Bilateral comparison in fixed points of Zn, Sn, Ga and Hg

Project Description

This bilateral comparison is intended to compare PTB and LPM-FSB realization of the ITS-90. The range of temperature covered in this comparison is from the triple point of Hg (234,3156 K) to the freezing point of Zn (692,677 K). The transfer standards used will be long-sterm SPRT. It will be calibrated in both laboratories and W value will be compared.

Final Report 2014-02-25

The objective of this project is to compare realizations of Triple point of Hg (-38.8344 °C), Melting point of Ga (29.7646 °C) and Freezing points of Sn (231.928 °C) and Zn (419.527 °C) between PTB and HMI/FSB-LPM using long stem 25 ohm standard platinum resistance thermometer (SPRT). Brand new quartz sheathed SPRT has been calibrated at PTB, and then carefully shipped to HMI/FSB-LPM where second set of measurement was made. Results of the intercomparison showed satisfactory performance of the Ga, Sn and Zn cells of the HMI/FSB-LPM, while Hg cell was found to be broken.