Non-Thermometric Factors Affect the Performance of Traceable Temperature Measurements

Abstract

A progressive study on the non-thermometric factors that affect the thermometry measurements have been studied. There are several non-thermometric factors affect directly the value of TPW fixed point. In this paper, the investigation was carried out on four main sources, which are the vibration of the maintenance bath, the stability of standard resistor, thermometer self-heating and the frequency of triggering the resistance value form the thermometry bridge. The successful evaluation of the non-thermometric contributions depends on a detailed knowledge of the calibration process. The uncertainty of the measurements is coming from the reference standard, in our case standard platinum resistance thermometer (SPRT), the measuring equipment used and the characteristics of the device under calibration. Uncertainty contribution from the thermometric and non-thermometric sources has been established. It has noted from the results that the limited contribution related to the non-thermometric sources has been handled to be less than 2 mK ± 0.3 mK.