Check the thermocouple temperature meter method

Inspect the site of the thermocouple temperature meter method in the use of the thermocouple cold junction temperature is impossible is equal to 0 degrees Celsius, most display instrument with the cold end temperature automatic compensation function. So short checking method is usually adopted to the input end of the display instrument, observe whether the display value to room temperature, if the instructions for the room temperature, instrument basic is normal. Room temperature is popular argument, of course, strictly speaking short after input instrument display value is instrument input terminal near the environment temperature. When the operator of the instrument shows temperature when in doubt, can use dc potentiometer or other standard table, measuring thermocouple thermoelectric potential UX first, and then according to the reference end, or at room temperature, thermocouple indexing table, get the temperature of the thermoelectric potential UO, then put the UX and UO together, get the overall thermoelectric potential, check thermocouple indexing table get real temperature is measured. If you have a S degree of thermocouple, measured the thermocouple thermoelectric potential UX is 12. 94 mv, room temperature 28 degrees Celsius, look-up table UO = 0. The 161 mv, UX + UO = 12. 94 + 0. 161 = 13. 101 mv, thermocouple indexing table, actual temperature for 1295. 2 c. 4, check the heat resistance temperature instrument method when the operators of the instrument shows the temperature when in doubt, can use dc resistance bridge or other standard table, measure the heat resistance of the resistance, check the heat resistance indexing table, get the resistance of the temperature, can judge the error of the instrument. Also can use dc resistance bridge instead of heat resistance, to display the input resistance to check the display, to determine whether the instrument is normal. This operation is belong to the category of calibration; When poor contact thermal resistance or wires, instrument display temperature will be on the high side. If there is a low is likely to be short circuit.