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USER'S GUIDE
Vaisala HUMICAP® Humidity and
Temperature Probe HMP155
M210912EN-C
PUBLISHED BY
Vaisala Oyj
P.O. Box 26
FI-00421 Helsinki
Finland
Phone (int.): +358 9 8949 1
Fax:
Visit our Internet pages at www.vaisala.com
.
+358 9 8949 2227
© Vaisala 2012
No part of this manual may be reproduced, published or publicly displayed in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be modified, translated, adapted, sold or disclosed to a third party without prior written permission of the copyright holder. Translated manuals and translated portions of multilingual documents are based on the original English versions. In ambiguous cases, the English versions are applicable, not the translations.
The contents of this manual are subject to change without prior notice.
This manual does not create any legally binding obligations for Vaisala towards customers or end users. All legally binding obligations and agreements are included exclusively in the applicable supply contract or the General Conditions of Sale and
General Conditions of Service of Vaisala.
________________________________________________________________________________
Table of Contents
CHAPTER 1
GENERAL INFORMATION ............................................................................ 5
About This Manual ................................................................... 5
Contents of This Manual ....................................................... 5
Version Information ............................................................... 6
Related Manuals ................................................................... 6
Documentation Conventions ................................................. 6
Safety......................................................................................... 7
Regulatory Compliances ......................................................... 7
Recycling .................................................................................. 8
Patent Notice ............................................................................ 8
Trademarks ............................................................................... 8
License Agreement .................................................................. 8
Warranty .................................................................................... 9
CHAPTER 2
PRODUCT OVERVIEW................................................................................ 11
Introduction to HMP155 ......................................................... 11
Basic Features and Options................................................ 12
Structure of the HMP155..................................................... 13
Additional Temperature Probe Option ................................ 14
Warmed Probe Option ........................................................ 15
Connection Cover Option.................................................... 15
CHAPTER 3
Installation in Radiation Shields........................................... 17
Installation in DTR13........................................................... 17
Installation in DTR503......................................................... 18
Installation in Stevenson Screen......................................... 19
8-Pin Connector...................................................................... 20
Temporary RS-485 Connection Option............................... 22
CHAPTER 4
Getting Started ....................................................................... 23
RS-485 Interface ..................................................................... 23
Serial Line Communication ................................................... 24
Installing the Driver for the USB Cable ............................... 25
Terminal Application Settings.............................................. 26
List of Serial Commands ..................................................... 28
Measurement Commands................................................... 30
R..................................................................................... 30
S ..................................................................................... 30
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SEND [ADDR] ................................................................30
SDELAY .........................................................................30
SERI [BAUD][PARITY][DATA][STOP] ...........................31
#......................................................................................31
SMODE ..........................................................................32
INTV ...............................................................................32
Formatting Commands ........................................................33
FORM .............................................................................33
UNIT [M/N] .....................................................................35
TIME ...............................................................................35
Pressure Compensation Commands ..................................36
PRES and XPRES .........................................................36
System Commands .............................................................37
FILT [0.1…1] ..................................................................37
?......................................................................................38
HELP ..............................................................................39
ERRS..............................................................................40
VERS..............................................................................40
RESET............................................................................40
Analog Output Configuration Commands ...........................41
AMODE ..........................................................................41
ASEL ..............................................................................42
ATEST ............................................................................43
AERR..............................................................................43
ADDR .............................................................................44
OPEN .............................................................................44
CLOSE ...........................................................................44
Sensor Functions ...................................................................45
Chemical Purge (Optional) ..................................................45
Automatic Chemical Purge (Interval Purge)...................46
Chemical Purge in Power Up .........................................46
Manual Chemical Purge .................................................46
Starting and Configuring Chemical Purge ...........................47
PUR ................................................................................47
Sensor Heating....................................................................48
Setting Humidity Sensor Heating ...................................48
XHEAT............................................................................49
CHAPTER 5
Periodic Maintenance.............................................................51
Cleaning ..............................................................................51
Changing the Probe Filter ...................................................51
Changing the Sensor...........................................................52
Error States .............................................................................54
Technical Support ..................................................................55
Product Returns......................................................................55
CHAPTER 6
CALIBRATION AND ADJUSTMENT...........................................................57
Push-Button Calibration ........................................................59
Two-Point Humidity and Temperature Adjustment .............59
One-Point Humidity and Temperature Adjustment .............61
Passive Output Version Push-Button Calibration................62
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Serial Line Calibration ........................................................... 63
Two-Point Humidity Adjustment .......................................... 63
Two-Point Temperature Adjustment ................................... 64
Relative Humidity Adjustment after Sensor Change........... 65
FCRH ............................................................................. 65
One-Point Humidity and Temperature Adjustment ............. 65
User Adjustment Commands ................................................ 66
L .......................................................................................... 66
LI ......................................................................................... 66
Feeding Adjustment Information.......................................... 66
CTEXT................................................................................. 67
CDATE ................................................................................ 67
Analog Output Adjustment.................................................... 67
ACAL [0/1] ........................................................................... 68
MI70 Check and Adjustment ................................................. 68
CHAPTER 7
Performance ........................................................................... 71
Relative Humidity ................................................................ 71
Temperature........................................................................ 72
Operating Environment ......................................................... 73
Calculated Variables .............................................................. 74
Accuracies of Calculated Variables ..................................... 74
Accuracy of Dew point Temperature °C.............................. 74
Accuracy of Mixing Ratio g/kg (Ambient Pressure 1013
mbar) ................................................................................... 74
Accuracy of Wet Bulb Temperature °C ............................... 75
Accuracy of Dew point Measurement ................................. 75
Inputs and Outputs ................................................................ 75
Mechanics ............................................................................... 76
Options and Accessories ...................................................... 77
Dimensions in mm (inches) .................................................. 78
HMP155 Probe.................................................................... 78
Additional Temperature Probe ............................................ 78
APPENDIX A
CALCULATION FORMULAS ...................................................................... 79
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List of Figures
Figure 1
HMP155 Probe .........................................................................13
Figure 2
HMP155 with Additional T-probe..............................................14
Figure 3
HMP155 with Optional Connection Cover................................15
Figure 4
HMP155 with T-probe Installed in DTR13................................17
Figure 5
HMP155 Installed in DTR503 ...................................................18
Figure 6
HMP155 with T-Probe Installed in Stevenson Screen .............19
Figure 7
Wiring of HMP155 8-Pin Connector .........................................20
Figure 8
HMP155D Block Diagram and Wiring ......................................21
Figure 9
HMP155A/E Block Diagram and Wiring ...................................21
Figure 10
PuTTY Terminal Application.....................................................27
Figure 11
Decrease of Sensor Gain .........................................................46
Figure 12 Changing the HUMICAP
®
180/180R Sensors ...........................53
Figure 13
HMP155 Adjustment Buttons ...................................................58
Figure 14
Accuracy over Temperature Range: Voltage and RS-485.......72
Figure 15
Accuracy of Dew point Measurement.......................................75
Figure 16
Probe Dimensions ....................................................................78
Figure 17
Additional Temperature Probe Dimensions..............................78
List of Tables
Table 1
Manual Revisions .......................................................................6
Table 2
Related Manuals.........................................................................6
Table 3
Quantities Measured by HMP155.............................................11
Table 4
Quantities Calculated by HMP155............................................12
Table 5
Default Serial Communication Settings ....................................24
Table 6
Measurement Commands ........................................................28
Table 7
Formatting Commands .............................................................28
Table 8
Chemical Purge Commands (Optional)....................................28
Table 9
Calibration and Adjustment Commands...................................29
Table 10
Setting and Testing the Analog Outputs...................................29
Table 11
Other Commands .....................................................................29
Table 12
Selection of Output Modes .......................................................32
Table 13
FORM Command Modifiers......................................................33
Table 14
Symbols Used in FORM Checksum Equations........................34
Table 15
Error Messages ........................................................................54
Table 16
Relative Humidity Performance ................................................71
Table 17
Temperature Performance .......................................................72
Table 18
Operating Environment.............................................................73
Table 19
Calculated Variables.................................................................74
Table 20
Outputs .....................................................................................75
Table 21
Average current consumption (+15 VDC, load 100 kOhm).....76
Table 22
Operating Voltage and Settling Time .......................................76
Table 23
Mechanical Specifications ........................................................76
Table 24
Options and Accessories..........................................................77
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Chapter 1 ________________________________________________________ General Information
CHAPTER 1
GENERAL INFORMATION
This chapter provides general notes for the manual and the product.
About This Manual
This manual provides information for installing, operating, and maintaining Vaisala HUMICAP
®
Humidity and Temperature Probe
HMP155.
Contents of This Manual
This manual consists of the following chapters:
- Chapter 1, General Information, provides general notes for the manual
and the Humidity and Temperature Probe HMP155.
- Chapter 2, Product Overview, introduces the features, advantages, and
the product nomenclature of the Humidity and Temperature Probe
HMP155.
- Chapter 3, Installation, provides you with information that is intended
to help you install the Humidity and Temperature Probe HMP155.
