[madmaxx]

+/_ 3% if you are shooting with an emissivity of 1. To get a emissivity of 1 paint a black circle where you are taking your temp and hold as close as possible.

It is sooooo easy to test. Remove sensor let it hang. Boil water in kitchen, take pan to car and put probe in, you will not loose but a couple degrees of temp in your pan, then monitor temp on the way down. I hate to tell, gauges are painfully accurate or at least mine is.