FIELD: polarization differential refractometry. SUBSTANCE: gear measuring difference of refractive indices has source of radiation polarized linearly, optical prism unit with three prisms 2,3,4 and gaps 5,6 between center 3 and extreme prisms which are used as vessels for examined liquids and analyzer-register. Normals of contacting faces of center prism are not located in one plane. Gaps 5,6 between prisms 2,3 and 3,4 are filled with examined liquids. One of them has known refractive factor. Examined substances are placed in sequence. Polarization plane of initial radiation on to input face of prism 2 is located at angle α, predominantly 45 deg, with respect to first incidence plane. Incidence planes of beam on to substances are mutually perpendicular. Light passing prism unit hits polarization analyzer-register fixing change of azimuth of light polarization enabling difference of refractive indices of substances to be determined. EFFECT: simplified design of circuitry of gear, increased measurement accuracy. 2 cl, 3 dwg
