FIELD: measurement technology. SUBSTANCE: two beams with known relation of average powers (energies) are formed from input laser radiation. One beam is directed onto standard (reference) measurement means, and three other one is directed onto tested measurement means. Basic error of tested measurement means is determined by comparing simultaneous readings of both means accounting with average powers (energies) relation. Device for realization of the method has laser irradiator, aligned in series with gate, polarization divider, which has linear polarizer and two-beam polarizing element. Moreover, linear polarizer is made for rotation about axis of laser irradiator. EFFECT: improved precision of measurement. 2 cl, 2 dwg
