You should defiantly check them regurlaly against a known temp. at the temp. range you will be using it. If it happens to be around 32˚F ice water works good for that. If you are measuring higher temps check and calibrate against a higher temp.
From what they say even though they should be calibrated from factory they are sometimes out and yes as slushy as possible lots of ice. Just did one tonight.
Originally Posted by ccut
I've never of calibrating them
You can not calibrate the sensor itself and these type of sensors start to fail with use and age.
If the sensor is displaying out of the accuracy you like it should be replaced.
The "calibrating" is at the meter to get your display to read correctly with the incorrect input. The problem with doing it since the voltage off a thermocouple is not linear to temp is it will just make other temps you are taking off even more. When you "calibrate" it is precise for that one temp only until it drifts out of accuracy again.