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

u_{bath h}: Spatial homogeneity is a gradient is observed as a change of a temperature reading of a thermometer according to a change of its position inside a calibration bath.

• 
  Basic gradients that can be observed are vertical and horizontal gradient but
  
• 
  sometimes more appropriate to define axial and a radial gradient. Uncertainty contribution of an axial gradient is determined as maximum temperature difference between two different positions in axial direction. The radial gradient is a maximum temperature difference between two different positions in a radial direction.
  

Example:

•