I think this method may work to test the actual temperature reading of your Temp control mods..

Concidering most mod atr not that accurate...

I use a tool that reads tempertures without contacting the evice...this tool has been used for checking the temperatures exhaust systems of cars and trucks..as well are ambiant room temperatures ..detected by a laser beam dirrected at objects,,

Just a way to double check the accuracy of the temperature control settings on your TC mod boxes ..

The device isnt that expensive...some costt as little as 15 dollars up to 40 dllars found at hardware and auto parts stores..

What i do is turn my mod box to a certain temperature..[then aiming the red laser dot at the heated mesh setting].... and duble check the temperature readings against the radings on the wireles laser temp senor...

photos below of device...