Method of determining liquid flow in a conduit

摘要

The instant invention provides a method for determining the streaming velocity of a streaming liquid by injecting a thermopulse into the liquid and measuring its transit time. The pulse is detected by its ascending flank at downstream points and by its ascending or descending flank at its point of injection. For short transit times, provision is made to eliminate the heat up time of the heating wire imparting the pulse from the transit time measurement. The liquid may stream continuously or discontinuously, and if the later, provision is made to delay measurement on initiation of flow until the flow pattern has stabilized. The time is determined by counting pulses from a pulse generator during the period the pulse is traveling between the point of injection and a detection point or between two detection points.