C101-E115

C101-E115
C101-E115
UV
Talk Letter
Vol.3
November 2009
U
V
Talk
Vol.3
UV Talk Letter
Novem
Letter
ber 20
Monochromators
09
In this volume, we will describe the monochromator, an important part of the spectrophotometer that was
explained in UV TALK LETTER Vol. 2 "The Structure of a Spectrophotometer".
Light containing various wavelengths can be broken down
according to the wavelength. White light (containing many
wavelengths) entering the monochromator is extracted as
green (540 nm), red (650 nm), or some other monochromatic
(single-wavelength) light. The operating principle can be
explained by an experiment using a prism to break down
sunlight, as shown in Fig. 2. A slit can be inserted in the
rainbow to extract monochromatic light. Fixing the slit and
rotating the prism rotates the direction of the rainbow such that
the color of the extracted monochromatic light changes.
Breaking down light into its constituent wavelengths similar to
a rainbow is known as "dispersion," and an element with this
property is called a "dispersive element." The prism is a typical
dispersive element. Another one is the diffraction grating.
White light shining onto a diffraction grating reflects back in
rainbow colors, as shown in Fig. 3. White light reflecting in
rainbow colors from the surface of a CD is a result of the same
dispersion phenomenon as the diffraction grating. In the same
way as a prism, the diffraction grating can be rotated to
change the color of the light extracted through the slit.
Light source
Monochromator
Sample
compartment
Detector
Fig.1 Construction of a Spectrophotometer
Sunlight
(white light)
Monochromatic
light
Rotation
Prism
Slit
The monochromator comprises a dispersive element, an
entrance slit and mirrors to create a parallel beam similar to
sunlight, and an exit slit and mirrors to extract the
monochromatic light.
Fig.2 Prism Experiment
1.Dispersive Element
The prism and diffraction grating are typical dispersive
elements. Table 1 shows their respective features. Due to their
superior dispersion properties, diffraction gratings are often
used in modern spectrophotometers. The prism achieves
dispersion due to the difference in the material refractive index
according to the wavelength. However, the diffraction grating
uses the difference in diffraction direction for each wavelength
due to interference.
The reflective blazed diffraction grating that is commonly used
in spectrophotometers is described below.
Sunlight
(white light)
Rotation
Monochromatic
light
Diffraction grating
Slit
Fig.3 Using a Diffraction Grating
2
UV Talk Le t t e r Novem be r 2 0 0 9
The diffraction gratings we study at high school are often a row
of slits, as shown in Fig. 4. However, the reflective blazed
diffraction grating has a sawtooth cross-section, as shown in
Fig. 5. As light that passed through an adequately fine slit is
diffracted, light reflected from an adequately fine sawtooth
surface is also diffracted. There are 500 to 2000 serrations per
millimeter.
The sawtooth face of a commercially produced diffraction
grating is the replica of a master grating. A thin synthetic-resin
replica is stuck onto a glass sheet and coated with aluminum.
The master was traditionally produced using a machine tool,
but now the surface is formed by an ion beam or using laser
beam photolithography. A smooth surface reduces stray light
(light at unwanted wavelengths).
This is the basic expression governing diffraction gratings:
mλ=d (sin i + sinθ) ... (1)
Where, d is the groove (serration) spacing, i is the angle of
incidence, θ is the diffraction angle (positive if the incident
light and diffracted light are on the same side of the normal to
the diffraction grating surface, negative if they are on opposite
sides of the normal), λ is the wavelength, and m is the order
(see Fig. 6). This means that when d, m, and i are fixed, light
of wavelength λ is diffracted in direction θ.
Expression (1) indicates the presence of higher-order light. If
d, i, and λ are fixed in expression (1), a different value of m
results in a different value of θ. This indicates that light of
wavelength λ diffracts in multiple angles θ, as shown in Fig. 7.
