An algorithm has been developed to evaluate the ‘cali- bration efficiency’ of a sensor. It is applied to a recently developed platinum resistance thermometer. The result shows that the calibration efficiency can be easily estab- lished for typical existing sensors. By comparing the results, as shown in Figure 3, one can establish a common basis for comparison of the calibration efficiency among different kinds of sensors. If the optimum locations for the calibration points, expected errors and deviation functions are available from the supplier of the sensors, the effort needed by the user to perform the calibration will be reduced considerably. Application of the present approach to typical sensors and comparison of the calibration efficiency among them are the next tasks to be undertaken.