1/4桥应变测量系统在温度影响下的误差分析

温度变化对应变测量的误差有很大的影响,特别是大规模应变测量广泛采用的1/4桥,因无法进行桥路温度补偿,受温度变化的影响更加显著。如果对每个通道使用半桥温度补偿,则操作复杂,成本高,效率低,所以有必要分析温度变化对1/4桥路测量误差的影响。通过分析应变测量时普通应变片和温度自补偿应变片的热输出原理,以及导线和应变采集器受温度的影响,最终给出在多通道采集系统上使用BE系列普通应变片和温度自补偿应变片时,整个采集系统在温度影响下的测量误差,解决了在结构强度试验中温度变化引起的测量系统误差评定问题,并给出不同温度变化范围内满足1%测量误差所需测量应变的理论计算最小值。

Error analysis of strain measurement system using quarter bridge under the influence of temperature

The temperature change has a great influence on the error of the strain measurement. Especially, the quarter bridge is widely used for large scale strain measurement, because the bridge temperature compensation can not be carried out, and the influence of temperature change is more significant. If the use of half bridge temperature compensation for each channel, the operation is complex, high cost, low efficiency, it is necessary to analyze the error of quarter bridge when temperature changes. In this paper, by analyzing the heat output principle of ordinary strain gauges and temperature self compensating strain gauges for strain measurement, the influence of wires and strain gauges on temperature, then given the error of the whole measurement system under the influence of temperature when using the application of BE series ordinary strain gauges and temperature self compensation on multi channel acquisition system. The research solves the problem of error assessment of measurement system caused by temperature change in structural strength test, and determines the minimum value of the measured strain required to meet the 1% measurement error in different temperature range.