带温度测试模块的TDR测试系统研制及温度校准

研制出带有温度测试电路的时域反射仪(TDR)土壤参数测试系统,该系统能够实时监测被测土壤温度;设计了应用于TDR测试系统的土壤温度测试电路;利用该TDR系统采集土壤样本在不同温度下的TDR波形;研究了温度变化对TDR测试波形的影响;反演土壤体积含水量和体积电导率随温度变化趋势.给出了此TDR测试系统测量得到的土壤含水量温度修正公式和土壤体积电导率与测量样本温度变化的关系.带有温度测试模块的TDR测试系统能够扩大TDR应用范围,提高土壤含水量的测量精度.

The Design of Time Domain Reflectometry with Temperature Measurement Circuit

A TDR test system is developed with a temperature test circuit. The temperature test circuit is designed to monitor the soil temperature under TDR test. TDR waveforms are collected at different temperatures with the TDR system. The relationship of soil samples electronic conductivity and temperature is expressed in this study. The measured results show that the measured volumetric moisture content and conductivity are related to the soil temperature. The new revised formulas of water content is expressed by experiments. The system with temperature measurement circuit can extend its scope of TDR application. The measurement results of water content can achieve more accurate results after temperature compensation.