Establishing a thermometry calibration lab: equipment requirements, levels of accuracy

摘要

This paper provides a brief overview of the standards and equipment typically used in a thermometry calibration laboratory and gives rough estimates of the accuracies that can be achieved with different types of equipment. It is intended to assist those who are new to the field of thermometer calibration who intend to establish such a calibration facility. The apparatus required to calibrate commonly used contact thermometers such as platinum resistance thermometers (PRTs), thermocouples and liquid-in-glass thermometers, as well as radiation thermometers, at different levels of accuracy is discussed. Special requirements for the calibration of certain types of thermometers are also mentioned. By comparing the contributions to the uncertainty of measurement of different components of the calibration system (e.g. reference PRT, resistance measuring instrument, temperature block calibrator, thermometer under test), components can be chosen so as to achieve the required accuracy in an efficient manner, and planning for future upgrades of the calibration system is facilitated.