These light directions are named using a combination of the m
value and the + or - sign, such as +1st-order light or -1st-order
light. Incidentally, the light when m=0 is known as zero-order
light, for which the diffraction angle θ is equal to the angle of
incidence i. This is reflected as white light, equivalent to
normal specular reflection.
Prism
Reflective Diffraction Grating
Dispersion
Principle
Exploits differences in the
material refractive index
according to the wavelength.
Exploits diffraction from
a reflective surface with
a regular grating structure.
Light
Utilization
Efficiency
High
(Generally has high efficiency
despite light losses from
boundary reflection and
absorption during transmission
through the material. A single
prism covers the range from
185 to 2500 nm.)
Low
(Light with the same
wavelength is dispersed
in several directions as
higher-order light.
High efficiency near the
blaze wavelength.)
Wavelength
Dependency
of Dispersion
Variable. High for UV;
low for visible to NIR light.
High and approximately
constant.
Temperature
Dependency
of Dispersion
High
(Effects of temperature on
refractive index.)
Low
(Deformation due to
temperature.)
HigherOrder Light
None
Yes
(Requires higher-order
light cutout filter.)
Stray Light
Low
High
(Dispersion due to
higher-order light and
surface roughness.
Modern diffraction gratings
achieve comparatively
low stray light.)
Polarization
Low
High
Table 1 Comparison of Prism and Grating
( : advantageous for spectrophotometer)
The various light orders of a diffraction grating result in
dispersion of the energy and a reduction in light utilization
efficiency. However, the diffracted light energy from a
diffraction grating with a fine sawtooth profile is concentrated
in the direction of the specular reflection, as shown in Fig. 8.
This wavelength is known as the "blaze wavelength." The
diffraction grating in a spectrophotometer is normally used
near the blaze wavelength. However, multiple diffraction
gratings can be used separately to increase the efficiency
over a wide range of wavelength.
Fig.4 Diffraction Grating with Row of Slits
A different way of viewing the phenomenon of higher-order
light is to say that, if d, i, and θ are fixed in expression (1), a
different value of m results in a different λ. This indicates that
light of multiple wavelengths θ diffracts in diffraction angles λ,
as shown in Fig. 9. Therefore, a higher-order light cutout filter
(short-wavelength cutout filter) is positioned after the
monochromator exit slit to extract light at a specific
wavelength (normally ±1st-order light).
Aluminum
Diffraction grating
Synthetic resin
Glass
Diffraction grating
Fig.5 Reflective Blazed Diffraction Grating
3
Monochromators
2nd-order light 1st-order light
(wavelength λ) (wavelength λ)
0-order light
(white light)
Grating normal
θ
i
Incident light
Diffracted light
(wavelength λ)
i
-1st-order light
(wavelength λ)
i
Incident light
(white light)
d
Fig.6 Basic Expression Governing Diffraction Gratings
Fig.7 Higher-Order Light
1st-order light
(wavelength λ)
Normal to sawtooth surface
Incident light
Diffracted light
(blaze wavelength)
Incident light
i
θ
2nd-order light
(wavelength λ/2)
3rd-order light
(wavelength λ/3)
Fig.8 Blaze Wavelength
Fig.9 Higher-Order Light (2)
2. Mountings (Aligning Elements)
The basic elements of a monochromator are (1) entrance slit,
(2) collimating mirror (to form a parallel beam after the slit), (3)
diffraction grating (dispersive element), (4) camera mirror
(focuses light from the dispersive element onto the exit slit),
and (5) exit slit (see Fig. 10). In Fig. 2 and Fig. 3 a simple exit
slit can extract the required wavelength, as the light beam
incident on the dispersive element is narrow. A camera mirror
is required in an actual monochromator, however, as light is
incident over the entire surface of the dispersive element. This
involves refocusing the image of the (1) entrance slit at the
position of (5) exit slit at the wavelength to be extracted. The
other wavelengths either miss (4) camera mirror or focus at
some position away from (5) exit slit. Typical mountings used
in spectrophotometers are the Littrow mount, Czerny-Turner
mount, and concave mounts such as the Seya-Namioka mount.
