激光调制法的热电偶时间常数测量

Time Constant Measurement of Thermocouple by Modulated Laser

在瞬态温度测量中,为了获得准确的测量结果,要求测温传感器有良好的瞬态响应特性,时间常数是反映瞬态响应的参数之一.本文建立了热电偶时间常数测量系统,建立并分析了热电偶瞬态响应的数学模型;用美国相干公司K-500型CO2激光器测试了几种不同热电偶的时间常数.结果表明,利用此大功率高频调制CO2激光脉冲作为激励源,可以测量时间常数为亚毫秒量级的热电偶及其它表面温度传感器.

In transient temperature measurement, temperature sensor should have excellent transient characteristic for acquiring accurate result. Time constant is one of transient responding parameters. So time constant measurement system is founded and composition of the system are mainly given, the transient responding model of thermocouple is developed and analyzed. This system is used to test time constant of several different kinds of thermocouple by coherent K-500 CO2 laser. The experimental results have shown that the high frequency modulated and high power CO2 laser as the exciting source can be used to measure thermocouple or transient surface temperature sensor with a time response of the submillisecond order.