- Chapter 4, Operation, contains information that is needed to operate
the Humidity and Temperature Probe HMP155.
- Chapter 5, Maintenance, contains information that is needed in basic
maintenance of the Humidity and Temperature Probe HMP155.
- Chapter 6, Calibration and Adjustment, provides information and
instructions concerning calibration and adjustment of the Humidity and Temperature Probe HMP155.
- Chapter 7, Technical Data, provides the technical data of the Humidity
and Temperature Probe HMP155.
- Appendix A, Calculation Formulas, presents the equations used in the
Humidity and Temperature Probe HMP155 to calculate values of dew point, mixing ratio, absolute humidity and enthalpy in normal pressure.
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Version Information
Table 1
Manual Code
M210912EN-C
M210912EN-B
Manual Revisions
Description
November 2012. This manual. Added the membrane filter option. Added information about the cable cover.
Previous version. March 2009. Removed the description for the OVERICE command, updated the description of the ASEL command.
Related Manuals
Table 2
Manual Code
M210913EN
Related Manuals
Manual Name
Vaisala HUMICAP® Humidity and Temperature Probe
HMP155 Quick Reference Guide
Documentation Conventions
Throughout the manual, important safety considerations are highlighted as follows:
WARNING Warning alerts you to a serious hazard. If you do not read and follow instructions very carefully at this point, there is a risk of injury or even death.
CAUTION Caution warns you of a potential hazard. If you do not read and follow instructions carefully at this point, the product could be damaged or important data could be lost.
NOTE Note highlights important information on using the product.
6 ________________________________________________________________ M210912EN-C
Chapter 1 ________________________________________________________ General Information
Safety
Vaisala HUMICAP
®
Humidity and Temperature Probe HMP155 delivered to you has been tested for safety and approved as shipped from the factory. Note the following precautions:
WARNING Ground the product, and verify outdoor installation grounding periodically to minimize shock hazard.
CAUTION Do not modify the unit. Improper modification can damage the product or lead to malfunction.
Regulatory Compliances
Vaisala HUMICAP
®
Humidity and Temperature Probe HMP155 is in conformity with the provisions of the following EU directives:
- EMC-Directive
Conformity is shown by compliance with the following standards:
- EN 61326-1: Electrical equipment for measurement, control, and laboratory use – EMC requirements – for use in industrial locations.
- EN 550022: Information technology equipment – Radio disturbance characteristics – Limits and methods of measurement.
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Recycling
Recycle all applicable material.
Dispose of batteries and the unit according to statutory regulations. Do not dispose of with regular household refuse.
Patent Notice
Vaisala HUMICAP
®
Humidity and Temperature Probe HMP155 is protected by the following patents and patent applications and their corresponding national rights:
Finnish patent 98861, French patent 6650303, German patent 69418174,
Japanese patent 3585973, UK patent 0665303, U.S. patent 5607564.
Trademarks
HUMICAP
®
is a registered trademark of Vaisala.
Windows® is a registered trademark of Microsoft Corporation in the
United States and/or other countries.
License Agreement
All rights to any software are held by Vaisala or third parties. The customer is allowed to use the software only to the extent that is provided by the applicable supply contract or Software License Agreement.
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Chapter 1 ________________________________________________________ General Information
Warranty
Visit our Internet pages for standard warranty terms and conditions: www.vaisala.com/warranty .
Please observe that any such warranty may not be valid in case of damage due to normal wear and tear, exceptional operating conditions, negligent handling or installation, or unauthorized modifications. Please see the applicable supply contract or Conditions of Sale for details of the warranty for each product.
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Chapter 2 __________________________________________________________ Product Overview
CHAPTER 2
PRODUCT OVERVIEW
This chapter introduces the features, advantages, and the product nomenclature of the Vaisala HUMICAP
®
Humidity and Temperature
Probe HMP155.
Introduction to HMP155
The HMP155 probe provides reliable humidity and temperature measurement in a wide range of applications. Humidity measurement is based on the capacitive thin film HUMICAP
® polymer sensor.
Temperature measurement is based on resistive platinum sensors (Pt100).
Both the humidity and temperature sensors are located at the tip of the probe, protected by a removable filter.
The HMP155 comes in active and passive output models where the relative humidity voltage output is similar, but the temperature output is either active or passive (resistive). Active output version has either two analog outputs or an RS-485 digital output. Passive output version has 4wire temperature measurement and an analog voltage output for relative humidity measurement.
The quantities measured by HMP155 are presented in Table 3 below.
The quantities calculated from the measured quantities are presented in
NOTE Calculated quantities are not available with the passive output version.
Table 3 Quantities Measured by HMP155
Relative humidity (RH)
Temperature (T)
Additional T-probe temperature
(T a
)
RH
T
T a
Unit
%RH
ºC
Unit
%RH
ºF
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Table 4 Quantities Calculated by HMP155
Unit Unit
Dew point / Frost point
Temperature (T d/f
)
Dew point Temperature (T d
) TD
Mixing ratio (x) X
ºC g/kg
ºF gr/lb.
Wetbulb temperature (T w
) TW ºC ºF
Basic Features and Options
- Can be used to replace HMP45A/D, also in radiation shields
- Improved performance with the HUMICAP
®
180R sensor and alternatively the HUMICAP
®
180RC sensor. Also available with the
HUMICAP
®
180 sensor.
- Warmed humidity probe for improved performance in constant high humidity (active output version).
- Different voltage ranges possible: 0...1 V, 0…5 V, 0…10 V (active and passive output versions).
- Different T-output scales possible: -40…+60°C, -20…+40°C,
-80…+60°C (active output version)
- Chemical purge option for applications where interfering chemicals in the measuring environment pose a risk (active output version).
- Additional temperature probe (T-probe) with fast response (active output version).
- USB connectivity for service connections via the optional USB-M12 cable. radiation shields.
- Installation kit for Stevenson screen (active and passive output version, both with and without additional T-probe).
- MI70 connectivity for field checking and calibration.
- Optional connection cover for additional protection in wet environments.
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Chapter 2 __________________________________________________________ Product Overview
Structure of the HMP155
0801-070
HMP155 Probe Figure 1
The numbers refer to Figure 1 above.
1 = Filter
3 = 8-Pin male connector (M12)
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Additional Temperature Probe Option
Figure 2
1206-038
HMP155 with Additional T-probe
The active output version of HMP155 can be ordered with an additional
temperature probe option, see Figure 2 above. When the additional T-
probe is in use, the relative humidity value is calculated based on the T d
(dew point) value obtained from the humidity probe and the T a
value obtained from the T-probe.
When installing HMP155 with T-probe, it is important to make sure that the humidity probe and the T-probe are installed in the same conditions in order to get accurate readings. Even a slight difference in temperature conditions between the T-probe and the humidity probe will result in false RH readings. The two probes need to be installed so that the humidity probe does not heat the T-probe, but is close enough for the probes to share the same environment conditions. When the RH reading is required, always install the T-probe in the place where you need the reading from.
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Chapter 2 __________________________________________________________ Product Overview
Warmed Probe Option
In changing temperature conditions with high humidity, the probe temperature can lag behind the temperature of the surrounding air and this can cause a risk of condensation on the sensor. A wet probe cannot observe the actual humidity in the ambient air. If the condensed water is contaminated, the life span of the probe may shorten and the calibration may change.
The HMP155 warmed probe is heated continuously so that its temperature is always higher than that of the environment. This prevents condensation on the probe. With the additional temperature probe it is possible to calculate the true RH based on the non-heated (ambient) temperature information. If the warming is selected but the additional temperature probe is not present, HMP155 only produces dew point and mixing ratio output.
Connection Cover Option
Figure 3 HMP155 with Optional Connection Cover
1206-039
An optional connection cover is available for enhanced protection in wet environments such as coasts or rainforests.
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Chapter 3 _______________________________________________________________ Installation
CHAPTER 3
INSTALLATION
This chapter provides you with information on how to install HMP155 in different situations.
Installation in Radiation Shields
In order to reach the maximum performance level of the HMP155 probe,
Vaisala recommends installing the HMP155 in a radiation shield, for
example in DTR503, in DTR13 or in a Stevenson screen. See Figure 4
below, Figure 5 on page 18 and Figure 6 on page 19.
Installation in DTR13
0801-071
Figure 4 HMP155 with T-probe Installed in DTR13
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Installation in DTR503
Figure 5
0801-072
HMP155 Installed in DTR503
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Chapter 3 _______________________________________________________________ Installation
Installation in Stevenson Screen
Figure 6
0805-008
HMP155 with T-Probe Installed in Stevenson Screen
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8-Pin Connector
Both the passive and active versions of HMP155 come with an 8-pin
M12 male connector on the bottom of the probe.
Figure 7
0507-044
Wiring of HMP155 8-Pin Connector
The pins of the connector for HMP155 passive output version in Figure 7
are (open end wire colors in brackets):
2 = RH
OUT
0…1 V (brown)/RS-485-B
6 = A
GND
(pink)/RS-485-A
7 = V
CC
(blue)
The pins of the connector for HMP155 active output version in Figure 7
are (open end wire colors in brackets):
1 = V
OUT
1 (white)
3 = A
GND
(green)
4 = V
OUT
2 (yellow)
5 = -
7 = V
CC
(blue)
The last entry in the list of pins, SHIELD, is not a pin but one of the conductors in the connection cable. The SHIELD wire color is black.
