Reflectivity meter for measuring the spectral radiance factor for 45/0 measuring geometry

摘要

In order to avoid measurement error when measuring the spectral radiance factor of body surfaces having ''45/0 measurement geometry'' using XENON flash lamps or XENON short-arc lamps of low power as illumination as a consequence of the geometrical influence of the various spatial discharge sections in the case of successive flashes, or to avoid arc instability in XENON short-arc lamps of low input power (< 150 W), a beam splitter is to be inserted between the light source and specimen in such a way that, seen from the light source, the reference specimen is arranged at the location of the mirror image of the beam splitter. The ratio of the radiation components which impinge on the measurement specimen to those which reach the reference specimen is constant and does not depend on the disturbing geometrical influences.