Selection technique of thermocouple

1 temperature measurement accuracy and measurement range selection: the temperature at 1300-1800 degrees, and the accuracy requirement is relatively high, usually choose B type thermocouple; requirement of accuracy is not high, the atmosphere allows available tungsten rhenium thermocouple, above 1800 DEG C commonly used tungsten rhenium thermocouple.

The use of temperature at 1000-1300 degrees Celsius required accuracy and high selection of S type thermocouple and N type thermocouple. 1000 C usually choose K type thermocouple and N type thermocouple is lower than 400 DEG C usually used E type thermocouple; 250 DEG C and negative temperature measurement is usually used T type thermocouple. At low temperature, the T thermocouple is stable and accurate.

2 using the atmosphere of choice: suitable for thermocouple strong oxidation and weak reduction atmosphere in use, J type and T type thermocouple is suitable for weak oxidizing and reducing atmosphere, if used to protect the good air tightness of pipe, atmosphere is not too strict.

The choice of 3 response durability and thermal durability of large diameter wire thermocouple is good, but the slow response, the heat capacity of the thermocouple, the response is slow, the gradient of temperature measurement, temperature control, temperature difference. Fast response time requirements and have a certain durability, choose suitable sheathed thermocouple.

4 measurement of the nature of the object and the choice of the state of the thermocouple: moving objects. Vibration objects, high pressure vessel temperature measurement requirements of high mechanical strength, there is a chemical pollution of the atmosphere requires a protective tube, there is an electrical interference in the case of relatively high insulation. Type selection process: Model - index - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - length or depth of.