As shown in Fig. 11, the Littrow mount comprises a single
spherical mirror or off-axis parabolic mirror that acts as the
collimating mirror and camera mirror. The Czerny-Turner mount
uses two symmetrically arranged spherical mirrors as the
collimating mirror and camera mirror, as shown in Fig. 10.
A concave mount uses a curved diffraction grating that offers
both dispersion and focusing functions to simplify the
construction, as shown in Fig. 12. This mount is used to
reduce the number of mirrors where extreme resolution is not
required.
4
(1) Entrance slit
(2) Collimating mirror
(3) Diffraction grating
(4) Camera mirror
(5) Exit slit
Fig.10 Basic Elements of a Monochromator
(Czerny-Turner Grating Monochromator)
UV Talk Le t t e r Novem be r 2 0 0 9
3. Resolution
We described above how a monochromator acts to product
monochromatic (single-wavelength) light from white light.
However, while it is called single-wavelength light, it covers a
certain range of wavelengths. For example, 540 nm light may
extend from 539.5 to 540.5 nm. Consequently, when this light
is used for measurements, information for the range from 539.5
to 540.5 nm is mixed together. This light is called "1 nmbandwidth light" and this monochromator is said to have 1 nm
resolution. The smaller the wavelength band, the better the
resolution. Fig. 13 shows how the resolution and bandwidth are
defined as the peak width at half maximum (PWHM).
Diffraction grating
Entrance
slit
Spherical mirror or
off-axis parabolic mirror
Exit slit
Once the monochromator elements and their positions are
fixed, the resolution is determined by the slit width. As the light
disperses as a rainbow, increasing the exit slit width reduces
the resolution. A wider entrance slit results in a larger image at
the exit slit position, such that the image for the wavelengths
adjacent to the target wavelength enters the exit slit and
reduces the resolution.
A diffraction grating has its own inherent resolution, which is
determined by the diffraction principle according to the
number of gratings. The improvement in monochromator
resolution possible by reducing the slit width is limited due to
this diffraction grating resolution, the aberration of the overall
optical system, and mirror imperfections.
The monochromator slit width used in a spectrophotometer is
expressed not as the slit width dimension but as the value of
the resolution achieved. Setting the slit width to 1 nm, sets the
monochromator resolution to 1 nm, such that 1 nm-bandwidth
light shines onto the sample.
Fig.11 Littrow Grating Monochromator
Entrance slit
Exit slit
For measurements by spectrophotometer, the optimal
resolution is determined by the spectral shape of the sample.
A slightly larger slit width increases the light intensity reaching
the detector and reduces the data noise but results in poorer
resolution. Originally sharp spectral peaks broaden as shown
in Fig. 14. A narrow slit width achieves a spectrum shape
closer to the original spectrum. For example, if the original
spectrum has a peak waveform, setting the slit width to
between 1/8 and 1/10 the PWHM results in a measured peak
with at least 99% the original height. 1)
However, if the aim is not to determine the spectrum shape
itself but to conduct concentration measurements using a
calibration curve, these measurements are possible if the
waveform is slightly imperfect. If noise detracts from
measurement accuracy with the slit width set at 1/8 the PWHM,
a slightly larger slit width may be appropriate. Shimadzu
spectrophotometers normally achieve satisfactory resolution
and light intensity for concentration measurements on
solutions when the slit width is set between 1 nm and 2 nm.
The slit width is normally set to 5 nm or above for
measurements of solids using the integrating sphere. A larger
slit width is set to reduce noise due to light losses in the
integrating sphere, as high resolution is often not required
when measuring solids.