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Chapter 3 _______________________________________________________________ Installation
The left side of Figure 8 below shows the HMP155D block diagram. The
right side shows an example of connections. For the pin layout see
Figure 8 HMP155D Block Diagram and Wiring
1205-105
The left side of Figure 9 below shows the HMP155A/E block diagram.
The right side shows an example of connections. For the pin layout see
Figure 9 HMP155A/E Block Diagram and Wiring
1205-106
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Temporary RS-485 Connection Option
It is possible to have a temporary RS-485 connection also in the passive output version by powering up the probe, while simultaneously holding
down the ADJ button, see Figure 13 on page 58. After the probe has
restarted, pins 2 and 6 then have the RS-485 signal. For the order of the
pins, see Figure 7 on page 20. The default signals are returned to the pins
after the next power-up.
The active output version with two voltage channels includes also a solid
RS-485 connection with dedicated signal pins that can be used as a temporary digital service port. However, Vaisala does not recommend the continuous, parallel use of both digital and analog outputs, because this may affect the temperature measurement accuracy due to increased power consumption and probe self-heating.
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Chapter 4 ________________________________________________________________ Operation
CHAPTER 4
OPERATION
This chapter contains information that is needed to operate this product.
Getting Started
After the Vaisala HUMICAP
®
Humidity and Temperature Probe
HMP155 has been connected to a power supply, the serial line and the analog outputs are operational depending on product model.
RS-485 Interface
HMP155 supports a two-wire RS-485 communication. The RS-485 interface is non-isolated and offers a maximum communications rate of
19200 bits/s. There is no internal termination for the RS-485 on the
HMP155. If any termination is needed, the bus should be terminated at both ends. The recommended termination is R termination with 120 Ohm resistors.
Typically the termination resistors are only needed when the fastest communications rate (19200 bit/s) is used for longer distances. If the resistors are used, the possible increase in current consumption should be taken into account.
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Serial Line Communication
Connect the probe to a PC, for example, by using a USB cable (optional accessory item: 221040). Connect the USB cable to the 8-pin connector on the bottom of the probe. Before you can use the USB cable, you must
install the provided USB driver on your PC, see Installing the Driver for the USB Cable on page 25.
NOTE
NOTE
When using the USB-cable, no separate power unit is needed. The probe is powered through the USB port.
Heating and Purge functions may not work properly with the USB cable due to limited USB powering capability. This depends on the computer used and environmental conditions.
HMP155 does not echo typed characters back to the terminal screen. To see the commands you type, you need to enable the "local echo" -setting in your terminal program.
A new command cannot be received while the instrument is sending data out. Wait until the instrument has completed its response before entering the next command.
NOTE In the RUN mode, the instrument may send the measurement data message while you are typing the S command to stop the sending.
Therefore, you may need to repeat the S command. This must be noted especially when designing computer programs to access the HMP155.
You can also use the Esc key on your keyboard to stop the sending.
Table 5 Default Serial Communication Settings
Parameter Value
Bauds 4800
Parity Even
Data bits 7
Stop bits
Flow control
1
None
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Chapter 4 ________________________________________________________________ Operation
After power-up the probe (in STOP-mode) outputs the software version and the command prompt.
HMP155 1.00
>
In RUN mode a measurement output starts immediately after power-up.
In POLL mode, the probe does not output anything after power-up, see
Installing the Driver for the USB Cable
Before taking the USB cable into use, you must install the provided USB driver on your PC. The driver is compatible with Windows 2000,
Windows XP, and Windows Vista.
1. Check that the USB cable is not connected. Disconnect the cable if you have already connected it.
2. Insert the media that came with the cable, or download the driver from www.vaisala.com.
3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes.
4. After the driver has been installed, connect the USB cable to a USB port on your PC. Windows will detect the new device, and use the driver automatically.
5. The installation has reserved a COM port for the cable. Verify the port number, and the status of the cable, using the Vaisala USB
Instrument Finder program that has been installed in the
Windows Start menu. The reserved ports are also visible in the
Ports section of the Windows Device Manager.
Remember to use the correct port in the settings of your terminal program. Windows will recognize each individual cable as a different device, and reserve a new COM port.
There is no reason to uninstall the driver for normal use. However, if you wish to remove the driver files and all Vaisala USB cable devices, you can do so by uninstalling the entry for Vaisala USB Instrument Driver from the Add or Remove Programs (Programs and Features in
Windows Vista) in the Windows Control Panel.
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Terminal Application Settings
The steps below describe how to connect to the HMP155 using the
PuTTY terminal application for Windows (available for download at www.vaisala.com
) and the USB serial interface:
1. Connect the USB serial interface cable between your PC and the
RS-485 port of the HMP155.
2. Start the PuTTY application. port is selected in the Serial line to connect to field.
You can check which port the USB cable is using with the Vaisala
USB Instrument Finder program that has been installed in the
Windows Start menu.
4. Check that the other serial settings are correct for your connection,
and change if necessary. Refer to Table 5 on page 24 for the default
serial line settings of the HMP155. using the serial line.
If PuTTY is unable to open the serial port you selected, it will show you an error message instead. If this happens, restart PuTTY and check the settings.
6. You may need to adjust the Local echo setting in the Terminal category to see what you are typing on the serial line. To access the configuration screen while a session is running, click the right mouse button over the session window, and select Change
Settings... from the pop-up menu.
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Chapter 4 ________________________________________________________________ Operation
Figure 10 PuTTY Terminal Application
0903-025
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List of Serial Commands
Most of the commands listed below are relevant only in the digital output version of HMP155. These commands are marked with an * in the description column to make them easier to tell apart. The bold text in the brackets is the default setting. To issue a command, type it on your computer and press the Enter key.
Table 6 Measurement Commands
Command Description
R Start the continuous outputting
S
INTV [0 ... 255 S/MIN/H]
Stop the continuous outputting
Set the continuous output interval (for RUN mode)
SEND [0 ... 99]
SMODE
[STOP/RUN/POLL/SEND]
SDELAY[0 … 255]
Output the reading once *
Set the serial interface mode *
SERI [baud p d s]
View or set user port (RS-485) answer minimum delay *
User Port settings (Default: 4800 E 7 1) baud:
300 ... 115200 *
ADDR [0 ... 99]
OPEN [0 ... 99]
CLOSE
Set the probe address (for POLL mode) *
Open a temporary connection to a POLL mode device *
Close the temporary connection (Back to POLL mode) *
Table 7 Formatting Commands
Command Description
FORM Set the output format of SEND and R commands *
TIME [HH MM SS]
UNIT
Set or display the time *
Select the metric or non-metric output units *
Table 8 Chemical Purge Commands (Optional)
Command Description
PUR Set the automatic chemical purge *
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Chapter 4 ________________________________________________________________ Operation
Table 9 Calibration and Adjustment Commands
Command Description
# Force connection settings 19200 baud, N, 8, 1
ACAL [0/1]
CDATE
CRH
Analog output calibration
Set the calibration date
Relative humidity calibration
CTA
FCRH
CTEXT
L
LI
Additional temperature probe calibration *
Relative humidity calibration after sensor change
Give the text to calibration information field
Displays user adjustment parameters
Displays new values for the user adjustment parameters
Table 10 Setting and Testing the Analog Outputs
Command Description
AMODE View the analog output modes
ASEL Set or view analog output quantities and scaling
AERR
ATEST
Change the analog error output values
Force the analog outputs to entered values
Table 11 Other Commands
Command Description
? Output information about the device
?? Output information about the device in POLL mode *
ERRS
FILT [0.1…1]
HELP
PRES [hPa]
List present probe errors
Set the result filtering
Lists the available commands
Set the value for pressure compensations
RESET
VERS
XHEAT
XPRES [bar]
Resets the probe.
Display the software version information
Sensor heating *
Set the value for pressure compensations, temporarily
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Measurement Commands
R
Enter the R command to start the continuous output of measurements.
This command starts a temporary RUN mode. To change to permanent
RUN mode, use the SMODE command.
Example:
>r
RH= 33.0 %RH T= 22.1 'C
>
If a value is too long to fit to the allocated space in the output, or if there is an error in outputting the quantity, the value is displayed with stars ‘*’.
The output format can be adjusted with the FORM command and the output interval can be changed with the INTV command.
S
Use the S command to end the RUN mode. After this command all other commands can be used. You can also press the Esc key on your keyboard or reset the probe to stop the outputting.
See SMODE command on page 31 to change the default (power up)
operation mode.
SEND [ADDR]
Use the SEND command, where ADDR is the address of the probe, to output the reading once in STOP mode. In STOP mode, the SEND command can also be used without the address. The output format depends on which parameters the probe can output.
