METHOD FOR TRIGGERING ULTRASONIC FLOW METER AND ULTRASONIC FLOW METER ADAPTED FOR SAME

摘要

ABSTRACTA method for triggering an ultrasonic flow metercomprising a synchronized ring circuit, consists ofperiodically turning the ring circuit on and off by triggerpulses whose repetition period is varied within the range ofpossible changes of the repetition period of autocirculationpulses of the synchronized ring circuit until an auto-circulation pulse is matched with a trigger pulse. At suchpoint, the application of trigger pulses to the synchronizedring circuit is discontinued by matching the frequency of thetrigger pulses with that of the autocirculation pulses viacontinuous automatic phase control of the trigger pulsefrequency. With no autocirculation pulses in the synchronizedring circuit, the application of trigger pulses is resumed.