Concave diffraction grating
Fig.12 Concave Grating Monochromator
Light intensity
Peak
PWHM
539.5
540.0
540.5
Wavelength (nm)
Fig.13 1 nm-Bandwidth Light
5
Monochromators
4. Conclusions
1) Shimadzu Absorption Spectrometry Course Text, "Principle, Construction,
and Applications of Spectrophotometers" (Shimadzu Corporation)
1.000
: 1 nm resolution
: 2 nm resolution
0.800
: 5 nm resolution
0.600
Abs.
We explained the monochromator, which extracts
monochromatic light from polychromatic light.
However, when monochromatic light enters the monochromator,
it exits only in a direction specific to the diffraction grating.
This property can be used to determine the wavelength of the
monochromatic light. This is the method normally used when
the monochromator is used alone. A monochromator is
incorporated into fluorescence spectrophotometers and
emission spectrometers to determine the wavelength of
fluorescence lines or emission lines emitted from the sample.
In this case, the monochromator is located between the
sample compartment and detector.
The detector will be described in the next UV TALK LETTER.
We hope you will continue to enjoy reading the UV TALK
LETTERS.
0.400
0.200
0.000
230.00
240.00
250.00
260.00
nm
270.00
280.00
Fig.14 Difference in Spectrum Shapes Due to Resolution
(Analysis of Ethanol Solution of Benzene)
Spectroscopy Business Unit, Analytical & Measuring Instruments Division
Toshio Kimura
6
Application
UV Talk Le t t e r Novem be r 2 0 0 9
Color Measurement
Color measurement
1. Color
2. Color Measurement
When a person views an object, light from a light source that is
reflected from the object (or passes through the object) enters
the eye and is collected by several types of photoreceptor
cells in the retina. The proportion of light collected by these
cells is sent to the brain and sensed as color. In practice, the
simple proportion of light collected undergoes various
processing as it passes along the nerves before being
recognized by the person as color.
Color measurements are a method of expressing the colors
sensed by humans as values.
Color measurements are related to illumination, spectral
characteristics of the object, and the spectral sensitivity
characteristics of the human eye. As the spectral distribution
of the illumination and the spectral sensitivity characteristics
(color-matching function) of the eye are defined in the JIS
standards, a color value can be calculated if the spectral
reflection of the object is known. (If the light passes through
the object, the spectral transmittance can be used for the
calculation. However, the spectral reflectance is used in the
explanations below.) To explain in more detail, in the JIS
standard, the spectral distribution of the illumination and colormatching function are calculated using multiple conditions. We
are familiar with a change in color when the illumination is
changed. Therefore, a different coefficient is set for each
illumination spectral distribution. In addition, the color also
changes according to the viewfield (viewing angle), due to the
relationship with the sensitivity distribution characteristics of
the retina. Consequently, the JIS standard sets different colormatching functions according to the viewfield.
Color measurements require a wavelength range from 380 nm
to 780 nm, which is equivalent to the wavelengths that can be
sensed by the human eye. Color measurements can be made
by calculations based on spectral reflectance measurements
by a UV-VIS spectrophotometer across this wavelength range.
Color measurement software is available for simple color
measurements.
To perform color measurements with a UV-VIS
spectrophotometer, first measure the spectral reflectance of
the object. Calculations based on the spectral distribution of
the illumination, the spectral reflectance obtained for the
object, and the color-matching function express the color as a
numeric value. Illumination spectral distributions and colormatching function values are stored in the color measurement
software to obtain color measurement values when the spectral
reflectance spectrum is measured.
The XYZ tristimulus values are the basis of color measurement.
JIS Z 8722 "Methods of color measurement -- Reflecting and
transmitting objects" calculates the XYZ tristimulus values
using the expressions below.
...................................... (1)
Where,
S(λ): illumination spectral distribution value at wavelength λ
x(λ), y(λ),z(λ): color-matching function values in the XYZ color system
R(λ): sample spectral reflectance
Δ λ: wavelength interval for calculation
In addition to the XYZ tristimulus values, several other color
specification systems for expressing colors are known. The
color measurement software can perform calculations in the
following color specification systems: XYZ tristimulus values,
xy color coordinates, Hunter Lab color scale, L*a*b* color
system, L*u*v* color system, and U*V*W* color system. Values
for color specification systems other than the XYZ tristimulus
value system are calculated from the XYZ tristimulus values.
