1. Use a DC electronic potentiometer for calibration; the meter should be powered on before calibration.Vacuum heat treatment of slender hollow parts Warm for half an hour, first calibrate the standard. 2. Place the temperature measuring instrument to be calibrated in a horizontal position, and connect the calibration circuit according to the regulations. 3. Determine the calibration temperature according to the graduation number of the temperature instrument, generally should focus on selection Commonly used temperature measurement points.Vacuum gas Quenching of 45CrNiMo1VA Steel Spinning Mandrel 4. Set the DC electronic potentiometer switch S to "output", according to the measured temperature The millivolt value of the point determines the output value of the calibration meter. 5. Toggle the key board switch to "unknown" for verification, and adjust the temperature meter of zero.Vacuum quenching of KMN steel structure 6. During daily use, no one may arbitrarily adjust the zero point of the temperature meter value.