微细热电偶的制作与时间常数标定方法

Preparation of micro thermocouple and calibration method of time constant

在瞬态温度测量中,为了得到准确的测量结果,要求热电偶具有良好的快速响应特性,其时间常数越小越好。借助于数字显微放大镜观察,以微细铜丝和康铜丝(0.05 mm)焊接制备了快速响应热电偶;为了对时间常数准确标定,采用单片机控制电子开关闭合让激光器立即工作产生瞬时温度阶跃,建立了测定热电偶动态特性的实验系统,并用该系统测定了Cu/Cu Ni快速响应热电偶的时间常数。结果表明,制备的微热电偶响应时间达到(118.8±1.64)ms;利用该系统对时间常数进行标定,结果准确可靠、设备简单、费用低廉,实用性较好。

During transient temperature measurement, performance to achieve an accurate result with the less the thermocouple is required to possess a quick response time constant the better. Therefore, a quick response micro thermocouple is prepared by welding micro copper wire and constantan wire under the observation of digital zoom microscope. And the experimental system of measuring dynamic thermocouple characteristics is established to calibrate the time constant accurately. Also, the time constant of the Cu/CuNi quick response thermocouple is measured with this system. As a result, the response time 8 ±1.64 ） ms, the time constant under calibration with simple, reliable and economic. of the prepared micro thermocouple has reached to （118. this experimental system is accurate, and the device is