PerkinElmer Frontier Optica FT-IR, Руководство пользователя

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Measuring Optical Components . 57
Summary
In this chapter, we have described a number of parameters that affect the accuracy of your
optical measurements when measuring transmittance.
It is important to ensure that the resolution is good enough to measure the features of
interest, with the limitation that using higher resolution will increase the noise or the
measurement time.
To achieve high ordinate accuracy at non-zero %T values the J-stop and B-stop image sizes
should be set to 6.00 mm or lower. However, when measuring regions that are close to
0%T, for example to determine blocking efficiency, it may be advisable to use the maximum
J-stop and B-stop image sizes to reduce noise.
Reflection measurements
Reflection measurements can be made using the appropriate accessories. They do not
require the reduced J-stop and B-stop image sizes that are needed to minimize beam
distortions caused by transmission samples.