The measurement uncertainty in the calibration of a thermometer depends on the calibration method used, the uncertainty contri

u_TrInt: uncertainty component due to interpolation of reference function

2. 
   Uncertainties linked to instrument under calibration - Tc
   

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  u_Tca: repeatability of measurements during a calibration. We assume at least 50 measurements of instrument under calibration was made at each calibration point. Standard deviation of mean is calculated.
  

Example: u_Tca= 0.002°C

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  u_Tch: uncertainty component due to hysteresis. In general, hysteresis is a phenomena that results in a difference in an items behavior when approached from a different path. In
  

PRTs, thermal hysteresis results in a difference in resistance at a given temperature based on the thermal history to which the PRT was exposed. More specifically, the resistance of the PRT will be different when the temperature is approached from an increasing direction vs a decreasing direction, and the magnitude of the difference will depend on the magnitude of the temperature excursion and the design of the PRT.

Example: u_Tch=0.002°C

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