One method I've found is putting the thermocouple in an ice bath, then boiling water and plotting actual temperature vs. measured TC temperature. A linear curve fit is then applied between the two reference points, and used in a DAQ program to 'correct' the TC measurement coming into the DAQ. But then I've also read about just using a conversion equation from TC output voltage to temperature, with the specific polynomial coefficients being dictated by the type of TC. I have a limited knowledge of DAQs, but assuming a program like labview could measure either temperature or output voltage from a TC, couldn't you just use the output voltage with the conversion equation to get a reading of temp? If this is the case what would be the purpose of using a calibration method as described above?