Stability of standard platinum cobalt resistance thermometers under hundred low temperature cycling

Abstract:

Standard platinum cobalt resistance thermometers (SPCRTs) are important temperature sensors used in lowtemperature region especially from 0.65 K to 24.556 1 K (triple point of neon), and highstability ones have the potential to be used as the data carrier for temperature calibration and international comparison. Based on our previous research, this article establishes a lowtemperature assessment system with temperature control stabilities of 13 μK at 5 K and 27 μK at 24.556 1 K. It is currently the most stable lowtemperature assessment systems reported in the world. Based on the system, stability of the developed SPCRTs is investigated under hundred lowtemperature cycling from 5 K to 24.556 1 K, and five highstability SPCRTs are obtained. Among them, the stability of four 50 Ω SPCRTs is better than 0.2 mK and the stability of one 100 Ω SPCRT is better than 0.5 mK at 24.556 1 K, which is the best international result for low temperature stability of SPCRTs. In the future, the high stability SPCRTs selected in this article will be used in the relevant applications and research of temperature calibration and international comparison at low temperatures.