超声波流量计静水时差温度漂移的解决方法

Resolvent for temperature drift of time difference of ultrasonic wave flowmeter in still water

时差式超声流量计广泛应用于工业生产和日常生活各个领域,其中超声信号在流体中顺、逆流传播时间差的测量精度很大程度上决定了流量的测量精度,由于实际测量中"零点误差"和"温度漂移"的存在,使得消除或抑制这两者的影响成为提高流量测量精度的重要环节。依据电声互易定理,改善测量系统电路的互易性可以有效抑制"零点误差"和"温度漂移",而发射电路与接收电路阻抗的对称性和测量系统的互易性存在很强的联系,通过匹配激励和接收电路等效阻抗可以改善测量系统的互易性。依据互易电路设计对现有测量系统进行了改进,并搭建实验平台进行了实际测量。实验表明:此电路设计能够非常有效的抑制"零点误差"和"温度漂移"。

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＂.