TWO-BEAM PHOTOMETER Russian patent published in 1996 - IPC

FIELD: measurement technology. SUBSTANCE: invention belongs to measurement technique of photometric parameters and can be used to measure light transmission and scattering factors of air atmosphere. Salient feature of invention lies in regulation of intensity of both light sources in inverse proportion to conversion factor of first current converter where photodiode is used which ensures possibility of measurement of unmodulated light fluxes, for instance of brightness of surrounding background. Apart from this change of transmission factor of second photoconverter does not lead to additional error as it operates as null indicator, error from change of spectral composition of radiation is practically excluded and error of conversion of unmodulated light fluxes appears to be minimal. This is achieved by availability of controlling input in both light sources, by coupling of output of each comparison circuit to controlling input of proper light source and by coupling of both inputs of second comparison circuit to output of second photoconverter. EFFECT: enhanced authenticity of measurements. 1 dwg