference light source off
When measuring the A/D counts received from a light source different from the calibrated light
source (but of course with the same fiber optic cable and diffuser), this relation can be used to
measure the intensity at every pixel n (in µWatt/cm 2). If samplen is the measured A/D counts at
pixel n when looking at the sample light source, and dark n is the measured A/D Counts with the
sample light source off, then the equation for intensity I n (in µWatt/cm2) becomes:
 samplen  darkn 

I n  Caldata n * 
 refcal n  darkcaln 
If during the intensity calibration an integration time was used (e.g. 100ms) that differs from the
integration time during the sample measurements (e.g. 2 ms), a factor needs to be added to the
equation to compensate for the difference. In the example the factor is 100/2 = 50.
Calculating the intensity (in µWatt/cm 2) from the measured sample spectrum (in A/D Counts) can
therefore be done by the following equation:
 samplen  dark n 
 * factor
I n  Caldata n * 
 refcal n  darkcaln 
From the irradiance spectrum (in µWatt/cm2), a lot of light output parameters can be calculated:
colorimetric, photometric and radiometric.
Below, short background information is given about the colorimetric, radiometric and photometric
parameters. We also describe the definition of the peak parameters that can be measured as well.
Colorimetry
The color of light can be expressed by the chromaticity coordinates x, y and z. These chromaticity
coordinates are obtained by taking the ratios of the tristimulus values (X, Y and Z) to their sum:
x
X
X  Y  Z 
y
Y
X  Y  Z 
z
Z
X  Y  Z 
The tristimulus values X, Y and Z are computed by:
X  k *  I  * x
Y  k *  I  * y
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where:
k
I
x, y , z 
wavelength 
=
=
=
constant (= 1/(y ) = 0.00934
Spectral irradiance at wavelength 
CIE 1931 or 1964 Standard Observer value (2 or 10 degrees angle) at
The tristimulus values X, Y and Z and the spectral irradiance are computed in a wavelength range
from 380 nm to 780 nm, using a 1 nm interval.
The CIE1960 UCS color coordinates u and v are calculated by:
u
4x
 2 x  12 y  3
v
6y
 2 x  12 y  3
The equation that is used for calculating the color temperature is empirical and assumes a black
body radiator:
p = ((x-0.332)/(y-0.1858))
Color Temp =5520.33-(6823.3*p)+(3525*p2)-(449*p3)
The Color Rendering Index (CRI) is a measure of the color rendering properties of a light source.
The CIE has defined 14 standard color samples and the CRI Ra is defined as the mean value of the
color rendering values of the first 8 R values of these standard CIE samples.
A CRI Ra of 100 indicates that the sample sources have identical color coordinates under the light
source to be tested and the reference light source. A CRI Ra value of 50 is assigned to the CIE
standard warm white fluorescent lamp.
The CRI calculation method used is based on the CIE 13.3-1995 standard.
A reference light source is calculated on the basis of the color temperature of the light source to be
tested. The color temperature calculation is done with the McCamy algorithm described above.
For color temperatures under 5000K, a standard Planckian radiator is calculated with a color
temperature that equals the color temperature of the sample light source. For color temperatures
between 5000K and 25000K, a standard daylight distribution is calculated, again with an identical
color temperature.
The 14 standard CIE samples are then ‘illuminated’ with both light sources, and from the difference
in chromaticity values the 14 Special Rendering Indices are calculated, the first 8 of which yield the
CRI.
You can calculate both the general Ra, or any one of the 14 separate R values.
A more recent development is the Color Quality Scale (CQS), proposed by the NIST. It addresses
some of the limitations that are present in the CRI, e.g. by using a larger set of samples, all of high
chroma, by using a better chromatic adaptation transform and by avoiding negative score values.
The version of the CQS that is implemented in AvaSoft is version 9.0.1.
The 15 standard CQS samples are again ‘illuminated’ with the light source to be tested and a
calculated reference light source. An rms calculation on all 15 samples yields the general CQS Qa
value.
You can choose to calculate both the general Qa, or any one of the 15 separate Q values.
In LED measurements, the Dominant Wavelength and Purity (also known as HelmHoltz coordinates)
are often used to describe a color. The Dominant Wavelength can be calculated for a measured
sample point S with chromaticity coordinates (Sx,Sy) by drawing a straight line from the midpoint in
the chromaticity diagram (E with x=y=0.333) through S towards the edge of the Chromaticity
Diagram (spectrum locus). The points at the spectrum locus correspond with a wavelength and the
interception of the straight line through E and S with the locus is called the Dominant Wavelength.
Purity, is the distance from the midpoint (E) to the sample point (S), divided by that from the
midpoint (E) to the spectrum locus (DW):
Purity = (E-S) / (E-DW)
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The method described above is used for all colors with a Dominant Wavelength from 380 to 699
nanometres. If the x,y coordinates are in the triangle area encompassed by the 3 points E, A and B,
then the Dominant Wavelength cannot be calculated because the interception point through E and
S with the spectrum locus (between A and B) does not correspond with a wavelength. In that case
the Complementary Dominant Wavelength (CDW) is used. The line from E through S is extended
backward in order to determine the Complementary Dominant Wavelength (CDW).
Radiometry
The radiometric parameters can be grouped into three categories:
- Radiant Flux [µWatt]: The radiant flux is the total optical power emitted from a source in all
directions. The best way to measure the power emitted by a source is to measure the
source inside an integrating sphere. This is often done when measuring LED’s. It is also
possible to calculate the flux of a source by measuring the irradiance at the surface of the
diffuser (cosine corrector or integrating sphere sample port) at a certain distance from a
light source. An important assumption in this calculation is that the source should be
isotropic and the distance between diffuser and source should be greater than five times
the largest dimension of the source (approximation of point source).
- Radiant Intensity [µWatt/sr]: The radiant intensity is the optical power per unit solid angle.
It is used to quantify the optical power that is emitted by a source into a certain direction.
