Doppler Flowmeters Manufacturers

The Doppler flowmeter measures the velocity of particles moving with the flowing fluid. It requires no zeroing and measurements are virtually unaffected by the vessel wall. The acoustic signals of known frequency are transmitted, reflected from particles, and are picked up by a receiver. The received signals are analyzed for frequency shifts and the resulting mean value of the frequency shifts can be directly related to the mean velocity of the particles moving with the fluid. One transducer produces 2 pulsed doppler ultrasonic beams. The first is a widde beam that insonates the whole vessel area. The second is a narrow reference beam placed entirely within the bloodstream of the same cross section to compensate for tissue attenuation.