Fluorescent Measurement; When Fluorescent Calibration Is Performed; Calculating Fluorescent Reflectance; When Fluorescent Calibration Is Not Performed - Konica Minolta CM-3600A Instruction Manual

Fluorescent Measurement

The CM-3600A incorporates two types of xenon lamps as light sources for fluorescent measurements
(UV full light source and UV cut light source) and performs numeric calculation of the reflectance
when the specimen is illuminated by these two light sources to obtain fluorescent reflectance.
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WHEN FLUORESCENT CALIBRATION IS PERFORMED:

When SpectraMagic™NX is used, the following four fluorescent calibration methods
are available to enable accurate measurement of fluorescent reflectance.
1. Profite mode
Correction coefficients for fluorescent measurement are obtained based on the calibrated reflectance profile of
the fluorescent standard plate (the reflectance profile is created by entering reflectance for each wavelength).
2. Tint mode
Correction coefficients for fluorescent measurement are obtained so that the measured
CIE Tint value for the fluorescent standard plate is within the specified range (Tint value
for the fluorescent standard plate calibrated with a D65 light source is entered) .
3. Whiteness (WI) mode
Correction coefficients for fluorescent measurement are obtained so that the measured CIE
WI (whiteness index) value for the fluorescent standard plate is within the specified range (WI
value for the fluorescent standard plate calibrated with a D65 light source is entered).
4. Tint and WI mode
Correction coefficients for fluorescent measurement are obtained so that the measured CIE Tint
and WI values for the fluorescent standard plate are both within the specified range (Tint and
WI values for the fluorescent standard plate calibrated with a D65 light source are entered).
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CALCULATING FLUORESCENT REFLECTANCE

Based on the measured reflectances for the fluorescent standard plate obtained under the UV full light
source and under the UV cut light source, the amount of fluorescence is obtained. The correction coefficients
for fluorescent measurement are then determined so that the given reference values are satisfied.
(Calibration example: Profile mode)
These correction coefficients are then used to obtain the fluorescent reflectance by performing numeric
calculations using the measured reflectances under the UV full light source and under the UV cut light source.
(The reflectances at cut wavelengths under UV cut light source are set to 0%.)
As a result, the CM-3600A can keep the fluorescent output quantity as close
to the standard as possible, without the need for adjusting the quantity of
ultraviolet light, which is required in the case of conventional models.
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WHEN FLUORESCENT CALIBRATION IS NOT PERFORMED

The UV full xenon lamp of the CM-3600A has a spectral distribution similar to that of the D65
light source. Therefore, when high-accuracy fluorescent measurements are not required,
normal measurement of reflectance can be used to measure fluorescent reflectance.
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UV CUT LIGHT SOURCES

With the CM-3600A, UV400 cut light source (with radiation at wavelengths of 390 nm or lower eliminated)
and UV420 cut light source (with radiation at wavelengths of 410 nm or lower eliminated) are provided.
Under UV
Under UV full light
full light source
source
Under D65 light source
Under
(entered reference value)
D65 light
source
Under UV cut light
source
33
b a
Under UV cut light source
Correction coefficient=b/a