Thermocouple Dynamic Errors Correction for Instantaneous Temperature Measurements in Induction Heating

Abstrac t The most commonly used thermometer to measure high temperatures in metallurgy is the thermocouple, but because of its long response time it can be used mainly for measuring time-averaged temperatures. Research on steel wire patenting using inductive heating required instantaneous temperature values. Pyrometers or thermographic cameras could be used, however they are generally expensive, and temperature measurements are not always reliable due to differing emissivities. In described case expensive infrared thermometers could be replaced by cheap thermocouple provided that dynamic errors were corrected. Correction algorithm would not increase the total cost of the measuring system as no additional hardware is required. Correction algorithm was implemented in LabVIEW. The time constant was determined experimentally. Experiments were carried out to examine improvement in response time of thermocouple with correction algorithm.