System for measuring infrared radiant flux with application of new methods of noise detection and reduction

Maciej Bodnicki , Piotr Sakowicz

Abstract

Open optoelectronic connections are used in many modern meters. In numerous applications, a measuring system is to detect changes in optical coupling between elements of the connection. These changes may be triggered by a moving diaphragm, or a changing optical permeability of a factor separating an illuminator from a photodetector. The article presents the original solution based on the subtraction from the photodetector’s measurement signal cyclically stored its noise signal obtained during breaks in the emitter’s work. The developed solutions ensure the possibility of detecting signals comparable to the photoelement noise level – the application in the differential system of one photodetector, illuminated in an intermitted manner, as a source of a measuring signal, as well as noise signal, in practice allows to reduce thermal noises of the photodetector. The system ensures high linearity of conversion.