Radiant intensity is calculated from the measured irradiance by multiplication with the
square of the distance between source and diffuser surface. It is assumed that the source is
a point source.
- Irradiance [µWatt/cm2]: Irradiance is used to measure the power that is received by a
surface.
Radiometric measurement can be done in different setups, like with fiber optic cosine corrector or
integrating sphere. Both setups can be used to measure the irradiance spectrum received at the
surface of the diffuser (cosine corrector or integrating sphere sample port) at a certain distance
from a light source. When measuring at a certain distance from the source, the radiant intensity and
flux can be calculated as described above. When measuring a light source inside an integrating
sphere, the radiant flux can be measured, but radiant intensity and irradiance parameters cannot
be measured.
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Radiometric parameters calculated from the power distribution
The power distribution can be easily converted in an energy distribution by multiplying the power
with the integration time. The result is the amount of energy that has been emitted or received
during one integration time cycle.
Another radiometric parameter that can be calculated from the irradiance spectrum, is the number
of photons that is received by a surface. Since the number of photons per nanometer is a huge
number (even with very low light intensity), the number of Avogadro is used to express the number
of photons in mols, or as in our application in μmols. The number of photons per nanometer can be
calculated from the wavelength dependent photon energy, and the absolute light energy that is
measured. A detailed description how this is done can be found at the next page.
The photon count distribution [µMol/(s.m2.nm)] shows the photon flux received per square meter.
Other photon count units that can be calculated from this are:
- [µMol/(s.nm)] photon flux received at diffuser surface
- [µMol/( m2.nm)]
photons received per square meter during one integration cycle
- [µMol/nm]
photons received at diffuser surface during one integration cycle
How to convert a power distribution [µWatt/(cm2.nm)] into a photon count distribution
[µMol/(s.m2.nm)]
Photon energy E() = h.c/ e
Where:
h = Planck´s constant 6,626 068 76 x10 -34
c = velocity of light 2,998 x108 m/s
 = wavelength in meters
For example, the photon energy at 250 nm and at 1000 nm is:
E(250) = (6,626 x 10-34. 2,998 x 108)/ 250.10-9 = 7,946 x10-19 (Joule/photon)
E(1000)= (6,626 x 10-34. 2,998 x 108)/ 1000.10-9 = 1,986 x10-19 (Joule/photon)
(1)
(2)
1eV = 1,60207 x 10-19 Joule, so the photon energy expressed in eV/photon becomes:
E(250) = 7,946 x10-19 /1,60207 x 10-19 = 4,9592 (eV/photon)
E(1000)= 1,986 x10-19 /1,60207 x 10-19 = 1,2398 (eV/photon)
(3)
(4)
Suppose we measure 20 Watt/cm2 at a certain wavelength
20 Watt/cm2 = 20 Joule/s/cm2 = 0.2 Joule/s/m2
= 0.2/(1,60207 x 10-19 ) eV/s/m2
= 1,248 . 1018 eV/s/m2
(5)
Knowing the photon energy at 250 nm and at 1000 nm from (3) and (4), the number of photons
that correspond with 20 Watt/cm2 at 250 nm and at 1000 nm can be calculated from (5) by:
for 250 nm
for 1000 nm
: #photons = 1,248 . 1018 / 4,9592 = 2,517 . 1017 photons/s/m2
: #photons = 1,248 . 1018 / 1,2398 = 1,007 . 1018 photons/s/m2
With 1 mol = 6,02308 x1023 (Number of Avogadro)
1 mol = 6,02308 x1017
So, the number of photons, expressed in mol/s/m2, when measuring 20 Watt/cm2 at
wavelength 250 nm and also 20 Watt/cm2 at 1000 nm becomes:
for 250 nm
: 2,517 . 1017 / 6,02308 .1017 = 0,418 mol/s/m2
for 1000 nm
: 1,007 . 1018 / 6,02308 .1017 = 1,672 mol/s/m2
.
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In the table below, the radiometric parameters that can be measured in AvaSoft are listed. Note
that a wavelength range needs to be specified over which the parameter spectral output will be
integrated. In the first column (Hardware setup), “inside sphere” refers to measurements that are
done with the light source inside an integrating sphere, while “outside sphere or cc” refers to
measurements that are done with a light source at a certain distance from the sphere or with a
cosine corrector
Hardware Setup
Parameter
Unit
Description
inside sphere
Radiant Flux
(Power emitted)
µWatt
Total optical power emitted from a source
inside sphere
Energy emitted
µJoule
Total optical energy emitted from a source,
calculated by multiplication of the power with
the integration time
outside sphere or cc
Radiant Flux
(Power emitted)
µWatt
Total optical power emitted from a source,
calculated by multiplication of radiant intensity
with the solid angle of the light source
outside sphere or cc
Energy emitted
µJoule
Total optical energy emitted from a source,
calculated by multiplication of the power with
the integration time
outside sphere or cc
Radiant Intensity µWatt/sr
Optical power per unit solid angle, calculated by
multiplication of irradiance with the square
distance between point source and diffuser
surface
outside sphere or cc
Radiant Energy
µJoule/sr
Total optical energy emitted from a source,
calculated by multiplication of the radiant
intensity with the integration time
outside sphere or cc
Power received
µWatt
Power received at diffuser surface
outside sphere or cc
Energy received
µJoule
Energy received at diffuser surface, calculated
by multiplication of the power with the
integration time
outside sphere or cc
Irradiance
µWatt/cm2
2
µJoule/cm
2
Power received per square centimeter
outside sphere or cc
Energy/cm
outside sphere or cc
Photon Flux/m2
µMol/(s.m2)
Photons received per second and per square
meter, see for calculation previous page
outside sphere or cc
Photon Flux
µMol/s
Photons received per second at diffuser surface
outside sphere or cc
Photons/m
2
outside sphere or cc
Photons
µMol/m
µMol
2
Energy received per square centimeter,
calculated by multiplication of irradiance with
the integration time
Photons received per square meter during one
integration time cycle
Photons received at diffuser surface during one
integration time cycle
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Photometry
Photometry is the measurement of visible light. Unlike radiometry, it is not a purely physical
measurement and is calculated considering a 'standard' human visual perception. This is attained by
multiplying the radiometric data by the luminous efficacy curve (see figure above) and integrating
the product over the visible range (380 – 780 nm).
