Solution to the temperature drift of the static water time difference of ultrasonic flow meter
2019-09-18 17:19:24

The flowmeter is used to measure and display the total flow of fluid through specific regions of the instrument, the ultrasonic flowmeter with respect to mechanical and electromagnetic flowmeter has the advantages of low cost, small pressure loss, easy to plug, is widely used. Time difference ultrasonic flowmeter by measuring the ultrasonic propagation time in fluid countercurrent flow calculation, in which, the propagation time of the ultrasonic signal, the countercurrent flow calculation, the measurement accuracy of the ultrasonic signal, current propagation time difference determines the performance of flow measurement. In the measurement of water flow as an example, in the static case, measured clockwise and current propagation time difference theory should be 0, but still in practical situations are often not for the 0 time, the measurement error of the resulting called "zero error". Zero error always exists in the measurement, usually by the measurement system is "dry" calibration to eliminate the hydrostatic, however in the same system, the temperature change is large, the characteristics of ultrasonic transducer will change with temperature, it will change the frequency and envelope of the received waveform, thereby causing zero error and flow measurement the results of temperature drift. Stability of temperature drift will not only seriously influence the results of measurement, but also makes the "zero error of dry calibration failure, therefore, reduce the static zero error and temperature drift is an important link to improve the accuracy of flow measurement.