Ultrasonic flow meter calibration system and method

Abstract

An ultrasonic flow meter configured to measure a flow within a conduit configured for autozeroing during active flow operation of the flow meter. The flow meter includes a printed circuit board including circuitry for conducting ultrasonic transit time flow measurements, the printed circuit board including transducer swap relays and first and second transducer cables connecting the first and second transducers, respectively, to the transducer swap relays. The flow meter further includes a programmable processor configured to generate flow measurement data based on an ultrasonic flow meter calibration performed by the ultrasonic flow meter in situ while measuring flow through the conduit. Calibration includes determining a zero offset value, determining a swap offset value by measuring transit time forward and backward between the first and second transducers through the flow in the conduit, activating the transducer swap relays to physically swap the first and second transducers, and measuring transit time forward and backward between the swapped first and second transducers through the flow in the conduit, determining a flow zero value based on the zero offset and swap offset, and generating flow rate data based on the flow in the conduit and the flow zero offset.