The three categories that were defined for the radiometric parameters can also be used for the
photometric parameters.
The photometric equivalent for the Radiant Flux [µWatt] is the Luminous Flux, expressed in Lumens.
The photometric equivalent for the Radiant Intensity [µWatt/sr] is the Luminous Intensity,
expressed in Lumens/sr. This unit is equal to Candela.
The photometric equivalent for Irradiance [µWatt/cm 2] is called Illuminance, expressed in
Lumens/m2. This unit is equal to Lux.
Since the geometry of the three categories is the same for radiometry and photometry, the same
can be written about the hardware setup: luminous flux can be measured inside an integrating
sphere. When measuring a source at a certain distance from the integrating sphere or cosine
corrector, the luminous flux can be calculated, assuming that the source is an isotropic point
source. The Luminous Intensity [Candela] and Illuminance [Lux] of a sphere can be measured
outside the integrating sphere or with a cosine corrector.
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Peak Measurements
A peak from a fluorescent lamp is shown in the figure below. A number of peak parameters can be
calculated from this spectrum:
FWHM and Center Wavelength
The Full Width Half Maximum of a peak is the bandwidth (in nanometers) for which the intensity is
higher than half of the maximum intensity of that peak. The Center Wavelength is the wavelength
halfway between the left and right wavelength where the intensity is half of the maximum
intensity.
Peak Wavelength
Wavelength at the maximum spectral power
Centroid Wavelength
The total spectral power left and right from the centroid wavelength (integral) is the same.
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4.9.2
Quick Start
Quick Start (1): Perform absolute irradiance measurements using a calibrated lamp
Start the AvaSoft software, and click the Start button in the main window.
Connect a fiber to the Spectrometer input port.
Click the “Settings” button in the correct spectrometer window and select the “Irradiance” tab.
Click the “Perform Intensity Calibration” button.
Select the calibration lamp file and enter the diameter of the fiber/cosine corrector or integrating
sphere sample port that is used, as described in section 3.9.4.
Turn on the reference light source (e.g. AvaLight-HAL-CAL or AvaLight-HAL-CAL-ISP). If a cosine
corrector is used at the end of the fiber, mount it directly on the reference light source. If an
integrating sphere is used at the end of the fiber, put the integrating sphere sample port over the
light output port.
Verify that the calibration lamp is ON for at least 15 minutes, and click the “Start Intensity
Calibration” button. Try to adjust the integration time while looking at the reference light, such
that the maximum count over the wavelength range is around 90% of the full ADC scale, which is
59000 counts for the 16bit ADC. It’s also possible to let AvaSoft search for an optimal integration
time by clicking the ‘AC’ button.
Adjust the Smoothing Parameter to optimize smoothing for the Fiber/Slit diameter that is used.
If a good reference signal is displayed, click the bright lightbulb “Save Reference” button. A white
line will mark the reference spectrum. Then switch off the calibration lamp, wait until the spectrum
becomes flat, near the bottom of the scale, and click the dark lightbulb button to save a dark
spectrum. A black line will mark the dark spectrum.
Click the “Save Intensity Calibration” button. A dialog shows up in which the current settings in this
intensity calibration are shown. If the calibration has been performed with diffuser, the intensity
calibration data will be saved to an ASCII file with extension *.dfr, with bare fiber this extension will
be *.fbr. The name of the intensity calibration file can be entered after clicking the “Save As”
button. With USB2 spectrometers, the intensity calibration can also be saved to EEProm by clicking
the “Save to EEProm” button. Click the Close button to Close the dialog.
Open an Irradiance application window to select the colorimetric, radiometric, photometric and/or
peak parameters of interest (see section 3.9.5) . Then click OK.
Measure the output parameters in the experiment. If needed, change the integration time, such
that the maximum in Scope Mode is around 90% of the full ADC scale, which is 59000 counts for the
16bit ADC). Block the light path to the spectrometer, and save a dark spectrum. If the (ir)radiance
of the light to be measured needs to be displayed against time, open a Time series application
window and select an Irradiance function as described in section 3.6.
The intensity calibration as performed under point 9 can be loaded in future experiments by
selecting the option “Load Intensity Calibration”, as described below under Quick Start (2). For the
USB2 spectrometers, the intensity calibration that has been stored in the EEProm is loaded
automatically during the initialization of AvaSoft. After loading an intensity calibration, a dark
spectrum needs to be saved before switching to Irradiance mode.
Quick Start (2): Perform absolute irradiance measurements by loading an intensity calibration
Start the AvaSoft software, and click the Start button in the main window.
Connect the same fiber (and diffuser or integrating sphere) that was used during the intensity
calibration that will be loaded to the Spectrometer input port.
Click the “Settings” button in the correct spectrometer window and select the “Irradiance” tab. If
an intensity calibration has been stored in eeprom before, this will be autoloaded at AvaSoft
program initialization. Click the “Load from File” button. A dialog shows up in which the intensity
calibration file can be selected. Select the file and click the open button.
Open an Irradiance application window and select the colorimetric, radiometric, photometric
and/or peak parameters of interest (see section 3.9.5.2) . Then click OK.
Measure the output parameters in the experiment. If needed, change the integration time, such
that the maximum in Scope Mode is around 90% of the full ADC scale (59000 counts for the 16bit
ADC). Block the light path to the spectrometer, and save a dark spectrum. If the (ir)radiance of the
light to be measured needs to be displayed against time, open a Time series application window and
select an Irradiance function as described in section 3.6.
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4.9.3
Load Intensity Calibration
By selecting the Spectrometer Settings button in the spectrometer windows, and then selecting the
Irradiance tab, a window is shown in which the intensity calibration that was saved before can be
loaded by clicking the “Load from File” button.
