Binder APT.line KBF-LQC Series, Руководство по эксплуатации

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KBF-LQC (E5.2) 12/2010 page 76/106
16.4 Spatial sensitivity
Spherical sensors are used for UVA and the visible spectral range.
So the spatial sensitivity of the detectors is adapted to the spatial effect of radiation regarding the photo-
chemical effect to be weighted in the charging material. Due to the spatial extension of the sample the
really impinging radiation dose can be determined much more realistic than using planar (cosine
adapted) sensors.
Characteristic features of spherical sensors
Compared to planar (cosine adapted) sensors, spherical sensors measure to a great extent directionally
independent. They are suitable for all kinds of samples with spatial extension or spatially distributed ob-
jects (e.g. bottles and other vessels, pills, dissolved substances). Here, the radiation intensity or illumina-
tion really entering the sample can be realistically determined with spherically measuring light sensors.
The energy entering the sample in the visible, and UV range is thus weighted in optimal approximation to
its real photochemical effects.
Use of planar sensors with spatial objects leads to underrating of the radiation energy leading to exces-
sive exposure duration and possible wrong positive photochemical effects. In ICH guideline Q1B ac-
tinometric systems in glass ampoules are proposed as a reference for exposition to radiation; the photo-
chemical effect to a defined test solution caused by radiation exposure is photometrically determined.
Using a solution in an ampoule the photochemical effect is determined directionally independent. Use of
spherical sensors in the BINDER measurement system imitates this quantification of the photochemically
effective radiation in optimal approximation and permits an exposition exactly responding to the demands
of ICH guideline Q1B.
Figure 29: Spherical BINDER sensors for VIS, and UVA measurement
Spherical sensor
Error
Divergence [%]
Angle of incidence [degrees]
-40%
-35%
-30%
-25%
-20%
-15%
-10%
-5%
0%
0 20 40 60 80 100 120 140 160 180