3. Color Difference
Brain
Eye
Spectral
distribution
Color-matching function
Object
Reflectance
Fig.1 What is Color Measurement?
A color specification system is a method of expressing colors
as numerical values, while color difference expresses the
difference between colors. Calculations to numerically express
color difference values use the Uniform Color Space (UCS)
color specification system that is closer to the human visual
sense. The L*a*b* color system is a typical UCS color
specification system. L* represents the brightness, and a* and
b* represent the hue and saturation. JIS Z 8729 "Colour
specification -- CIELAB and CIELUV color spaces" shows the
method of calculation in the L*a*b* color system.
The color difference is calculated using the L*a*b* value for
each object (sample) color. The color difference Δ E*ab in the
L*a*b* color system is determined using expression (2) in JIS Z
8730 "Color specification -- Color differences of object colors."
...................................... (2)
7
Application
Color Measurement
If the color coordinates of two objects (samples) are denoted
L* 1 a* 1 b* 1 and L* 2 a* 2 b* 2 , it can be seen from the expressions
The color measurement software can simultaneously display
up to six calculation items. If the calculation items are
changed while reading the spectrum, the displayed color
measurement values change immediately.
Fig. 3 shows the screen to select the calculation items.
that the color difference is equivalent to the distance between
two points in the L*a*b* color space. The greater the
difference between the two colors, the larger the color
difference value.
In addition to displaying the color system and the color
difference in the color specification system, the color
measurement software can perform other calculations
including whiteness index, yellowness, major wavelengths, and
excitation purity.
4. Setting Color Measurement Conditions
Several conditions are set for the color measurement
calculations. These conditions are the illumination (light
source) and viewfield (viewing angle).
Settings for the illumination are required, as the color varies
according to the illumination on the sample. Illumination
settings include A, B, C, and D65. In the JIS standards, these
are called standard illuminant and supplementary standard
illuminant. The spectral distribution is different for each
illumination. For example, standard illuminant A is used to
calculate object colors under illumination by an incandescent
light bulb. Standard illuminant D65 is used to calculate object
colors in daylight including the UV light region. The color
measurement software allows user-defined illumination
settings to handle illumination conditions not provided as
standard.
The viewfield (viewing angle) must also be set, as the color
appears different when a sample is observed close-up or from
a distance. For a viewfield up to 4 degrees, a 2° mean viewing
angle is used for the calculations (color viewed from a
distance); for a viewfield over 4 degrees, a 10° mean viewing
angle is used for the calculations (color viewed close-up). The
color-matching functions differ for a 2° mean viewing angle
and a 10° mean viewing angle.
If the parameter settings are changed while reading the
spectrum, the displayed color measurement values in the list
change immediately.
Fig. 2 shows the calculation parameter setting screen.
Fig.2 Calculation Parameter Settings
8
Fig.3 Selecting the Calculation Items
5. Spectral Reflectance Measurements
The measurement parameters must be set before measuring
the spectral reflectance.
To set the measurement parameters, set the photometric value
(transmittance / reflectance), wavelength range (normally set
from 380 nm to 780 nm), scan rate, slit width, and sampling pitch.
Fig. 4 shows the measurement parameter setting screen.
Fig.4 Measurement Parameter Settings
An integrating sphere is often used to measure the spectral
reflectance of an object. Fig. 5 shows the photograph of an
integrating sphere with a sample in position. The spectral
reflectance can be measured by installing the sample as
shown in the photograph.
Fig. 6 and Fig. 7 show examples of spectral reflectance
measurements using an integrating sphere. Fig. 6 shows the
spectral reflectance measurement results for pink paper, and
Fig. 7 shows the spectral reflectance measurement results for
light-blue paper. Barium sulfate was used as the standard
white plate for reference.
