FIELD: measurement of current speed of fluid medium. SUBSTANCE: ultrasonic facility includes couple of ultrasonic converters installed along current of fluid medium, transmitting unit, change-over unit, receiving unit, unit measuring time interval, signal synchronization unit and controller. Transmitting unit generates ultrasonic signal with frequency modulated by pseudonoise code of spectrum expansion band. Receiving unit demodulates output signal of change-over unit and determines moment when its own signal is identical to signal of transmitting unit. In correspondence with another version transmitting unit selects one pseudonoise code from aggregate of signal sequences. EFFECT: increased accuracy of determination of time of transit of ultrasound and measurement precision of current speed over crooked path. 6 cl, 12 dwg
