METHOD AND DEVICE FOR SMOOTHLY ATTENUATING THE LIGHT FLUX WHEN IMITATING BACKGROUND ILLUMINATION WITHOUT THE DISTORTION THE BACKGROUND RADIATION SPECTRUM

摘要

FIELD: optics; instrument engineering.;SUBSTANCE: invention relates to the field of optical instrument making and concerns a method for smoothly attenuating the light flux when imitating background illumination without distorting the background radiation spectrum. Method consists in that a set of diaphragms arranged along a circle on a blackened plate is illuminated by light flux from a source of illumination. Passed through each diaphragm, the light flux falls on the lateral cylindrical surface of the tube and, reflecting from it, illuminates the output end of the tube, where the photosensitive surface of the photodetector is placed. Before the light flux hits the lateral cylindrical surface of the tube, it is weakened, overlapping a part of the area of each diaphragm of the first set of diaphragms with their corresponding diaphragms from the second set of diaphragms arranged on the second blackened plate, installed behind the first light path coaxially with it and rotatable about their common axis. Measurement of the parameters of the photodetector is performed with a weakened light flux, proceeding from the condition that the generated electric current is close to 50 % of the saturation signal of the photodetector.;EFFECT: technical result consists in providing the possibility of smooth adjustment of illumination in a wide range and increasing the accuracy of measurements.;2 cl, 4 dwg