Example without parameter:
>send
RH= 24.9 %RH T= 22.1 'C
>
SDELAY
To view or set the minimum answer delay for the user port (RS-485), use the SDELAY command. You can set the SDELAY value between
0 ... 255. By default the value is set to 10.
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Where
0 = No extra delay added
1 = 4-8 ms extra delay
255 = 1024 ms extra delay
Example:
>sdelay 15
Serial delay : 15
>
SERI [BAUD][PARITY][DATA][STOP]
To set the communication settings, use the SERI serial line command.
SERI [BAUD][PARITY][DATA][STOP] where baud = Bit rate (300, 600, 1200, 2400, 4800, 9600,19200) parity = Parity (n = none, e = even, o = odd) data = Data bits (7 or 8) stop = Stop bits (1 or 2)
You need to reset the probe to activate the new communication settings set with SERI command.
The settings can be changed one parameter at a time or all parameters at once.
Examples:
Changing all parameters
>seri 9600 e 7 1
Baud P D S : 9600 E 7 1
>
Changing baud only
>seri 4800
Baud P D S : 4800 E 7 1
>
#
To force the settings 19200 baud, no parity, 8 data bits, 1 stop bit, enter the # command on the first three seconds after power-up.
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The settings are temporary, and last only for a single session at a time.
On the next connection HMP155 reverts to the settings last set with the
SERI command.
SMODE
Use the SMODE command to set the user port to permanent STOP,
RUN, POLL or SEND mode.
SMODE [xxxx] where xxxx= STOP, RUN, POLL or SEND
Example:
>smode
Serial mode : STOP ? POLL
>
Table 12 Selection of Output Modes
Mode Output
STOP Only with the SEND command
RUN Automatic output
All (default mode)
Only command S
POLL Only with the SEND [addr] command ??, SEND [addr], OPEN [addr]
Selected output mode will be activated after power outages.
INTV
Use the INTV command to set the outputting interval for the RUN mode.
The default value for this command is 2 seconds.
INTV [xxx yyy] where xxx = Output interval (0...255) where 0 produces an output whenever a new measurement is made. Interval 1 s produces repeats of the previous measurement if no newer measurement is available. yyy = Unit (s, min or h)
Example:
>intv 1 min
Interval : 1 min
>
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Chapter 4 ________________________________________________________________ Operation
Formatting Commands
FORM
Use the serial line command FORM to change the format or select certain quantities for the output commands SEND and R.
FORM [x] where
Formatter string consists of quantities and modifiers. You can only give a maximum of 73 characters after the command on the command line.
When entering the command, use the abbreviations of the quantities. For
more information on quantities, see Table 3 and Table 4 on page 11.
The modifiers are presented in Table 13 below.
Table 13 FORM Command Modifiers
Modifier Description quantity Quantity name (for example RH, T or TDF) x.y Length modifier (number of digits and decimal places)
#t Tabulator
#r Carriage-return
#xxx
U5
ADDR
CS2
CS4
ERR
STAT h
H
S
X
Special character with decimal code "xxx"
Unit field and length
Probe address with two characters [00...99]
Modulus-256 checksum of message sent so far, hexadecimal format.
Modulus-65536 checksum of message sent so far, hexadecimal format.
Error flags for P, T, Ta, RH [0000 ... 1111], 0 = no error
Probe status in 7 character field, for example: probe heating active, power purge heating active, temperature purge cooling active, temperature sensor heating active, temperature
Example:
>form "Temperature=" 5.2 t #r#n
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OK
>send
Temperature= 24.23
>
>form "Twet=" 6.3 tw U3 #t "T=" t U3 #r#n
OK
>send
Twet= 11.290'C T= 24.231'C
>
>form 5.1 rh #t t #t tdf #r#n
OK
>send
15.6 24.2 -3.1
>
FORM / command returns the default output format. The default output format depends on the device configuration. FORM command without formatter string returns the current output format of the probe.
>form /
OK
>send
RH= 23.8 %RH T= 19.4 'C
>
Checksums are calculated as described in the equations below. cs
2
i n
1 b i mod 256 cs
4 b i
'
cs x b i
'
b i
0 i n
1 b '
1 b i mod
b '
2
65536
b ' n if if b i b i
3 6
3 6 and or b i b i
4 2
4 2
Table 14 Symbols Used in FORM Checksum Equations
Symbol Description cs
2 cs
4 cs x b i n
36
42
Value of CS2 checksum in the output message.
Value of CS4 checksum in the output message.
Value of CSX checksum in the output message.
Value of the byte at position i (1-based) in the output message.
Number of bytes in the output message before the CS2, CS4, or
CSX field (including earlier checksum fields, if any).
Bit-wise exclusive-or operator.
Byte value of ASCII $ character.
Byte value of ASCII * character.
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Chapter 4 ________________________________________________________________ Operation
UNIT [M/N]
Use the UNIT command to select metric or non-metric output units.
UNIT [M/N] where
Example:
>unit n
Units : non metric
>
TIME
To set or display the current time, use the TIME serial line command.
TIME [HH MM SS]
Example:
> time 12 00 00
Time : 12:00:00
>
When you set the current time for the probe with the TIME command, the time will be displayed as long as the probe is turned on. The time setting will not be stored in any memory. At reset or when the probe is turned off, the time will go back to 00:00:00.
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NOTE
Pressure Compensation Commands
PRES and XPRES
Use the PRES serial line command to set ambient pressure value for fixed pressure compensation. If the value is changed frequently, use the
XPRES serial line command. Its value is cleared to 0.0 at reset; if it is set to other than 0, it overrides the setting given with the PRES command.
In normal pressure conditions, PRES command is not needed. But if mixing ratio is used in high altitudes, the pressure changes will increase the mixing ratio.
Use the serial line and do the following:
PRES [a.aaaa] where a.aaaa = Ambient pressure value (bar)
Example:
>pres
Pressure : 1.013 bar ?
>
XPRES [a.aaaa] where a.aaaa = Ambient pressure value (bar)
Example:
>xpres
Pressure: 0.000 bar ?
>
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Chapter 4 ________________________________________________________________ Operation
System Commands
The commands introduced in this section are used for setting the filtering level, checking the probe configuration, listing available commands and possible error messages, and displaying the software information of the probe.
FILT [0.1…1]
Use the FILT [xxx] serial line command to set the filtering level. The default setting is 1. The output is calculated based on the following formula: [( new result * filt) + ( old result * (1.0 - filt))]. This means that with FILT value 1 the probe will take only the latest measurement into account, but with FILT value 0.1 a new output is a combination of the previous output (90%) and the latest measurement (10%).
FILT [xxx] where xxx = 0.1…1 where 1.0 = no filter and 0.1 = about 16 moving average
Example:
>filt
Filter : 0.800 ?
>
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?
Use the ? serial line command to check the current probe configuration.
?? command is similar but can also be used if the probe is in POLL mode.
Example:
>?
HMP155 1.00
Serial number : C1230001
Batch number : B2350090
Module number : C4840248
Sensor number : B4250001
Sensor model : Humicap 180
Cal. date : YYYYMMDD
Cal. info : NONE
Time : 00:01:06
Serial mode : STOP
Baud P D S : 4800 E 7 1
Output interval: 2 S
Serial delay : 0
Address : 0
Pressure : 1.013 bar
Filter : 0.800
Ch0 output : 0 ... 1 V
Ch1 output : 0 ... 1 V
Ch0 error out : 0.00 V
Ch1 error out : 0.00 V
Ch0 RH lo : 0.00 %RH
Ch0 RH hi : 100.00 %RH
Ch1 T lo : -40.00 'C
Ch1 T hi : 60.00 'C
>
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HELP
Use the HELP command to list the available commands.
Example:
>help
?
ACAL ch0/ch1
ADDR 0...99
AERR err1 err2
AMODE ch1 ch2
ASEL quantity1 quantity2 low1 high1 low2 high2
ATEST value1 value2
CDATE 'cal.date'
CLOSE
CRH
CT
CTA
CTEXT 'cal.info'
ERRS
FCRH
FILT value
FORM 'format string'
HELP
INTV 0...255 s/min/h
L
LI
OPEN addr
PRES bar
PUR on/off
R
RESET
S
SDELAY 0...255
SEND addr
SERI baud p d s
SMODE stop/run/poll
TIME hh:mm:ss
UNIT m/n
VERS
XHEAT on/off
XPRES bar
>
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ERRS
Use the ERRS command to display probe error messages, see Table 15 on page 54.
Example:
>errs
No errors
>
VERS
Use the VERS command to display software version information.
Example:
>vers
HMP155 1.01
>
NOTE
RESET
Use the RESET command to reset the device. The user port switches to start-up output mode selected with SMODE command.
The RESET command returns the passive output version back to analog output mode.
Example:
>reset
HMP155 1.00
>
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Chapter 4 ________________________________________________________________ Operation
Analog Output Configuration Commands
The analog output(s) are set in the factory according to the order form. In case you want to change the settings, follow these instructions.
NOTE The serial line commands AMODE, ASEL and ATEST cannot be used with the passive output version of HMP155.
