FIELD: measuring equipment in devices for determining the quadrature-phase shift of harmonic signals with discrimination of phase lead or lag, mainly used at infra-low frequencies, when signal amplitudes may considerably differ and vary within a wide band. SUBSTANCE: in the device, using division unit 3, whose first (1) and second (2) inputs serve as the device inputs, differentiation unit 4 cut in between the output of unit 3 and information input of display unit 8, series-connected limiter unit 5, averaging unit 6, comparator 7 and cut in between the output of unit 3 and control input of unit 8, when the averaged values of frequency discrimination signal equal zero, the sign of the output pulse of display unit 8 is determined, which determines the sign of quadrature-phase shift of the harmonic signals under examination. EFFECT: enhanced accuracy. 2 dwg