An intensity calibration file contains the data which is necessary to convert the Scope data to
Irradiance data. If the spectrometer system has one or more slave channels, it is important to know
that the calibration data for each spectrometer channel are saved in a separate file. To measure
irradiance data at more spectrometer channels simultaneously, the calibration files for each
spectrometer channels need to be loaded first. After loading an intensity calibration file, a graph is
displayed which shows the data transfer function for the loaded channel. The irradiance spectrum is
calculated by multiplying the measured scope data (from which a saved dark spectrum is
subtracted) with this data transfer function.
The intensity calibration is loaded from eeprom by default. However, if multiple calibrations are
available for a spectrometer, the eeprom calibration can be overruled by loading a calibration from
file. The filename that holds the intensity calibration needs to include the serial number of the
spectrometer channel.
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4.9.4
Perform Intensity Calibration
If a calibrated light source such as the AvaLight-HAL-CAL or AvaLight-DH-CAL is available, an
intensity calibration can be performed. The Irradiance tab contains a “Perform Intensity
Calibration” field. The following settings need to be entered before starting the intensity
calibration:
- Calibration Lampfile
- CC-UV/VIS, Fiber or AvaSphere sample port diameter
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Calibration Lamp
The energy output (in µWatt/cm2/nm) for the calibration lamp that will be used can be found in a
file with the extension *.lmp. This file needs to be selected by clicking the “Select” button.
After the calibration file has been selected, the data can be viewed, edited and/or saved under a
different filename by clicking the “View/Edit Lamp Calibration Data” button.
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A dialog with the intensity versus wavelength values for the selected calibration light source is
shown, as well as a graph in which the intensity is displayed versus wavelength:
If needed, the data can be edited and saved under another filename by clicking the Save As…
button. Before the changed data takes effect, the new filename needs to be loaded with the Select
lamp option described above.
CC-UV/VIS, Fiber or AvaSphere sample port diameter
The hardware setup for which the calibration lamp has been calibrated (CC-UV/VIS cosine corrector,
bare fiber or integrating sphere), should match the hardware setup that is used during the intensity
calibration. The diameter of the cosine corrector (3900 micron), bare fiber, or AvaSphere (6000,
10000 or 15000 micron for respectively AvaSphere-30, AvaSphere-50 and AvaSphere-80) needs to be
entered in micron.
It is important that the hardware setup that is used during the calibration, is the same as the
hardware setup in the (ir)radiance measurements.
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4.9.4.1
Start Intensity Calibration
Verify that the calibration is ON for at least 15 minutes, and that the hardware has been setup
correctly. Then click the button “Start Calibration”. As a result, the Scope data (A/D Counts) for the
selected spectrometer channel will be displayed graphically.
Set the smoothing parameter to optimize smoothing for the fiber/slit diameter used (see also
section Measurements Settings).
Set the integration time such that a good reference signal is measured (maximum around 90% of the
full ADC scale, which is 59000 counts for the 16bit ADC). It’s also possible to let AvaSoft search for
an optimal integration time by clicking the AutoConfigure Integration time (‘AC’) button.
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Set the Number of Averages to a high number to reduce the noise during the intensity calibration.
If a good reference signal is displayed, click the bright bulb button in the dialog above. A white line
will mark the reference spectrum. Then switch off the calibration lamp, wait until the spectrum
becomes flat, near the bottom of the scale, and click the dark bulb button to save a dark spectrum.
A black line will mark the dark spectrum.
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4.9.4.2
Save Intensity Calibration
If reference and dark data have been saved in the figure above, the intensity calibration can be
saved by clicking the “Save Calibration” button.
A dialog shows up in which the current settings in this intensity calibration are shown. If the
calibration has been performed with diffuser, the intensity calibration data will be saved to an ASCII
file with extension *.dfr, with bare fiber this extension will be *.fbr. The name of the intensity
calibration file can be entered after clicking the “Save To File As…” button. When saving an
intensity calibration to file, make sure to include the serial number in the filename.
The following data will be saved to the intensity calibration file:
- The name of light source calibration file (*.lmp)
- The number of pixels
- The integration time in milliseconds
- The diameter of diffuser surface in microns
- A value per pixel, which represent the dynamic range (reference minus dark data) at each
pixel during the intensity calibration, divided by the intensity of the calibrated light source
that was used.
- The setting for the Smoothing parameter during the intensity calibration.
By pressing the “Save to EEPROM” button, the calibration will be saved to the AvaSpec itself.
After an intensity calibration has been performed, a graph is displayed which shows the data
transfer function for the spectrometer channel. The irradiance spectrum is calculated by
multiplying the measured scope data (from which a saved dark spectrum is subtracted) with this
data transfer function.
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4.9.5
Irradiance Application Window
4.9.5.1
‘Home’ ribbon tab, ‘Channel’ Button
4.9.5.2
‘Home’ ribbon tab, ‘Settings’ Button
After clicking the ‘Settings’ button, you can select the parameters that will be shown in the
irradiance chart. They are distributed over 4 tab sheets, one for each kind of measurement. A
description of these parameters and how they are calculated can be found in section Background
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Colorimetric parameters
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Radiometric parameters
An important assumption when calculating the emitted power or energy is that the source should be
an isotropic point source.
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Photometric parameters
An important assumption is that the source should be an isotropic point source.
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Peak Measurement parameters
4.9.5.3
‘Home’ ribbon tab, ‘Start/Stop’ Button
After all settings are filled in correctly the measurements can be started by clicking the ‘Start’
button. It might be easier to check the ‘follow main’ checkbox, in which case starting the
spectrometer measurements will also start the irradiance measurements.
The figure below shows a measurement in progress.
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The chromaticity diagram is used to visualize the colorimetric measurements. Depending on what
has been selected in the irradiance chart settings dialog, it will display the locus for the 2 or 10
degrees standard observer. The measured (x,y) coordinates will be displayed in the diagram and a
line will be drawn from the midpoint (x=y=1/3) through the measured (x,y) to the edge of the locus,
which represents the dominant wavelength. If you mouse over the black dots on the edge of the
locus, the wavelength corresponding to the dot will be displayed in a small popup help window.
