METHOD OF TRIGGERING ULTRASONIC FLOW METER* AND ULTRASONIC FLOW METER ADAPTED TO SAID METHOD

摘要

A method for triggering an ultrasonic flow meter comprising a synchronized ring circuit, consists of periodically turning the ring circuit on and off by trigger pulses whose repetition period is varied within the range of possible changes of the repetition period of autocirculation pulses of the synchronized ring circuit until an autocirculation pulse is matched with a trigger pulse. At such point, the application of trigger pulses to the synchronized ring circuit is discontinued by matching the frequency of the trigger pulses with that of the autocirculation pulses via continuous automatic phase control of the trigger pulse frequency. With no autocirculation pulses in the synchronized ring circuit, the application of trigger pulses is resumed.