FIELD: geophysical and meteorological instrumentation. SUBSTANCE: device is made of optical focusing system with separable filter absolutely opaque for lateral component of solar flux of electromagnetic radiation, optical concentrator presenting regular polyhedron and mounted after optical filter on principal optical axis of focusing system so that its convex polyhedral angle faces radiation detector. Symmetry axis of polyhedral angle coincides with principal optical axis of focusing system. Device also has radiation detector placed at angle of 30-60 degrees with respect to principal optical axis of focusing system after concentrator, signal processing unit incorporating amplifier of radiation detector and indicator averaging and counting measured parameter. EFFECT: formation of objective reference channel in measurement circuit thanks to exclusion of effects of solar activities on measurements, simplified calibration of measurement circuit. 1 dwg
