FIELD: municipal and industrial water-supply systems. SUBSTANCE: flow is removed from zone of its partial blocking by full pressure line and directed to zone of flow longitudinal section by means of measuring tube positioned in body. Zone of flow longitudinal section is set by static pressure line. At beginning of next measurement cycle the first monitoring pulse is radiated, and at moment of its second recording the second monitoring pulse is radiated. During the second recording of the second monitoring pulse formation of two sequences of information signals is started, and time interval between information signals preset by ordinal number is filled with counterpulses. Number of counterpulses formed within time of performance of next measurement cycle is read, and instantaneous flow rate is judged by result of reading. Counter pulses formed during next measurement cycle are summed up with count pulses formed when performing previous measurement cycles, and total flow rate is determined by summing-up result. EFFECT: enhanced accuracy of flow-rate determination. 2 cl, 3 dwg 2 CL, 3
