uTrc: standard uncertainty in the calibration of the reference standard. It presents information on expanded uncertainty of reference standard in the appropriate temperature range. It calibration certificate of reference standard holds information on corrections, then they should be applied but normally only expanded uncertainty is calculated:
Example: calibration expanded uncertainty: 0.020 °C (k=2)
uTrd: standard uncertainty uTrd is estimated from the maximum drift over all the drift values between successive calibrations. If instrument is new one, the manufacturer’s data for stability is taken into account for uncertainty budget calculation. If no manufacturer’s data is available the drift is estimated as standard uncertainty in the calibration of reference standard.
Example: drift between calibrations is 0.010 °C (k=2)
