FIELD: medical engineering. SUBSTANCE: device has photometric cavity provided with inlet aperture and main and auxiliary outlet apertures. The main outlet aperture enabling one to calibrate the cavity has movable cover with two surfaces one of which has diffuse reflection coefficient 100% and the other one - 0%. Photoelectric transducer connected to recording unit is mounted in the auxiliary outlet aperture. The recording unit is usable for measuring biological tissue absorption coefficient for incident laser radiation. The recording unit has amplifier the output of which is connected to the first input of differential amplifier the second input of which is connected to movable point of potentiometer connected to constant voltage source circuit. Differential amplifier output is connected to movable point of potentiometer in its feedback circuit and to analog measuring instrument. EFFECT: high accuracy of measurements. 1 dwg
