Ultrasonic flowmeters measuring water depth and current speed e.g. for river

摘要

Ultrasonic flowmeters in pair are based on a catamaran-form floating platform (7,7'). This has a central deck (8) carrying a sender/receiver (15), ultrasound vibrators (10,11) for determination of water depth and ultrasound speed, and pairs of vibrators (12,12',13,13',14,14') for determination of current speed. The unit is moved by remote control to determine current in different places. It is linked to the fixed unit, usually land-based, by high-frequency cables (17) through which measurement results can be exchanged. The fixed unit measures ultrasound pulses over an extended time by comparing depth, ultrasound speed, part-current and entire-current quantities. It also ensures that ultrasound pulses are transmitted at the optimal angle of incidence and are fully reflected from the river or sea-bed, irrespective of the floor composition.