25
Transmittance measurements
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Before starting transmittance calibration and
measurements, attach the LAV (ø25.4 mm) target
mask and position the white calibration plate at the
reflectance measuring port.
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Before starting transmittance calibration and
measurements, set the measurement area to LAV
and the specular component to SCI using the
software.
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Before starting transmittance calibration and
measurements, set the UV light quantity using the
software.
1.
Open the cover of the transmittance chamber.
2.
Place the specimen against the illumination
window tightly. (When measuring a liquid
specimen, the specimen container must be
placed against the illumination window.)
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The specimen must be placed so that the area
to be measured entirely covers the entire
illumination window.
Memo
• Although the specimen can be plaied in front of either the illumination or receiving window, it is reccommended
that it is placed in front of the illumination window. In this position, the illumination/observation geometry is
diffuse illumination/0° vowing angle. In the position in front of the receiving window, the illumination/observation
geometry is approximately 0° :0° . It does not strictly satisfy the difinition of sush as CIE No.15. However, this
presents no problem if the values are used as relative values.
• It is recommended that the optional Transmittance Specimen Holder CM-A96 be used to hold the specimen in place.
• In the case of a liquid specimen, use of an optional cell (CM-A97 to 99, A130 to 132) is recommended.
c
If you are going to use a container other than the above cells, it must be transparent and constructed in such
a way that it can be positioned with opposing surfaces parallel to both illumination and receiving windows.
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Take care not to spill the liquid specimen on the CM-3700A. Should there be any spillage, immediately
wipe it with a soft, dry cloth.
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Never measure flammable liquids.
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No measurements must be performed if the specimen or its container is scratched or dirty. If you hold the
measuring surface of the specimen with your fingers, it will be marked with fingerprints, so always hold
another part of the specimen when setting it in place.
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Air bubbles on the inner surface of the specimen’s container will hinder correct measurements, so make
sure that all air bubbles are removed before measurement. (Air bubbles sometimes develop even if the
container is just left standing still.)
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Correct measurements will be hindered if water drops
develop on the specimen or its container due to
condensation.
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Liquids containing particles may cause unstable
measurements due to precipitation of the particles.
3.
Close the cover of the transmittance chamber.
Receiving
window
Illumination
window
