FIELD: examination of hydrophysical fields in the course of execution of ecological investigation, experimental hydrodynamics, oceanology and some other fields of technology where monitoring of turbulent medium is required. SUBSTANCE: device incorporates first, second, third and fourth velocity-to-electric signal converters placed along one straight line, band-pass filter, squarer, averaging unit and threshold unit connected in series. Second input of threshold unit is connected to source of threshold signal and its output is output of device. Device also has unit computing function. Second, third and fourth velocity-to-electric signal converters are positioned on one side of first velocity-to-electric signal converter. Distances between first and second, first and third, first and fourth velocity-to-electric signal converters meet conditions R14>R13>R12. First to fourth inputs of unit computing function are connected to first to fourth outputs of velocity-to-electric signals converters correspondingly. Output of above- mentioned unit computing function is connected to input of band-pass filter. EFFECT: increased sensitivity of device. 1 cl, 3 dwg
