FIELD: mechanical engineering. SUBSTANCE: proposed method employs device for periodic measurement of flow velocity in preset area of pipe line cross section which includes measuring line connected to total and static pressure lines by means of two connecting hoses through two gate valves and electronic unit. Three ultrasonic transducers are mounted along measuring line at base distance from each other. At the beginning of first and subsequent cycles of measurements conducted at equal time intervals, first and third transducers form first and second sounding impulses (acoustic signals) which are recorded by second transducer. Number of records of second sounding impulse transducer during one cycle of measurements is indicative of instantaneous flow rate. Electronic unit includes standard pulse generator, two sounding impulse generators, seven electronic switches, two time delay lines, three diodes and recording and indicating circuit. EFFECT: increased resolving power. 3 cl, 3 dwg
