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

Uncertainties components linked to temperature bath - Tbath

The spatial and tempo­ral temperature distribution in the working space of temperature stabilized bath must be quantitatively determined and taken into account for uncertainty budget evaluation. Method for the determination of the temporal and spatial distribution involves calibrated thermometers of identical type, positioned on the boundaries of the working space (horizontal, vertical) of the temperature bath. After thermal stabilization, the temperatures measured with the thermometers are continuously recorded (typically over a period longer than 30 min). The

maximum tem­perature difference between the thermometers is used for as uncertainty component in the uncertainty budget (rectangular distribution).

Temperature gradients in temperature-stabilized baths or furnaces can be reduced by provid­ing a metallic stabilizing block with holes to accommodate the standards and calibra­tion items. The thermometer calibration may begin after both the temperature is stabilized bath and the thermometer itself have reached thermal equilibrium.

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.

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