This is the second part of my reply on the IFSQN web site in regards to calibrating IR temperature sensors:
This possibly highlights the issues involved.
The calibration device is basically a black metal cup. You point the gun in one end and place a thermometer into the base (literally into the base, not through the base) to measure the temperature of the unit.
So you are talking about incredibly short distances, with no outside interference, and into an enclosed space to stop reflection. With all these conditions met you can make a consistent and reliable reading. Consequently you can “calibrate” your IR unit.
But then a pimply gen-Y takes it into the freezer and plays Star Wars shooting it across to the other side. Or it is pointed at the plastic wrapped ice-cream pallet which will reflect or give you the surface temperature of the wrapping.
The standards state that 1° accuracy or better is required within the food industry. This can easily be met by good IR guns, the problem is that the user needs to know their limitations and work within them.
Personally I think they are a great lazy check. It would be great to hear when people are prepared to use them and when they aren’t.
And the usual disclosure, I sell temperature loggers. I have previously tried to sell IR sensors but pulled out of the market because of these types of issues.