AMODE
Use the serial line to select and scale the analog output quantities.
Connect the probe to the PC and then open the terminal connection between your PC and the probe.
The probe needs to be in ADJUST mode for the AMODE command to work. To put the probe in ADJUST mode, hold down the ADJ button until a green LED lights up.
Check the analog output modes with the AMODE command.
Analog output modes are:
NOTE
Example:
>amode 3 3
Ch0 : 0 ... 1V
Ch1 : 0 ... 1V
>
Analog output calibration is valid only for the factory settings. If you change the analog output mode with AMODE command, you must
continue by entering the ACAL command, see ACAL on page 68.
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ASEL
Use the ASEL command to select the quantities and scaling for analog outputs of the HMP155. Note that the optional quantities can be selected only if they have been selected when ordering the device. Quantities and
their abbreviations are listed in Table 3 on page 11 and Table 4 on page
ASEL [CH1 CH2] [low1 high1 low2 high2]
Where
CH1 = Quantity of channel 1
CH2 = Quantity of channel 2 low1 = Low limit of channel 1 high1 = High limit of channel 1 low2 = Low limit of channel 2 high2 = High limit of channel 2
Example 1 : To set the scaling of the outputs without changing the quantities, enter the command without parameters. The probe will ask for the limits. Note that ch0 is channel 1 and ch1 is channel 2.
>asel
Ch0 T lo : -40.00 'C ?
Ch0 T hi : 60.00 'C ?
Ch1 RH lo : 0.00 %RH ?
Ch1 RH hi : 100.00 %RH ?
Example 2 : To set the output quantities of the channels, enter the quantities as parameters. The probe will ask for the limits. Always specify the quantities for both channels.
>asel t td
Ch0 T lo : -40.00 'C ?
Ch0 T hi : 60.00 'C ?
Ch1 Td lo : -60.00 'C ?
Ch1 Td hi : 40.00 'C ?
Example 3 : To set the quantities and scaling with a single command, enter the quantities and limits as parameters according to the command syntax.
>asel rh td 0 100 -60 60
Ch0 RH lo : 0.00 %RH
Ch0 RH hi : 100.00 %RH
Ch1 Td lo : -60.00 'C
Ch1 Td hi : 60.00 'C
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Chapter 4 ________________________________________________________________ Operation
ATEST
Use the serial line to test the operation of all the analog outputs. Use the
ATEST command to force the analog outputs to entered values. The set values remain valid until you enter the ATEST command without parameters or reset the probe. Entering the ATEST command without parameters outputs the current output value.
ATEST [V] [V] where
V
V
= Output value for channel 1 (V)
= Output value for channel 2 (V)
Example 1:
> atest
2.412 6301
1.943 5090
>
Example 2:
> atest 1.5 1.5
1.500 3948
1.500 3948
>
NOTE
AERR
Use the AERR serial line command to set or view the error output from analog outputs.
AERR [CH0ERR/CH1ERR] where
CH0ERR output
Example:
>aerr
Ch0 error out : 10.000V ? 0
Ch1 error out : 1.000V ? 0
>
The error output value must be within the valid range of the output mode.
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NOTE The error output value is outputted only when there are minor electrical faults such as humidity sensor damage. When there is a severe device malfunction, the error output value is not necessarily shown.
ADDR
Addresses are required only for POLL mode (see serial line command
SMODE on page 31) and intended for multi-purpose RS485 buses. Use
the ADDR command to input the RS-485 probe address. Without parameters, ADDR command displays current probe address. When a parameter is specified , it sets the probe address to the given value.
ADDR [0…99] where
0…99 = address (default = 0)
Example: the probe is configured to address 2.
>addr
Address : 0 ? 2
>
OPEN
When all probes on the RS-485 bus are in POLL mode, the OPEN command sets one probe temporarily to STOP mode so that other commands can be entered.
OPEN [ADDR] where
ADDR =address of the probe (0 ... 99)
CLOSE
The CLOSE command places the probe in temporary POLL mode. After this you can only use the commands OPEN, SEND, and ??.
Example:
>close line closed
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Chapter 4 ________________________________________________________________ Operation
Sensor Functions
The active output version of HMP155 includes optional functions such as chemical purge and sensor heating. These functions are described in more detail in this section.
NOTE
NOTE
Chemical Purge (Optional)
In some specific applications the sensor gain may decrease gradually due to an interference caused by a particular chemical present in the measured gas, for example. The decrease of sensor gain due to an interfering chemical and the effect of the chemical purge process are
illustrated below, see Figure 11 below. The sensor polymer absorbs the
interfering chemical; and this reduces the ability of the polymer to absorb water molecules and consequently the sensor gain decreases. In chemical purge, heating the humidity sensor to a temperature level of approximately +180 °C for several minutes evaporates the interfering chemical.
The purge function starts with heating stage, continues with settling and when the temperature of the sensor is decreased, the probe returns to normal mode. The whole cycle takes about 6 minutes.
Chemical purge function locks the output values for about 6 minutes.
Avoid using the purge function in low (below freezing) temperatures.
Low temperatures decrease the effectivity of purge. Also, the lower the temperature, the longer it takes for the sensor to return to normal functionality.
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0508-035
Figure 11 Decrease of Sensor Gain
Automatic Chemical Purge (Interval Purge)
When HMP155 leaves the factory the automatic chemical purge takes place repeatedly with the time intervals set in the factory, if this option is chosen. You can change the interval in which the purge takes place by using serial commands. This can be necessary if the measuring environment contains high concentrations of interfering chemicals. The automatic chemical purge can also be turned off if necessary.
Chemical Purge in Power Up
Chemical purge (start-up purge) can be set to start within 10 seconds from the power-up of the device.
Manual Chemical Purge
The chemical purge must be performed always before RH calibration
(see section Calibration and Adjustment on page 57) or when there is a
reason to believe that a sensor has become exposed to an interfering chemical. Manual chemical purge can be activated by turning the power up purge on temporarily and resetting the probe. After the operation, the
power up purge can be turned off, see PUR command on page 47. Make
sure that the temperature of the sensor has come down to normal temperature before starting a calibration.
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Chapter 4 ________________________________________________________________ Operation
Starting and Configuring Chemical Purge
In this section, the function and use of the chemical purge option is explained.
PUR
With PUR command, you can enable or disable automatic and power-up chemical purge and set the interval for automatic purge. If the sensor is exposed to chemicals it is recommended to have the chemical purge done at least once in 720 min (=12 hours). In applications where the chemical exposure is not likely, the interval can be longer.
Type PUR and press Enter to proceed. The maximum interval is 14400 minutes (=10 days).
Example:
>pur
Interval Purge : OFF ?
Interval : 720 min ?
Power-up Purge : OFF ?
Duration : 240 s ?
Settling : 240 s ?
Temperature : 180 'C ?
>
CAUTION Do not modify the Duration, Settling, and Temperature settings unless instructed to do so. The sensor element may be permanently damaged from overheating.
NOTE
NOTE
To activate the new interval settings immediately, reset the probe.
When chemical purge in power-up is enabled, wait about 6 min after power-up before taking measurements. The output channels are locked for the first operation minutes to the initial measured values.
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Sensor Heating
This function is optionally available only in probes with
HUMICAP ®
180RC or HUMICAP ®
180C composite sensors. It should be used only with the heated probe.
The sensor heating is recommended for the high humidity environments where even small temperature differences can cause water to condense on the sensor. The sensor heating speeds up the recovery of the humidity sensor from condensation.
Sensor heating starts-up when the relative humidity of the measuring environment reaches the RH-value set by a user (RH-limit). You can define the RH-sensor heating temperature as well as the duration of the heating.
After the heating cycle, the humidity conditions are checked and new sensor heating is performed if the predefined conditions are reached again.
NOTE During the sensor heating, the outputs are locked to the values measured before the heating cycle.
Setting Humidity Sensor Heating
When the HMP155 leaves the factory, the sensor heating follows the factory default values. You can enable or disable the function, change the
RH-limit and define the heating temperature and duration of this function.
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NOTE
XHEAT
Enables or disables the sensor heating.
Example:
>xheat on
Extra heat : ON
>xheat off
Extra heat : OFF
>
To configure the sensor heating, use the XHEAT command without parameters. Enter the values after the question mark. The available ranges include the following:
0 ... 100 %RH (default: 95 %RH) Extra heat RH -limit (heating function starts-up above the setpoint)
Extra heating temperature
Extra heating time
0 ... 200 ºC (default: 100 ºC)
0 ... 255 s (default: 30 s)
To see the current values, use the XHEAT * command.
Example :
>xheat *
Extra heat : OFF
RH limit : 95 %RH
Temperature : 100 'C
Duration : 30 s
>
After the defined XHEAT duration, there is an additional cooling time of
10 seconds before outputs are updated.
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Chapter 5 ______________________________________________________________ Maintenance
CHAPTER 5
MAINTENANCE
This chapter contains information that is needed in basic maintenance of the product.
Periodic Maintenance
Cleaning
Clean the probe with a soft, lint-free cloth moistened with mild detergent.