The ‘Stop’ button is clicked to stop the color measurements.
4.9.5.4
‘Home’ ribbon tab, ‘Open Spectral Data’ Button
4.9.5.5
‘Home’ ribbon tab, ‘Save Spectral Data’ Button
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4.10
4.10.1
Thin Film
Film Thickness Primer
As light is reflected from both sides of a transparent thin film on a reflective surface, an
interference spectrum is formed. This spectrum looks generally like a sine wave with a frequency
that decreases with the wavelength (a ‘chirp’). The thickness of the layer determines the frequency
of the sine wave at a given wavelength, where a larger thickness will render a higher frequency (i.e.
more waves visible).
This means that you can determine the thickness of a layer by either determining the frequency of
these sine waves directly from the measured spectrum (through Fast Fourier calculations), or by
calculating a theoretical spectrum for lots of different values for thickness, and matching these
spectra with the measured one, yielding the best fit as the measured thickness.
Both methods are available in the AvaSoft Thin Film application.
The FFT algorithm can be used if the range to be searched is too large to be calculated in a
reasonable amount of time with the “Match Spectrum” algorithm, or if the materials are not well
defined. The finish of some materials (“roughness”) can influence the reflectance values
considerably.
The “Match Spectrum” algorithm is the default one. It is most suited for thin layers of well defined
materials, e.g. those used on silicon wafers.
The “Match Spectrum” algorithm has a zooming feature that will speed up readings considerably.
A running range is kept from the last 10 values of the Fit Quality value. This value is used as a
marker for a stable measurement. If this value drops below a defined level, then the theoretical
spectra will not be calculated for the full range between the lower and upper limit. They will only
be calculated for a limited range of steps, above and below the current thickness measurement
value. A single value above the defined level (meaning the fit is not that good anymore) will undo
the zoom, and the full range will be calculated again.
For thin layers, the lower end of the wavelength spectrum will limit the precision with which thin
layers can be measured. Very thin layers will yield only part of a single sine. The wavelength range
from 200-400 nm can be very important in this case.
For thick layers, the resolution of the spectrometer will be the limiting factor in the measurement,
as the sine waves will start to fuse together. The upper end of the wavelength spectrum will yield
the best results in this case, as the frequency of the sine waves becomes larger with decreasing
wavelength.
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These effects are illustrated in the following figures that show theoretical reflectance spectra for
SiO2 layers on Si with a thickness of respectively 10 nm, 500 nm, 5000 nm and 50000 nm.
The wavelength range is 200 – 1100 nm in all four figures.
10 nm
500 nm
5000
50000nm
4.10.2 Quick Start: Measuring and saving a Reflectance spectrum and a Film
Thickness
1. After starting AvaSoft, the Start button needs to be clicked to start measuring.
2. Connect the reflectance probe to the light source and to the spectrometer input port(s) and
set up the experiment for taking a reference spectrum. The reference spectrum should be
taken from the uncoated substrate material.
3. Select the Thinfilm application in the Applications toolbar.
4. Select Settings and enter correct values for wavelength limits, materials and thickness limits
under the Measurement Settings Tab. Select an algorithm under the Calculation options tab.
Press ‘Done’ to save.
5. Now turn on the light source. Usually some sort of spectrum may be seen on the screen, but
it is possible that too much or too little light reaches the spectrometer at the present data
collection settings. This amount of light is controlled by the integration time. Select the
AutoConfigure button “AC” in the spectrometer window. The integration time can also be
changed manually as described in section 3.3.3.1 (Measurement Settings).
6. Now turn off the light source and save the Dark data. This is done by pressing the dark bulb
icon in the spectrometer window. Always Save Dark after the integration time has been
changed.
7. Turn on the light source again. Save the present spectrum as a reference by pressing the lit
bulb icon in the spectrometer window (next to the black one). Always use Save Reference
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after the integration time has been changed. After saving a reference, replace the
reference material by the coated material. Verify that with the coated material, the
maximum value of the signal is not overloading the spectrometer. In most cases this will not
be the case as the coating will absorb part of the light, but for some coatings the light of
the coated material will reflect more than uncoated reference material. If this is the case,
a new reference and dark spectrum should be taken at a lower integration time at which
the coated material will not overload the spectrometer.
8. Click the reflectance (R) button to switch to reflectance mode. This will also start the Film
Thickness measurements, displayed in the Values panel. By clicking the stop button in the
top left corner, the data acquisition is stopped and the last acquired spectrum is shown in
static mode. The data acquisition can be started again by clicking the same button, which
now shows ‘Start’.
9. To save the spectrum, select the ‘Spectrum 1’ application, which allows you to save the
spectrum in Scope mode or in Reflectance mode. You can export or print the chart in the
‘Graph’ ribbon tab.
10. To improve the Signal/Noise ratio, a number of spectra may be averaged. To do this, the
Averaging value in the spectrometer window (below the integration time) can be increased.
4.10.3
Thin Film Application Window
The upper left ‘Values’ panel contains the large type Thickness and Fit Quality fields. These fields
are read-only. The Fit Quality is defined as the square root of the average SSR (sum of squared
residuals), when comparing a theoretical spectrum with a measured spectrum. The reflectance
values are normalized first by dividing them through the calculated reference reflectance.
The middle left ‘Properties’ panel contains either a display of the settings that can be edited in the
‘Settings’ dialog, or it shows the Variance Graph. You can switch between these displays by pressing
the ‘Show/Hide’ button.
The upper right panel contains a chart of the Thinfilm spectrum in either Scope mode or
Reflectance mode .
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The bottom panel (not shown in the figure above) contains the Thinfilm time series chart. Resize
the window to show or hide this part of the window.
4.10.3.1
‘Home’ ribbon tab, ‘Channel’ Button
Allows you to select the spectrometer channel used.