The visible range encompasses the blue color system (400 nm
to 500 nm), green color system (500 nm to 600 nm), and red
color system (600 nm to 700 nm). The graphs show that the
pink paper reflects more in the red color system, while the
light-blue paper reflects more in the blue color system.
UV Talk Le t t e r Novem be r 2 0 0 9
Integrating sphere
The color measurement software can also display the color
difference. The color difference is calculated based on a
reference sample (the sample with ID set to 0 [green frame in
diagram]). In this case, the pink paper is set as the reference
sample. The color difference between the pink paper and the
light-blue paper is ΔE*ab = 25.41 [black frame in diagram].
Measured sample
Fig.5 Sample Positioned on Integrating Sphere
Fig. 8 Display of Color Measurement Results
Fig. 6 Measured Reflectance Spectrum for Pink Paper
A chart display function shows the color measurement results
in a clearly visible form. The color measurement results shown
in the list display can be displayed as a chart. Fig. 9 shows the
chart display of the color measurement results in Fig. 8.
In the L* graph at the left, the color becomes brighter as the
data point moves upward, and the color becomes darker as
the data point moves downward. In the a*b* graph at the right,
the color becomes duller as the data point moves toward the
center, and the color becomes more brilliant as the data point
moves toward the perimeter.
In addition, the radius vector angle from the center represents
the hue. For example, the top-right direction from the center of
the circle represents red colors.
Light-blue paper
Pink paper
Pink paper
Light-blue paper
Fig. 7 Measured Reflectance Spectrum for Light-Blue Paper
The color measurement values calculated from the spectral
reflectance are displayed as a list. Naturally, calculations can also
be performed on existing spectral reflectance data.
Fig. 8 shows a display of the color measurement results. The
calculation conditions were illumination C and 2-degree viewfield.
The first row shows the color measurement results for the pink
paper (L*=79.45, a*=11.50, b*=4.48 [red frame in diagram]). The
second row shows the color measurement results for the light-blue
paper (L*= 81.71, a*=-11.56, b*=-5.95 [blue frame in diagram]).
Fig. 9 Chart Display
9
Application
Color Measurement
6. Data Correction
A standard white plate is used for the spectral reflectance
measurements required to measure the object reflection color
(color measurement by reflection). The standard white plates
used include barium sulfate, magnesium oxide, alumina, and
fluororesin. However, as these have high reflectance across
the overall measurement wavelength range, adequate color
comparison is possible if the same instrument is used.
However, as a standard reflectance plate does not form a
perfect diffusing surface and does not offer 100% reflectance,
the spectral reflectance values measured for samples are
relative values. Extremely high-accuracy measurements are
required to make a comparison of the measured results
obtained by different instruments. Making highly accurate
measurements requires correction of the spectral reflectance
to the spectral ratio reflectance with respect to a perfect
reflection diffusing surface. The white plate correction function
is used for this correction. By entering the spectral reflectance
for the corrected standard white plate, the measured spectral
reflectance is corrected to be equivalent to the measured
results for a perfect reflection diffusing surface.
Conversely, correction for the thickness is applied to
measurements of the transmission color of an object (color
measurement by transmission). A change in sample thickness
results in a change in spectral transmittance that results in
different color measurement results. Thickness correction is a
function to determine the transmission color for the required
thickness (target thickness).
Thickness correction by entering the actual measured
thickness, the target thickness for which the color is to be
determined, and the surface reflectance (or surface
reflectance calculated from the refractive index) permits
comparison of transmission colors between samples of
different thickness.
Thickness correction makes the following calculations. (See
Fig. 10.)
1) Determine the internal transmittance, excluding the
measured surface reflectance of the sample.
2) Apply thickness correction to the internal transmittance and
subsequently add the surface reflectance.
r
r
r
wavelength.
