High-accuracy measuring system of soil temperatures was designed. Thermocouple was used as temperature sensors. Under the control of the micro-controller, high-accuracy and automatic detection was achieved to analyze the impact of soil temperature on water and heat of soil. The system was studied from three aspects, such as hardware circuit, software and curve fitting. By using the electric bridge method for temperature acquisition, least squares method was used to piecewise fit samples values and temperature. Their relationship curve was described. The measurement error was compensated and corrected to ensure the measurement precision. The result showed that the experimental absolute error was less than 0. 02℃.%为分析土壤温度对地层水热参数的影响,以热电偶为测温传感器,设计了单片机控制的高精度土温测量系统.从硬件、软件曲线拟合算法等方面进行了研究,温度采集采用电桥法,并用最小二乘法对采样值与温度进行分段拟合,描绘出采样值与温度关系曲线,对测量误差进行了修正和补偿.结果表明:系统的实验测量绝对误差低于0.02℃.
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