煤自燃倾向性的氧化动力学测定中温度测量电路设计

Design of temperature measurement circuit in oxidation kinetics testing for coal spontaneous combustion tendency

在煤自燃倾向性的氧化动力学测定过程中需要对温度进行高精度的测量并记录。为了满足测温要求,选用高分辨率AD转换器AD7714及三线制Pt100热电阻作为温度传感器构建了温度测量电路;为解决器件非线性度引起的输入、输出为非严格线性关系的问题,采用分段线性插值方法对输出值进行插值运算。实验结果表明,该温度测量电路的AD采样分辨率为0.006 7℃,满足设计要求,且实验数据具有很高的稳定性和可重复性。

High-precision measurement and record for temperature is needed in oxidation kinetics testing for coal spontaneous combustion tendency. Therefore, temperature measurement circuit was designed with high-resolution AD converter AD7714 and three-wire Pt100 thermal resistance as temperature sensor; method of piecewise linear interpolation is adopted for interpolation operation of output value to solve problem of non-strict linearity between input and output caused by nonlinearity of devices. The experiment result shows that AD sampling resolution of the circuit is high up to 0. 006 7℃, meeting design requirements, and the experiment data has high stability and repeatability.