engleski

Optical filters for reflectance measurement

Reflection measurements can often be extremely complex, especially in the case of powder samples. Powder sample reflectance implies the use of some form of optical filter (glass, PVC, ..) which is placed directly on the sample. Given the type of measurements being performed (reflectance in the UV, visible or IR range), it is important to use a complementary filter that transmits electromagnetic radiation in the part of interest in order to obtain adequate results. Each filter has some level of response in different regions of the spectrum that ultimately must be taken into account when measuring the reflectance of the selected powder samples in order to minimize the impact of the experimental setup on the measurement results. The study examined the properties of three filters with different optical characteristics using three different sources of electromagnetic radiation (deuterium lamp, tungsten lamp and xenon lamp). Also, two geometries of measurement 45 ° / 0 ° and d / 8 ° were used. The obtained results will enable a more appropriate selection of a complementary pair, light source-measurement geometry, for individual optical filters.

optical filters ; reflectance ; measurement geometry

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