Changing the Probe Filter
In the course of time the probe filter will be contaminated with matter that you cannot remove by cleaning. When this happens, the HMP155 response time becomes longer and measurement accuracy decreases. You need to replace the probe filter with a new one:
1. Remove the filter from the probe.
2. After removing the filter, check the O-ring and change it if
necessary. See Figure 12 on page 53.
3. Install a new filter on the probe.
New filters can be ordered from Vaisala, see section Options and
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NOTE
Changing the Sensor
You can change the HUMICAP
®
sensor yourself and the probe does not have to be sent in for service for a sensor change.
Both HUMICAP
®
180 and HUMICAP
®
180R sensors can be changed, but you must never replace a HUMICAP
®
180 sensor with a
HUMICAP
®
180R sensor or vice versa.
To change the sensor:
1. Remove the filter from the probe. See the instructions in section
Changing the Probe Filter on page 51.
2. After removing the filter, check the O-ring and change it if
necessary. See Figure 12 on page 53.
3. Remove the damaged sensor and insert a new one. Handle the new sensor by the plastic socket. DO NOT TOUCH THE SENSOR
PLATE.
4. After sensor change the humidity calibration must be done
according to the instructions, see section Relative Humidity
Adjustment after Sensor Change on page 65.
5. Attach a new filter on the probe.
CAUTION In HUMICAP
®
180C/180RC models, the temperature sensor is integrated with the relative humidity sensor. It is recommended that these type of
sensors are changed by Vaisala Service. See section Product Returns on page 55.
If you do change the sensor yourself, the instructions above apply, except now before removing the damaged sensor, you need to unsolder the connections from the temperature sensor pins. Likewise the new temperature sensor connections need to be soldered to the temperature sensor pins. Be careful when soldering the sensor pins.
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0802-159
Figure 12 Changing the HUMICAP
®
180/180R Sensors
The following numbers refer to Figure 12 above:
1 = Filter
2 = O-ring
3 = HUMICAP
®
sensor
4 Pt100 temperature sensor
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Error States
In an error state, the quantity is not measured and the output is shown as follows:
- Analog channel outputs 0 V (you can use the AERR serial line
command to change this fault indication value, see section AERR on page 43).
- The serial port outputs stars (***) instead of measured values.
You can also check the error message via the serial interface by using the
ERRS command. In case of constant error, please contact Vaisala, see
sections Technical Support and Product Returns on page 55 .
NOTE If you do not know the HMP155 serial connection settings, you can force
the settings 19200 N 8 1 with the # command. The # command is only
available in the first three seconds after power-up.
The possible error messages of HMP155 are listed in Table 15 below.
Table 15 Error Messages
Error Message Description
T MEAS error
T REF error
TA MEAS error
Error in temperature measurement
Error in temperature measurement
Error in T-probe measurement
TA REF error
F MEAS error
Error in T-probe measurement
Error in humidity measurement
F REF1 error
F REF3 error
Error in humidity measurement
Error in humidity measurement
Internal error Program flash checksum error
Parameter flash checksum error
Internal error
INFOA checksum error Internal error
Internal error SCOEFS checksum error
Action
Check the HUMICAP
® sensor.
Contact Vaisala Service
Check the additional temperature probe.
Contact Vaisala Service
Check the HUMICAP
® sensor.
Contact Vaisala Service
Contact Vaisala Service
Contact Vaisala Service
Contact Vaisala Service
Contact Vaisala Service
Contact Vaisala Service
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Chapter 5 ______________________________________________________________ Maintenance
Technical Support
For technical questions, contact the Vaisala technical support by e-mail at [email protected]
. Provide at least the following supporting information:
- Name and model of the product in question
- Serial number of the product
- Name and location of the installation site
- Name and contact information of a technically competent person who can provide further information on the problem.
Product Returns
If the product must be returned for service, see www.vaisala.com/returns .
For contact information of Vaisala Service Centers, see www.vaisala.com/servicecenters .
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Chapter 6 ___________________________________________________Calibration and Adjustment
CHAPTER 6
CALIBRATION AND ADJUSTMENT
NOTE
NOTE
The Vaisala HUMICAP
®
Humidity and Temperature Probe HMP155 is fully calibrated and adjusted as shipped from factory. Recommended calibration interval is one year. Depending on the application, it is good to make more frequent checks. Calibration must always be done when there is reason to believe that the device is not within the accuracy specifications.
It is recommended that calibration and adjustment is carried out by
Vaisala. See section Product Returns on page 55.
Calibration and adjustment can also be carried out either by using the buttons on the probe or through the serial line connection.
Vaisala recommends that RH adjustment is carried out as a two-point adjustment. With one-point adjustment, the required accuracy can only be achieved if the actual measurement environment (RH and T) is the same as the one-point adjustment environment.
Before attempting calibration, the ADJ button has to be held down until a green LED lights up. This turns off the heating and the additional temperature probe in the case you are using an HMP155 with either of those options. After that HMP155 is ready to be checked and calibrated.
Because the T-probe is turned off during calibration, it does not need to be inserted into the same reference conditions with the humidity probe.
If a chemical purge option is available, it should always be carried out before calibration.
Button calibration is not available for the additional temperature probe.
In the passive output version of HMP155, the temperature cannot be calibrated.
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0801-076
Figure 13 HMP155 Adjustment Buttons
The following numbers refer to Figure 13 above:
1 = Protective cover (unscrewed)
NOTE
NOTE
5 = Protective plug (lifted up)
There is a two-color indicator LED located under the protective plug and
next to the Down button, see Figure 13 above. The LED is green and red.
If you are using a warmed probe (HMP155 active output version option), probe heating will be interrupted when ADJ button is pressed, see
Figure 13 above. Allow sufficient time for the probe to reach ambient
temperature before starting the adjustment procedure.
Fixed pressure compensation value of 1.01325 bar is used when in adjustment mode.
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Push-Button Calibration
Calibration and adjustment of the HMP155 can be done by using the adjustment buttons found on the probe. The two-point humidity adjustment is carried out by using two relative humidity references: for example saturated salt points 11 % RH (LiCl) and 75 % RH (NaCl). The difference between the two humidity reference points must be at least 30
%RH. The difference between the two temperature reference points must be at least 30 °C.
NOTE In push-button calibration, the probe outputs are by default relative humidity in the range 0…100 %RH in CH1 and temperature in the range
-40…+60°C in CH2.
NOTE
NOTE
Two-Point Humidity and Temperature
Adjustment
To make a humidity or temperature adjustment:
1.
Carry out the chemical purge (if available). See section Chemical
2. Uncover the adjustment buttons on the probe by removing the protective cover and removing the calibration seal.
3. Open the protective plug and you can see three buttons marked -, □
and +. There is also a two-colored indicator LED. See Figure 13 on page 58.
the button and hold it down until the green indicator
LED lights up. This puts HMP155 in RH calibration mode.
5. Remove the filter and insert the probe into a measurement hole of the dry end reference chamber (for example, LiCl: 11 % RH) to do the low humidity offset adjustment.
Do not touch the adjustment buttons before the conditions have stabilized. This takes approximately 30 minutes.
and + buttons, make sure the A out
voltage is correct and press the ADJ button. Green indicator LED turns off and back on.
Do not touch the adjustment buttons before the conditions have stabilized.
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NOTE
NOTE
7. Insert the probe into the high end reference chamber (for example,
NaCl: 75 % RH chamber in the humidity calibrator HMK15) and do the high humidity gain adjustment by using the - and + buttons to make sure the A out
voltage is correct. To finish the RH calibration, press the ADJ button and the red indicator LED lights up.
If you do not wish to perform the temperature adjustment at this time, press ADJ -button two times and the indicator LED turns off. After reset, HMP155 exits the calibration mode. Otherwise, continue following the instructions from step 8 onwards.
8. Insert the probe into a known reference temperature (if HMK15
Humidity Calibrator is not used) and let the temperature reading stabilize.
Do not touch the adjustment buttons before the conditions have stabilized.
NOTE
NOTE by making sure the A out
voltage is correct and press the ADJ button. Red indicator LED turns off and back.
If you do not wish to perform the two-point temperature adjustment at this time, press the ADJ button one more time so that the red indicator
LED turns off. After reset, HMP155 exits the calibration mode.
Otherwise, continue following the instructions from step 10 onwards.
10. Insert the probe into another reference temperature.
Do not touch the adjustment buttons before the conditions have stabilized. by making sure the A out
voltage is correct. the button and the red indicator LED turns off.
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Chapter 6 ___________________________________________________Calibration and Adjustment
NOTE
NOTE
One-Point Humidity and Temperature
Adjustment
To make a one-point humidity or temperature adjustment:
1.
Carry out the chemical purge (if available). See section Chemical
2. Uncover the adjustment buttons on the probe by removing the protective cover and removing the calibration seal.
3. Open the protective plug and you can see three buttons marked -, □
and +. There is also a two-colored indicator LED. See Figure 13 on page 58.
4. Remove the filter and insert the probe into a measurement hole of the salt chamber to do the humidity adjustment. the button and hold it down until the green indicator
LED lights up. This puts HMP155 in RH calibration mode.
