自然热电偶标定方法的研究

Study on Calibration System of Nature Thermocouple

针对自然热电偶法测量切削温度时,热电偶的标定过程繁琐、数据处理复杂等问题,采用标准K型热电偶箱式电热炉,把刀具和工件材料焊接在一起放入其中,通过改变炉内温度模拟切削温度变化,用放大电路对温差电动势进行放大处理,经过iUSBDAQ-U120816数据采集卡,输入到计算机,利用iDAQTest&Log软件,对电压信号在线采集、保存,再进行非线性回归法数据处理,可得到热电偶的标定曲线和拟合公式。试验表明:该方法可以替代热电偶专用标定设备,具有设备简单,操作方便,数据准确可靠的优点,为切削温度的测量提供了依据。

Considering such problems as cumbersome calibration process, complex data processing, etc, when measuring the cutting temperature by mothod of the natural thermocouple, the welded tools and workpiece materials were put into the standard K--type thermocouple box furnace. We simulated the cut- ting temperature by changing the temperature in furnace. The thermoelectromotive forces amplified were input into computer through the iUSBDAQ--U120816 data acquisition card. Using the iDAQTest^Log software, voltage signals were collected, saved and processed by nonlinear regression. Finally, we got the thermocouple calibration curve and fitting formula.