压力传感器膜片表面温度的测量和分析计算

用红外热成象技术测量应变式压力传感器工作时的膜片温度分布,以判断由于电阻应变片工作时温度变化对测量准确性的影响。测量中为获得应变片的真实温度,作了表面喷黑处理。对于实用的3MPa和0.6MPa的压力传感器,在不同工作介质(空气和变压器油)及工作电压条件下进行了测量,其结果表明:应变片表面温度随工作电压增高而加大,且不均匀。以空气为介质的温度高于以变压器油为介质的温度。据此可以确定对压力测量准确度的影响。还用有限差分方法对压力传感器膜片表面温度作了数值分析计算。

Measurements and analyses of diaphragm temperature of pressure sensor

Diaphragm temperature distribution of pressure sensor was measured by means of a infrared video system in order to examine the effect of the temperature change of the resistance strain gauge on its measurement accuracy. The diaphragm was blackened, then its true temperature distribution can be obtained by the infrared imagine. For the pressure sensor at ranges of 3MPa and 0.6Mpa, measurements were made under conditions of different values of voltage in mediums of air and transformer oil. The results indicated that strain gauge temperature increased with the voltage value and it was nonuniform. The temperature of the sensor with air as a medium is higher than that with oil. According to these results the effect on the accuracy of pressure measurement can be determined. A FDM numerical analysis of the diaphragm temperature field of the pressure sensor is also presented in this paper.