...................................... (3)
Where,
T 1 : measured transmittance (%)
T 1 ': internal transmittance (%) with respect to measured
transmittance (%)
r: sample surface reflectance
t 1 : measured sample thickness [measured thickness] (mm)
t 0 : sample thickness to determine the transmittance for
[target thickness] (mm)
T 0 : calculated transmittance (%)
Instead of entering the surface reflectance, the value
calculated from the refractive index n using following
expression can be entered:
This yields 4% surface reflectance for glass with refractive
index 1.5.
Color calculations are performed after determining thicknesscorrected transmittance values at each wavelength.
7. Summary
JIS standards define calculation methods and coefficients for
color measurements in detail. If the spectral reflectance is
known, the calculations can be performed using spreadsheet
software. However, different coefficients are required for
different illumination and viewfields, which requires a huge
number of inputs.
The color measurement software can be used to select the
conditions and measure the spectral reflectance to simplify
color measurements.
Tokyo Applications Development Center,
Analytical Applications Department,
Analytical & Measuring Instruments Division
Hirokazu Abo
r
T1
T0
t1
t0
Measured
Corrected
Fig. 10 Concept of Thickness Correction
10
Expression (3) is used for actual thickness correction
calculations to determine the transmittance T 0 at each
Q&A
Liquid Sample Spectrum Measurement
Q
A
UV Talk Le t t e r Novem be r 2 0 0 9
How should I measure the spectrum
for a solution?
Two types of spectrophotometer construction are available. One is the single-beam type
with a single light beam in the sample compartment. The other is the double-beam type
that has two light beams in the sample compartment. (See UV TALK LETTER Vol. 1 Q&A.)
The measurement procedure using each type is explained below.
Single-beam type
1. Put the solution in a cell and put the cell in the cell holder.
2. Conduct baseline correction.
3. Remove the cell and discard the solution. Rinse the cell twice with the measured
sample solution to be measured. Fill the cell with sample solution and mount it in the
cell holder.
4. Conduct the measurement. Repeat steps 3 and 4 for the number of samples.
Double-beam type
1. Put the solution into two cells. Mount the cells in the reference (R) and sample (S) cell
holders.
2. Conduct baseline correction.
3. Remove the sample (S) cell and discard the solution. Rinse the cell twice with the
measured sample solution to be measured. Fill the cell with sample solution and mount
it in the cell holder.
Leave the cell at the reference (R) side unchanged.
4. Conduct the measurement. Repeat steps 3 and 4 for the number of samples.
11
NEW PRODUCTS
BioSpec-nano
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Easy-to-use system offers quick and easy nucleic acid quantitation.
This is a dedicated spectrophotometer for checking the concentration and purity of nucleic acid samples.
It analyzes 1 to 2 μL trace samples of nucleic acids. Simply drop the sample onto the window with a
pipette and press the [Start] button on the instrument or click the [Start] button on the software screen to
start automatic light path setting, measurement, and sample wiping after measurement. It is not necessary
to make vertical arm adjustments or wipe the widow with a cloth.
Dedicated software simplifies operation. Just click buttons on the toolbar to conduct basic operations
including measurement, report printing, and exporting data.
Founded in 1875, Shimadzu Corporation, a leader in the
development of advanced technologies, has a distinguished
history of innovation built on the foundation of contributing to
society through science and technology. We maintain a global
network of sales, service, technical support and applications
centers on six continents, and have established long-term
relationships with a host of highly trained distributors located
in over 100 countries. For information about Shimadzu, and to
contact your local office, please visit our Web site at
JQA-0376
www.shimadzu.com
SHIMADZU CORPORATION. International Marketing Division
3. Kanda-Nishikicho 1-chome, Chiyoda-ku, Tokyo 101-8448, Japan
Phone: 81(3)3219-5641 Fax. 81(3)3219-5710
URL http://www.shimadzu.com
Printed in Japan 3295-10911-15A-NS
The contents of this brochure are subject to change without notice.
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