4.10.3.2
‘Home’ ribbon tab, ‘Settings’ Button
After clicking the ‘Settings’ button, you can select the parameters that will be used in the
thin film application. They are distributed over 3 tab sheets:
-
Measurement Settings
The wavelength limits used in the calculations can be edited in the two input fields on the top line.
Default values here will reflect the full range of the spectrometer channel. Be sure to view the
Reflectance spectrum and limit the range here accordingly. Without a UV light source, you should
set the lower limit to about 400 nm, as the Reflectance spectrum will only contain bogus noise
information at very low signal values.
The next three edit fields show the filenames for the .nk files used. The default values are for a
SiO2 coating layer on a Si substrate.
Normally, you should enter the same filename for Reference and Substrate. To do this, you can also
uncheck the ‘Use Alternate Substrate’ checkbox. The Reference field is available to enable use of a
different (uncoated) reference material, in case the substrate material is not available in an
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uncoated state. You can change the values for the filenames by clicking the button to the right of
each field.
You will then enter a File Open Dialog, that allows you to select an .nk file for many predefined
materials.
The lower and upper thickness limit values can be edited in the Thickness fields in the lower part of
the form. If you are confident about the layer thickness, select a narrow range here. This will
significantly speed up your measurement in the default Match Spectrum mode, as it will limit the
amount of spectra that are calculated for each reading.
The buttons at the bottom of the Layer Display window allow you to Save and Load the menu
settings. The ‘Done’ button will also save the values entered, and the information saved will be
reloaded in the next session.
The ‘Load’ and ‘Save As’ buttons allow you to save the same information to a different filename
(‘*.tf.ini’) in the user directory, and reload it at a later time.
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Calculation Options
The top of this form allows you to select which algorithm is used to calculate thickness values. The
default value is ‘Match Spectrum’, which is suited best for thin layers of well defined materials.
The ‘FFT Model’ algorithm is suited best for thick layers, and for materials where roughness of the
material influences the reflectance value.
The lower part of the form only applies to the ‘Match Spectrum’ algorithm.
The ‘Thickness Step Size’ value determines the interval between the lower and upper thickness
limits at which the theoretical reflectance spectrum will be evaluated against the measured
reflectance spectrum during the first (global) search. The default step size is 4 nm. By decreasing
this value, more theoretical spectra will be evaluated during the first step in the algorithm. This
will take more time, but it can also increase the certainty of finding the best solution.
The graph below shows the quality of fit at the Y-axis against the evaluated layer thickness at the Xaxis. In this example the thickness limits were set to 0 nm and 1000 nm, as shown at the X-axis.
With a 4 nm step size this means that 251 spectra are evaluated in the first run. From the shape of
the curve can be concluded that it is very likely that the best thickness found (= minimum at 277
nm) is the optimum. Decreasing the thickness step size will therefore not give a higher certainty for
this material. You can also choose to take larger steps here to speed up calculations. It is of course
also possible to miss an optimum if this value is set too high.
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The 4 nm step size has been tested on a lot of different materials and leads to the right optimum in
all tests. The graph above is called the response curve and is available in the ThinFilm application
to get an impression about the robustness of the solution that was found. A detailed description
about this feature can be found below.
The ‘Fit Warning Level’ can be changed if the default warning level is not correct for your setup. If
the ‘Fit Quality’ value exceeds this warning level, the ’Fit Quality’ field in the Values panel will be
colored red.
The next two fields, ‘Narrow Search Steps’ and ‘Narrow Search Boundary’, allow you to fine-tune
the zooming feature that is part of the ‘Match Spectrum’ algorithm. A running range is kept from
the last 10 values of the Fit Quality value. This value is used as a marker for a stable measurement.
If this value drops below the ‘Narrow Search Boundary’, then the theoretical spectra will not be
calculated for the full range between the lower and upper limit in the Layer Display window. They
will only be calculated for a limited range of steps, above and below the current thickness
measurement value. The thickness range of steps is the product of the ‘Thickness Step Size’ and the
‘Narrow Search Steps’, both under and over the currently measured thickness value.
A single running range value that is over the limit will undo the zoom effect, and the full range will
be calculated again. After at least 10 readings, the algorithm can zoom in again.
If you press the ‘Show’ button, the Properties display will show a graph of the fit quality against
layer thickness.
This allows you to monitor whether there are more optima present in your range. You can also finetune the zooming feature here. The Narrow and Wide buttons force the algorithm to zoom in or out.
The ‘Value’ is the running range value, which is the absolute range in the last 10 values of the ‘Fit
Quality’ value.
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Time Series
This form allows you to set options for a time series measurement.
Check ‘Record measurement’ to chart either thickness or variance against time. The chart will be
displayed below the Thinfilm spectrum. You may have to expand the form to view it.
You can customize both x and y axis values.
You can also log values to disk, and change filename and logging frequency in the bottom part of
the form.
4.10.3.3
‘Home’ ribbon tab, ‘Start/Stop’ Button
After all settings are filled in correctly the measurements can be started by clicking the ‘Start’
button. It might be easier to check the ‘follow main’ checkbox, in which case starting the
spectrometer measurements will also start the thinfilm measurements.
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4.10.3.4
‘Home’ ribbon tab, Mode Selection buttons
This mode will show a real time raw data signal, with on the Y-axis the read out of the ADconverter and on the X-axis the calculated wavelength.
In Reflectance Mode, the reflectance at pixel n is calculated using the current sample,
reference and dark data sets in the following equation:
 samplen  dark n
Rn  100 * 
 ref n  dark n
4.10.3.5



‘Home’ ribbon tab, Edit/View .nk files
An example of a .nk file with a full list of n and k values being edited
.NK files hold the information about the n-value (real part of complex refractive index) and k-value
(extinction coefficient) of a material, as a function of the wavelength.
These values can be listed in two different ways.
The first, and most accurate way to list them is as a table (mostly from 150 to 1100 nm) with the n
and k value listed for each wavelength, with 1 nm increments for the wavelength.
