Diagram 1.0
First of all, we determine the ‘Tolerance’ based on Unit Correction Value. We look for the temperature accuracy from the unit specification and compare with the calibration results. Based on Diagram 1.0, Let’s say If the unit specification accuracy is +/- 0.5°C, the correction value read in calibration certificate is +/- 0.35°C. Thus, it is ‘In-Tolerance’ or fit to use. If correction value read in calibration certificate is +/- 0.65°C, it is consider as ‘Out-of-Tolerance’ or not fit to use.
Besides, the another way to determine the ‘Tolerance’ is based on Measurement Uncertainty. The measurement uncertainty is the combination of all or most of the possible sources of errors that the unit can receive or encouter. Thus, we use the measurement uncertainty as the basis for tolerance. Since the measurement uncertainty is usually very small and will result in a strict tolerance, the possibility of a failed result is higher.