93. A Novel Ultrasonic Transducer Module with an Own Reference Sound Channel for Flow Measurement

Zero error caused by transducer system asymmetry which drifts with the environment change is a severe limitation to the performance improvement of an ultrasonic flow meter. This chapter proposes a novel ultrasonic transducer module with an own reference sound channel for zero error calibration. Different from traditional transducers, the module consists of two energy conversion terminals which are connected by a reference sound channel. Part of the ultrasound generated by one terminal transfers into the flow media and finally into another terminal, which is used for flow measurements. The rest propagates through their own sound channel as reference signal for zero drift acquisition. According to the difference of the measuring signal and the reference signal, the zero drift error can be calibrated. We have illustrated the construction, zero elimination method, and design theory of the module with simulation employed for validation. A prototype has been developed and the preliminary results demonstrate an observable decrease of the zero drift error.