The second way is with 6 coefficients, the so-called Cauchy coefficients. These allow the n and k
value to be calculated for each wavelength. The latter way is less accurate, but is the only one
available for many materials.
The ThinFilm application can edit both types of file. You can edit either the Cauchy values, or the n
and k values per wavelength. You can evaluate the resultant n and k values in the graph. Press
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‘Update Graph’ after a change, to view your changes. The ‘Save’ button allows you to save the .nk
file. Click the ‘Close’ button to leave without saving.
An example of a .nk file with Cauchy coefficients being edited
You might want to change a .nk file with Cauchy values to one with a full list of n and k values, in
order to fine-tune the values without bothering with the Cauchy formula. The ‘Expand Cauchy’
button allows you to do just that. Load an unexpanded .nk file (with Cauchy values) and save it in
an expanded form (without Cauchy values, but with a full list of n and k values).
The format of the .nk tables in the database are rather strict in their layout (wavelength numbers
should be incremented with 1 nanometer, starting at 150nm and ending at 1100nm. Also the
decimal separator and column separator should be respectively a period (.) and comma (,).
Moreover, the first 4 lines in the .nk file are reserved for respectively title, fixed wavelength,
wavelength range and cauchy coefficients.
The button “Convert TXT to NK” has been added to allow an easy import of custom specific
materials with known .nk tables. The data in the textfile (.txt extension) should hold 3 columns:
wavelength, n-value, k-value. The wavelength incrementation is not restricted, linear interpolation
will be used to convert the .txt file to a .nk file. The decimal separator can be a period (.) or
comma (,) and the column separator a space, tab, semicolon or other character(s).
After clicking the button, you will be asked to select a .txt that should be converted to the .nk
format.
After the conversion, the .nk file can be displayed/edited with the “Edit .NK File” menu option and
selected in the settings form.
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4.10.3.6
‘Graph’ ribbon tab, ‘Export Spectum Chart’ Button
Pull down menu:
- Windows Bitmap (*.bmp)
- Compressed Bitmap (*.jpg)
- Portable Network Graphics (*.png)
- Acrobat Reader (*.pdf)
Exports the Spectrum Chart to a choice of formats.
4.10.3.7
‘Graph’ ribbon tab, ‘ASCII’ Button
Exports the Spectrum Chart to ASCII text file with colums:
wavelength; calc-reflection; reflection at zero thickness; reflection-data
4.10.3.8
‘Graph’ ribbon tab, ‘Copy Spectrum Chart’ Button
Copies the Spectrum Chart graph to the clipboard.
4.10.3.9
‘Graph’ ribbon tab, ‘Print Spectrum Chart’ Button
Prints the Spectrum Chart.
4.10.3.10
‘Graph’ ribbon tab, ‘Export Time Series Chart’ Button
Pull down menu:
- Windows Bitmap (*.bmp)
- Compressed Bitmap (*.jpg)
- Portable Network Graphics (*.png)
- Acrobat Reader (*.pdf)
Exports the Time Series Chart to a choice of formats.
4.10.3.11
‘Graph’ ribbon tab, ‘Copy Time Series Chart’ Button
Copies the Time Series Chart graph to the clipboard.
4.10.3.12
‘Graph’ ribbon tab, ‘Print Time Series Chart’ Button
Prints the Time Series Chart.
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Appendix A: USB driver installation
As mentioned in section 1 (Installation), AvaSoft supports under the 32bit Windows Operating
Systems (XP, Vista, Windows7) two USB drivers:
- The Avantes kernel driver, which has been the standard USB driver on all 32bit O/S until
May 2011.
- The MicroSoft WinUSB driver. This driver has been the standard on Windows 64bit O/S.
Installing the WinUSB driver will be the standard on all Windows O/S, except for ancient Windows
versions that lack WinUSB driver support (like Windows 2000 and Windows98).
At PC’s where the Avantes kernel driver was installed before, a dialog is shown in which the user
can select to update to the WinUSB driver or to keep the Avantes kernel driver.
In this Appendix, some compatibility issues will be described that may occur after upgrading to
WinUSB:
1. After installing the WinUSB driver and connecting the AvaSpec-USB2 spectrometer, the
spectrometer cannot be found.
2. After installing the WinUSB driver, the spectrometers first worked fine, and the Device
Manager shows a proper installation of the WinUSB driver. However, after installing some
application software the spectrometer cannot be detected anymore. Also AvaSoft cannot
detect an AvaSpec-USB2 anymore. The Device Manager still shows a proper WinUSB driver
installation.
3. After installing the WinUSB driver, the spectrometer runs fine with AvaSoft, but not with
other application software.
A1:
Spectrometer cannot be found after update to WinUSB driver
After connecting the spectrometer to a USB port of your PC, Windows will install the device driver.
If all goes well, this will be displayed in the lower right corner of your screen with the message
‘Device driver software installed successfully’.
We have seen instances, where this message will not appear, and where it is necessary to open the
Device Manager, to let Windows find the installed driver files. To open the Device Manager, right
click ‘Computer’ in Windows Start menu, and select ‘Properties’. Then click the “Device Manager”
option.
The ‘Avantes Spectrometers’ entry will
show a yellow triangle with an
exclamation mark. Right-click the
AvaSpec-USB2 line and select the
“Update Driver Software” option, as
shown in the figure at the left. In the
next dialog, select “Search automatically
for updated driver software”. Windows
should now find the correct files and
install the driver software.
In multichannel spectrometer systems, it may be needed
to repeat this step several times (once per channel)
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A2:
Device Manager shows a proper WinUSB driver installation, but AvaSpec-USB2 cannot be
detected anymore
If the WinUSB driver has been installed properly, the Device
Manager will display the connected devices without the yellow
triangle with exclamation mark. AvaSoft can be executed and
everything runs well.
However, after installing some application software, it is possible that the spectrometer cannot be
detected anymore. AvaSoft cannot detect the AvaSpec-USB2 spectrometers either. One reason can
be that the application software uses an old as5216.dll version 1.7 or earlier, as will be described
below under A3.
