DESIGN OF A NEW PULSED-FIELD ELECTROMAGNETIC FLOWMETER

Electromagnetic blood flowmeters have suffered from avariability of the recording baseline, caused by transformer-induced signals in the electrodes and wiring of the probe. This paper describes an instrument that overcomes these problems by using a transformer voltage nulling method in the probe and a field waveform that gives rejection of the transformer voltage. The transformer voltage can be adjusted without interrupting the flow. The use of these techniques has allowed the design to be simplified, thereby reducing the cost.