THERMOCOUPLE INSPECTING METHOD

PURPOSE:To improve reliability of inspection, by judging the result of inspection based on the differences of measured temperatures between secondary thermocouples and a standard thermocouple. CONSTITUTION:The electromotive force generated in a standard thermocouple 14a is supplied to a regulator 20 as a temperature signal in a furnace ST 1. The regulator 20 controls the temperature of a heater 12 based on a furnace- temperature control signal CT from a computer CPT 22. In a difference detecting circuit 28, the differences between the electromotive force of the thermocouple 14a and the electromotive forces generated by secondary thermocouples 14a and thermocouples 14c to be inspected are detected. The differences are inputted to the CPT 22 as difference signals SS through an amplifier 32. Meanwhile, under the state the temperature in an inspecting furnace 10 is kept at each value, the difference signals SS are corrected by errors due to the thermocouple 14a and 14b. The accuracy of the measured temperature of each thermocouple 14c is judged based on whether the value is within the allowable error or not. The result is displayed on a CRT 34 and output to a printer 36. Thus an operator judges the result of the inspection of the thermocouple.