Do not touch the adjustment buttons before the conditions have stabilized. the out
voltage is correct and press the ADJ button. Green indicator LED turns off and back on.
7. To move on to the temperature adjustment, press the ADJ button once and the red indicator LED lights up.
8. Insert the probe into the reference temperature.
Do not touch the adjustment buttons before the conditions have stabilized. by making sure the A out
voltage is correct and press the
ADJ button. Red indicator LED turns off and back on. the button one more time so that the red LED turns off to indicate the probe has quit the calibration mode.
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Passive Output Version Push-Button
Calibration
If you are operating a passive output version HMP155, the humidity calibration is carried out similarly to calibration of the active output version. After finishing the humidity adjustment, press the ADJ button twice until the LED turns off. Reset the probe to exit the calibration mode.
62 _______________________________________________________________ M210912EN-C
Chapter 6 ___________________________________________________Calibration and Adjustment
Serial Line Calibration
Two-Point Humidity Adjustment
Note that the difference between the two humidity references must be at least 30 %RH.
To make a humidity adjustment:
1.
Connect the HMP155 to a PC. See section Serial Line
Communication on page 24. Open a terminal program.
2.
Carry out the chemical purge (if available). See section Chemical
the button and the green LED lights up.
4. Remove the filter from the probe and insert the probe into a measurement hole of the dry end reference chamber (for example,
LiCl: 11 % RH). the command and press ENTER.
6. Wait at least 30 minutes for the sensor to stabilize.
7. Press a few times to check if the reading has stabilized.
8. When the reading has stabilized, give the reference humidity after the question mark and press ENTER.
>crh
RH : 16.6675 1. ref ?
RH : 16.4978 1. ref ?
RH : 16.3956 1. ref ? 11.25
Press any key when ready ...
RH : 11.25 Ref2 ?
9. Now the device is waiting for the high end reference. Insert the probe into the measurement hole of the high end reference chamber
(for example, NaCl: 75 % RH chamber in the humidity calibrator
HMK15). Press any key when ready.
10. Let the probe stabilize for about 30 minutes. You can follow the stabilization by pressing ENTER.
11. When stabilized, type the high end reference value after the question mark and press ENTER.
RH : 75.45 Ref2 ?
RH : 75.57 Ref2 ?
RH : 75.55 Ref2 ?
RH : 75.59 Ref2 ? 75.5
OK
12. OK indicates that the adjustment has succeeded and the new calibration coefficients are calculated and stored.
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13. Enter the adjustment information (date and text) to the memory of the probe; see the commands CTEXT and CDATE.
14. Reset the probe with the RESET command.
15. Take the probe out of the reference conditions and replace the filter.
NOTE
Two-Point Temperature Adjustment
In the passive output version of HMP155, the temperature cannot be calibrated.
Note that the difference between the two temperature references must be at least 30 ºC. The additional temperature sensor is suitable for calibration in liquid bath.
To make a temperature adjustment: the button to enable the adjustment mode. This lights up the green LED on the probe. If using a warmed probe for measuring, probe heating will be interrupted when ADJ button is pressed.
2. Wait some time for the probe to reach ambient temperature. the command (or CTA for additional T-probe) and press
ENTER .
4. Press a few times to check if the reading is stabilized. Let the reading stabilize, give the reference temperature after the question mark and press ENTER three times.
Example (2-point adjustment):
>ct
T : 18.6038 1. ref ?
T : 18.6068 1. ref ?
T : 18.6098 1. ref ? 19.0
Press any key when ready ...
T : 49.5176 2. ref ? 50.0
OK
>
5. Move the probe into another reference temperature and let the reading stabilize. Give the reference temperature after the question mark and press ENTER, see example above.
6. OK indicates that the calibration has succeeded.
7. Enter the calibration information (date and text) to the probe's memory; see the serial commands CTEXT and CDATE.
8. Reset the probe with RESET command.
64 _______________________________________________________________ M210912EN-C
Chapter 6 ___________________________________________________Calibration and Adjustment
Relative Humidity Adjustment after
Sensor Change
After sensor change, carry out the procedure as described in previous sections. Just replace the CRH command with the FCRH command.
FCRH
Example :
>fcrh
RH : 25.19 Ref1 ? 11.3
Press any key when ready ...
RH : 70.02 Ref2 ? 75.5
OK
>
The
OK
indicates that the calibration has been successful.
One-Point Humidity and Temperature
Adjustment
One-point humidity and temperature adjustment can be done by using the following serial line commands:
- CRH and FCRH commands for humidity adjustment
- CT and CTA commands for temperature adjustment
To make an adjustment, just enter the command , press space bar and then enter the reference value, as in the example below.
Example :
Crh 20.0
OK
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User Adjustment Commands
You can use the user adjustment commands to display and set parameters. You can only use LI command in ADJUST mode.
These parameters are updated with the commands CRH, CT, and CTA.
L
With the L command you can display user adjustment parameters.
Example:
>l
Cp offset : 0.00000000E+00
Cp gain : 1.00000000E+00
T offset : 0.00000000E+00
T gain : 1.00000000E+00
Ta offset : 0.00000000E+00
Ta gain : 1.00000000E+00
>
NOTE
LI
With the LI command you can display and ask for new values for the user adjustment parameters.
Example:
>li
Cp offset : 0.00000000E+00 ?
Cp gain : 1.00000000E+00 ?
T offset : 0.00000000E+00 ?
T gain : 1.00000000E+00 ?
Ta offset : 0.00000000E+00 ?
Ta gain : 1.00000000E+00 ?
>
If you suspect that something has gone wrong with the calibration, you can use the LI command to return the factory values by entering the values shown in the example above.
Feeding Adjustment Information
The information added with the serial line commands below is shown in the device information fields. You can only use CTEXT and CDATE
66 _______________________________________________________________ M210912EN-C
Chapter 6 ___________________________________________________Calibration and Adjustment commands in ADJUST mode. To put HMP155 in adjustment mode, just hold down the ADJ button until the green LED lights up.
CTEXT
Use the CTEXT command to enter text to the adjustment information field.
Example:
>ctext
Cal. info : Helsinki / FIN ? Finland
>
CDATE
Use the CDATE command to enter date to adjustment information field.
Set the adjustment date in format YYYYMMDD.
Example:
>cdate 20080320
>
Analog Output Adjustment
In the analog output calibration the analog output is forced to the following values:
- Voltage output: 10 % and 90 % of the range
Connect HMP155 to a calibrated voltage meter in order to measure voltage.
NOTE Hold down the ADJ button until a green LED lights up. This puts the
HMP155 in ADJUST mode.
NOTE The serial line command ACAL cannot be used with HMP155 passive output version.
Enter the ACAL command and type the multimeter reading for each case. Continue by pressing ENTER. When a channel is specified, only the specified analog output channel is adjusted.
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ACAL [0/1]
Example :
Ch 0:
>acal 0
U1 ( V ) ? 1.001
U2 ( V ) ? 9.011
Ch 1:
>acal 1
U1 ( V ) ? 2.0988
U2 ( V ) ? 8.8997
>
MI70 Check and Adjustment
Vaisala MI70 measurement indicator is an optional accessory that can be used as a display or as a communication device for HMP155. When it is used, HMP155 is powered via MI70.
NOTE
With MI70 you can check the HMP155 easily on the field. Both the active output version and the passive output version (only RH displayed) can be checked with MI70.
In the active output version relative humidity, temperature and additional
T-probe temperature can be calibrated. In the passive output version, only relative humidity calibration is possible.
To check and adjust HMP155 with MI70:
1. Connect HMP155 to MI70 by using a connection cable (Vaisala item 221801).
2. Turn MI70 on by pressing the power key and follow the instructions given on the display.
When turning on the passive output version, always hold down the ADJ button simultaneously.
3. Activate the adjustment mode by holding down the ADJ button on the probe until the message below appears on the MI70 display.
68 _______________________________________________________________ M210912EN-C
Chapter 6 ___________________________________________________Calibration and Adjustment
4. Press to move on to the adjustment and select the quantity you want to adjust. The list of quantities displayed in the figure below varies according to the configuration of your HMP155.
5. Follow the instructions given on the display to finish the adjustment.
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70 _______________________________________________________________ M210912EN-C
Chapter 7 ____________________________________________________________ Technical Data
CHAPTER 7
TECHNICAL DATA
This chapter provides the technical data of the product.
Performance
Relative Humidity
Table 16 Relative Humidity Performance
Description Value
Measurement range 0 ... 100 %RH
Accuracy (including non-linearity, hysteresis and repeatability) at +15 ... 25 °C (59 … 77 °F) ±1% RH (0 ... 90% RH)
±1.7% RH (90 ... 100% RH) at -20 … +40 °C (-4 … 104 °F) at -40 ... -20 °C (-40 … -4 °F) at +40 … +60 °C (104 … 140 °F) at -60 ... -40 °C (-76 … -40 °F)
Factory calibration uncertainty
(+20 °C)
±(1.0 + 0.008 × reading)% RH
±(1.2 + 0.012 × reading)% RH
±(1.2 + 0.012 × reading)% RH
±(1.4 + 0.032 × reading)% RH
±0.6% RH (0 ... 40% RH)
±1.0% RH (40 ... 97% RH)
Recommended humidity sensor
HUMICAP
®
180R
HUMICAP
®
180RC for typical applications for applications with chemical purge and/or warmed probe
Response time for HUMICAP
®
180R(C) at 20 °C in still air with sintered PTFE filter
1
Defined as ± 2 standard deviation limits. Small variations possible, see also calibration certificate.
