Measure the response time of the thermocouple1

Thermocouple as the temperature of a typical instrument, has wide application in industry.

the measuring thermocouple thermal response time is actually more complex, different test conditions will produce different measurements, because it is affected by the heat transfer rate of thermocouple with surrounding medium, heat transfer rate is high, the thermal response time is short.

in order to make the temperature meter thermocouple products comparable thermal response time, national standards: thermal response time should be in the special flow test device. Of flow velocity in the device should keep 04-005 ms, the initial temperature in 5 - Temperature 45 ℃, within the scope of the step value of 40 - 50℃。 In the process of test, the water temperature should be no greater than temperature step value plus or minus 1%. The subjects of the thermocouple placement depth of 150 mm in depth or design.

the B type thermocouple near room temperature thermoelectric power is small, thermal response time is not easy to measure, so can use the same specification of national standard of the S type thermocouple electrode component to replace its own hot electrode components, and then tested.

test should record the change of the thermocouple output to the equivalent of 50% of the time temperature step change T05, when necessary record 90% 10% of the thermal response time T01 and changes of T09 thermal response time. Recorded by the thermal response time, should be the same test at least three times the average of the test results, each measurement results for the average deviation should be within + / - 10%. In addition, the time needed for forming temperature step change should not be less than one over ten of the is test thermocouple T05. The response time of the recording instrument or instrument should not exceed one hundred percent of the participants thermocouple T05.