I am conducting few trials for checking the placement of a thermocouple on a valve for measuring the temperature of the valve and the material is an X45 alloy. You can see the slot taken on the valve and the thermocouple is inserted in the slot (picture is attached).
Turned on the muffle furnace with a set point of 300 deg C
After the furnace temperature is stable at 300 deg C, kept the valve inside the furnace.
Kept the valve inside the furnace and let it attain an equilibrium.
Took the valve outside after set amount of time and measured the temperature using a microcontroller (arduino + MAX6675). IT took about 10 seconds to measure the temperature and I could not run the wires inside the furnace as I did not have access to high temperature withstanding cables for the thermocouple. Also, as the valve is taken out for measuring the temperature, there will be some heat loss due to atmospheric exposure.
After 2 hours of this trial, I found the temperature of the material to be around 250 deg C.
Due to the huge difference between setpoint and the material temperature, I wanted to raise a question.
NOTE: The thermocouple and the furnace are calibrated.
My question is, if a material is placed in a furnace with a setpoint temperature, would the temperature of the material be same as the setpoint after a certain amount of time? My guess is there will be some temperature difference but since I am not a mechanical engineer, I want to clarify this in this wonderful forum.