The problem can also be caused by the installation program that installed the application software.
When installing AvaSoft version 7.6.0 or earlier versions, the Avantes kernel driver (AVSUSB2.sys)
will be installed, without uninstalling the WinUSB driver. The as5216.dll will try to communicate
through the most recently installed driver (avsusb2.sys), while the WinUSB driver is the one that is
active in the Device Manager. The problem can be easily solved by reinstalling the most recent
application software (AvaSoft 7.6.1 or later). In the driver selection dialog, select the
(recommended) WinUSB driver. The same situation may occur when the Avantes kernel driver is
installed by other application software (AvaSoft-Thinfilm-USB2, AvaSoft-Raman-USB2, or third party
applications).
A3:
After installing the WinUSB driver, AvaSoft 7.6.1 (or later) runs fine, but other
application software cannot detect the AvaSpec-USB2 spectrometer anymore.
Most likely, the as5216.dll version used by the other application software does not support the
WinUSB driver. The WinUSB driver is supported by the as5216.dll since version 1.8.0.0.
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Appendix B: Error Messages
AvaSoft can display error messages containing a number. The following table lists these numbers
and a description of the error:
Error code
Description
-1
Function called with invalid parameter
-2
Function called to use 16bit ADC mode, with 14bit ADC hardware
-3
Opening communication failed or time-out during communication occurred
-4
AvsHandle is unknown in the DLL
-5
Function is called while result of previous function is not received yet
-6
No answer received from device
-7
Reserved
-8
No measurement data is received at the point AVS_GetScopeData is called
-9
Allocated buffer size too small
-10
Measurement preparation failed because pixel range is invalid
-11
Measurement preparation failed because integration time is invalid for selected sensor
-12
Measurement preparation failed because of invalid combination of parameters
(e.g. integration time > 600 seconds or averages > 5000)
-13
Reserved
-14
Measurement preparation failed because no measurement buffers are available
-15
Unknown error reason received from spectrometer
-16
Error in communication occurred
-17
No more spectra available in RAM, all read or measurement not started yet
-18
DLL version information cannot be retrieved
-19
Memory allocation error in the DLL
-20
Function called before AVS_Init is called
-21
Function failed because AvaSpec is in wrong state (e.g. AVS_StartMeasurement while
measurement is pending)
-100
NrOfPixel in Device data incorrect
-101
Gain Setting Out of Range
-102
Offset Setting Out of Range
-110
Use of Saturation Detection Level 2 is not compatible with the Averaging function
-111
Use of Averaging is not compatible with the StoreToRam function
-112
Use of the Synchronize setting is not compatible with the StoreToRam function
-113
Use of Level Triggering is not compatible with the StoreToRam function
-114
Use of Saturation Detection Level 2 Parameter is not compatible with the StoreToRam
function
-115
The StoreToRam function is only supported with firmware version 0.20.0.0 or later
-116
Dynamic Dark Correction not supported
-120
Not supported by sensor type
-121
Not supported by firmware version
-122
Not supported by FPGA version
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Appendix C: Using the Ethernet spectrometer
This section describes some details to avoid common pitfalls that can occur when using the Ethernet
interface of the AS7010 spectrometer.
C1:
DHCP vs. using static IP addresses
The spectrometers are shipped with DHCP enabled. This means that they will be assigned a unique
IP address in the correct range if you connect them to a network on which a DHCP server is running.
If you connect the spectrometer to your office network for the first time, please ensure that a DHCP
server is present on that network.
The spectrometer can also be used with a static IP address configured. You can change the network
settings of the spectrometer with the IP Settings AS7010 utility that is e.g. distributed with AvaSoft
8. When using the spectrometer with a static IP address please make sure that the used IP address is
in the same range as your host PC.
When using the spectrometer within a local network (a network with only one host (PC) and one or
more Ethernet spectrometers with static IP addresses), you will have to change the IP settings of
your PC from DHCP to static as well. This is also described in the IP Settings AS7010 manual in more
detail. Of course you can also use DHCP enabled spectrometers within the local network, provided
that there is a DHCP server running on your host PC. There are several simple to use and freeware
DHCP servers for Windows, such as one available from www.dhcpserver.de.
Please consult your network administrator for the availability of any DHCP server on your network or
for using static IP addresses on the spectrometers. It is very important that the Ethernet
spectrometers are configured with the right network settings, since otherwise major network
problems can occur.
C2:
Cables
You can use standard Ethernet patch cables to connect the spectrometer to your network. If you use
a direct connection to your PC, make sure you have a GigE network connection, if you want to use a
standard Ethernet patch cable. If your PC has an older Fast Ethernet connection (100 Mbps), then
you will need a cross-connect cable.
C3:
Routers
The AvaSpec DLL uses a UDP broadcast to identify the spectrometers on the network. It is sent from
each network adapter that is found in the host PC. Most layer 3 switches and routers will not allow
this broadcast to pass, which will stop the DLL from working. If there are connection problems,
please also test a direct PC connection to make sure your router is not the cause.
C4:
Firewall
The Windows Firewall must allow both incoming and outgoing connections to the spectrometer.
If the Windows Firewall is enabled, then a dialog will appear if you first use a program that will
access the network:
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Make sure you check all three boxes and press the ‘Allow access’ button, to allow the program
access. Switching the firewall off completely will of course also work, but may not be advisable.
You may have to restart the program that uses the DLL to have things work correctly.
C5:
DLL / firmware version conflicts
With AS7010 firmware version 1.3, the discovery protocol has been changed. If your firmware is
older than version 1.3, you will not be able to use the latest versions of the AvaSpec DLL (9.2 and
later). Please contact Avantes to upgrade the spectrometer firmware to the latest version with an
update utility.
C6:
Connecting both interfaces at the same time
If you connect both the USB and Ethernet interfaces, then the USB interface will have priority. If,
however, an Ethernet connection has already been made, then plugging in a USB cable will not
break the Ethernet connection.
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