Apparatus and method for determining a flow count

摘要

An apparatus for determining a flow count in an ultrasonic flow meter has an upstream oscillator (22) with an upstream signal (24) having a period proportional to an upstream transit time and a downstream oscillator (26) with a downstream signal (28) having a period proportional to a downstream transit time. The upstream signal (24) is coupled to a positive increment input (30) of a counter (32) and the downstream signal (28) is coupled to a negative increment input (36) the counter (32).