Time difference ultrasonic wave flowmeter is widely applied in industry and daily life

and the flow measurement precision is largely determined by the detection precision of time difference between upstream and downstream. Since"zero error"and"temperature drift"exist in practice

it’s very important to eliminate influence.They can be restrained by improvement in the reciprocity of measurement system circuit

according to the electroacoustic reciprocity theorem. Symmetry of transmitting circuit and receiving circuit impedance and reciprocity of measurement system exist strong connection. By matching excitation circuit impedance and receiving circuit impedance can improve reciprocity of measurement system

and present measurement system is improved

and laboratory platform is built to carry out actual measurements. Experiments show that this circuit design can effectively restrain"zero error"and"temperature drift".