电涡流间隙传感器的温度补偿

电涡流间隙传感器具有无接触测量、动态响应快和适应性好等特点,应用领域十分广泛,缺点是温度漂移较大。介绍了电涡流传感器工作原理,并分析了温度漂移的主要因素。建立了检测线圈的数学模型,通过温控试验证明了数学模型的正确性;利用差分方式抵消了检波电路参数的温度漂移,提高间隙信号输出的稳定性。通过试验对检测线圈和检波环节补偿电路进行验证,得出温度-检测线圈输出电压曲线,将补偿前和补偿后试验结果进行对比,满足JJG 644-90标准要求,温度漂移小于12.1%,证明了补偿方法的有效性。

Temperature compensation of eddy current sensor

Eddy current transducers are widely used because of its untouchable detecting, fast dynamic response and better adaptability, but it has great temperature drift. The principle of the eddy current transducers are discussed ,and the mainly reasons resulted in the temperature drift are analyzed. Mathematical model detecting coil is given,accuracy of model is proved by test in thermostat ;the demodulation-circuit parameter temperature drift is counteracted ,the stability of the output gap signal is improved. Proved the compensation circuit of detecting coil and demodulation by test, curve of the temperature and voltage of detecting coil output is achived. Contrasting the curves with and without compensation, result is satisfied of the national standard JJG 644 - 90, the temperature drift less than 12.1% ,the compensation is effective.