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Temperature
Table 17 Temperature Performance
Description Value
Measurement range
Accuracy with voltage output at -80 … +20 °C at +20 … +60 °C
-80 ... +60 °C (-112 ... +140 ºF)
±(0.226 - 0.0028 x temperature) °C
±(0.055 + 0.0057 x temperature) °C
Accuracy with passive (resistive) output
According to IEC 751 1/3
Class B
±(0.1 + 0.00167 x |temperature|) °C
Accuracy with RS-485 output (see Figure 14 below)
at -80 … +20 °C ±(0.176 - 0.0028 x temperature) °C at +20 … +60 °C
Temperature sensor(s)
±(0.07 + 0.0025 x temperature) °C
Pt 100 RTD Class F 0.1 IEC 60751
Response time (63%) for additional temperature probe in 3 m/s air flow
63% < 20 s
90% < 35 s
0804-032
Figure 14 Accuracy over Temperature Range: Voltage and RS-
485
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Chapter 7 ____________________________________________________________ Technical Data
Operating Environment
Table 18 Operating Environment
Description Value
Operating temperature range for humidity measurement
Storage temperature range
Electromagnetic compatibility
-80 ... +60 °C (-112 ... +140 °F)
-80 ... +60 °C (-112 ... +140 °F)
Complies with EMC standard
EN61326-1, Electrical equipment for measurement control and laboratory use - EMC requirements for use in industrial locations.
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Calculated Variables
Table 19 Calculated Variables
Quantity Abbreviation Metric Unit Non Metric
Unit
Dew point / Frost point TDF ºC ºF
Temperature (T d/f
)
Dew point Temperature (T d
) TD
Mixing ratio (x) X
ºC g/kg
ºF gr/lbs.
Wetbulb temperature (T w
) TW ºC ºF
Accuracies of Calculated Variables
Accuracies of the calculated variables depend on the calibration accuracy of the humidity and temperature sensors; here the accuracies are given for ± 2 %RH and ± 0.2 °C.
Accuracy of Dew point Temperature °C
-40 1.86
-20 2.18
0
20 2.87
40 3.24
60 3.60
Accuracy of Mixing Ratio g/kg (Ambient
Pressure 1013 mbar)
-40 0.003 — —
-20 0.017 — —
0
20 0.31
40 0.97
60 2.68
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Chapter 7 ____________________________________________________________ Technical Data
Accuracy of Wet Bulb Temperature °C
-40 0.20
-20 0.21
0
20 0.45
40 0.84
60 1.45
Accuracy of Dew point Measurement
Find the intersection of the dew point temperature curve and the dew point difference reading (process temperature-dew point temperature) on the x-axis and read the accuracy in dew point measurement on the y-axis.
0508-017
Figure 15 Accuracy of Dew point Measurement
Inputs and Outputs
Table 20 Outputs
Description Value
Voltage output
Resistive Pt100 4-wire connection
0 ... 1 V, 0 ... 5 V, 0 ... 10 V
RS-485
Minimum operating voltages
0…5 V output
0…10 V output, probe heating, chemical purge or XHEAT
12 V
16 V
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Table 21 Average current consumption
(+15 VDC, load 100 kOhm)
Description Value
0…1 V output
0…10 V output
RS-485
During chemical purge
With warmed probe
< 3 mA
+ 0.5 mA
< 4 mA max. 110 mA max. 150 mA
Table 22 Operating Voltage and Settling Time
Description Value
Operating voltage
Settling time at power-up
Voltage output
7 ... 28 VDC
2 s
Mechanics
Table 23 Mechanical Specifications
Description Value
User cable connector
Connection cable lengths
Cable coating
Max wire size
Additional temperature probe cable length
M12 series 8-pin connector (male)
3.5 m, 5 m, 10 m or 30 m
PUR
AWG 26
2 m
Additional temperature probe material Stainless steel (AISI 316L)
USB service cable USB connection cable 1.45 m
MI70 service cable
(Item 221040)
MI70 connection cable (Item 221801)
PC plastic
IP66
Housing material
Housing classification
Weight
3.5 m cable
30 m cable
159 g
1260 g
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Chapter 7 ____________________________________________________________ Technical Data
Options and Accessories
Table 24 Options and Accessories
SENSORS
HUMICAP180R HUMICAP180R
HUMICAP180 HUMICAP180
HUMICAP180RC HUMICAP180RC
HUMICAP180C HUMICAP180C
FILTERS
Sintered Teflon Filter + O-ring
Membrane Filter
219452SP
230727SP
PROBE MOUNTING ACCESSORIES
T-probe Installation Adapter for
DTR13
221069
T-probe Installation Adapter for
DTR502
HMP155 and T-probe Installation
Adapter for Stevenson Screen
221072
221321
CONNECTION CABLES
Powering USB Cable for Service
MI70 Connection Cable
221040
221801
Connection Cable 3.5m 8-pin M12 220496
Connection Cable 5m 8-pin M12
Connection Cable 10m 8-pin M12
223283
220497
220498 Connection Cable 30m 8-pin M12
OTHER
Protection Set for Calibration Buttons: protective cover, 2 O-rings and protective plug
221318
HMK15 Humidity Calibrator with mercury thermometer
HMK15 Humidity Calibrator with a thermometer with red capillary liquid
HMK15 Adapter Fitting for 12 mm
Probes
Connection cover for enhanced protection
19729HM
25130HM
211302SP
DRW236638
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Dimensions in mm (inches)
HMP155 Probe
279 [10.98]
266 [10.47]
20 [0.79]
Ø12 [0.47]
86 [3.39]
24 [0.94]
Figure 16 Probe Dimensions
Additional Temperature Probe
0801-077
Figure 17 Additional Temperature Probe Dimensions
0801-078
78 _______________________________________________________________ M210912EN-C
Appendix A ______________________________________________________ Calculation Formulas
APPENDIX A
CALCULATION FORMULAS
This Appendix contains the formulas used for the calculated output quantities.
The HMP155 series probe measures relative humidity and temperature.
From these values dew point and frost point, mixing ratio, wet bulb temperature, absolute humidity and enthalpy in normal pressure are calculated using the following equations:
Dew point/frost point:
T d / f
237 .
3
7 .
5
10 log
P w
6 .
1078
1
273 .
15
P w
is the water vapor pressure. Dew point/frost point is measured in
Kelvin.
Mixing ratio:
(1) x
621 .
99
P w p P w
Absolute humidity:
(2)
A
C
P w
T where
C = 216.679
(3)
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Enthalpy: h
T
( 1 .
01
0 .
00189
x )
2 .
5
x (4)
The water vapor saturation pressure at temperature T pws
is calculated over water and over ice by using four equations (5-8). These formulas are taken from Hyland, R.,Wexler, A.:Formulations of the Thermodynamic
Properties of the Saturated Phases of H2O from 173.15 K to 473.15 K,
Ashrae transactions 1983, Part 2A. pp. 500-513.
PWS over water:
T
i
3
0
C i
T pws i
PWS over ice:
T pws
(5)
(6) where:
T pws
= temperature K
Ci = coefficients
C0 = 0.4931358
C1 = -0.46094296 * 10-2
C2 = 0.13746454 * 10-4
C3 = -0.12743214 * 10-7
Over water:
100
ln P wsWATER
b
1
b
3
0 b i
i b
4 ln
Over ice:
100
ln P wsICE
a
1
b
4
0 a i
i a
6 ln
where:
bi = Coefficients over water
b-1 = -0.58002206 * 104
(7)
(8)
80 _______________________________________________________________ M210912EN-C
Appendix A ______________________________________________________ Calculation Formulas where:
b0 = 0.13914993 * 101
b1 = -0.48640239 * 10-1
b2 = 0.41764768 * 10-4
b3 = -0.14452093 * 10-7
b4 = 0.65459673 * 101 a i
= Coefficients over ice
a-1 = -0.56745359*
101
a1 = -0.96778430*
10-6
a3 = 0.20747825*
10-12
a6 = 0.41635019*
The water vapor pressure is calculated using:
P w
RH
P ws
100
Parts per million by volume is calculated using: ppm v
10
6
p
P w
P w
Symbols:
T d
= dew point temperature (°C)
P w
= water vapor pressure (hPa)
P ws
= water vapor saturation pressure (hPa) x = mixing ratio (g/kg) p = atmospheric pressure (hPa)
A = absolute humidity (g/m3)
T = temperature h = enthalpy
(9)
(10)
VAISALA _______________________________________________________________________ 81
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