Thermocouple calibration - How to Answered
I have a few questions about the thermocouple calibration.
I want to use three type R thermocouples to measure the temperature during a 3d printing process using an Arduino Uno and the max31856 amplifiers. Right now I am doing tests with K type thermocouples before we buy the R-types. It seems to work fine, it measures a room temperature of 22ºC more or less and reacts reasonably in my opinion but I would like to know if the measured temperature is the actual temperature.
1. Is a calibration needed? I know the amplifiers (max31856) do some corrections automatically, but maybe an extra calibration is needed.
2. If such a calibration was needed, how would I do it? For example, I will put copper in an oven and heat it and measure the temperature with my thermocouples and with a bolometer. If my thermocouples measure something different, how do I correct it? Theoretically my program transforms (via amplifiers) the measured tension difference into temperature, correcting it at the junction. How would I tell it now that it has to measure differently?
3. If no calibration is needed and, as I explained in 2, my thermocouples measure something different as the bolometer, which one is the accurate?
Thank you very much for your help.