New NIST Mercury Triple-Point Cells

Published

June 1, 2001

Author(s)

Gregory F. Strouse, J Lippiatt

Abstract

Six new Hg triple-point (TP) cells (234.3156 K) were manufactured in the NIST PRT Laboratory for use in the realization of the International Temperature Scale of 1990 (ITS90). The fixed-point cells consisted of both glass and stainless steel designs with either an 8 mm or 12 mm inner diameter reentrant well. Triple-distilled Hg with nominal purities of 99.999 999 wt.% were used to fill the cells using a vacuum distillation filling process. The certification method of the new cells included measuring melting curve plateaus, direct comparisons with the PRT Laboratory reference Hg TP cell (Hg SS-1), and immersion profiling. The estimated amount of impurities leached out of the stainless steel crucible into the Hg sample of Hg SS-1 over 25 years was found to be 1 g/g. This paper presents the fixed-point cell designs, fabrication method, results from the cell certification procedures, and the estimated uncertainty assigned to the Hg TP cells.

Proceedings Title

International Sympoisum on Temperature and Thermal Measurements in Industry and Science | 8th | | VDE

Conference Dates

June 1, 2001

Conference Location

Berlin, GE

Conference Title

TEMPMEKO

Pub Type

Conferences

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Keywords

HgTP, HgTP cell, ITS-90, SPRT, Temperature, Thermometry

Citation

Strouse, G. and Lippiatt, J. (2001), New NIST Mercury Triple-Point Cells, International Sympoisum on Temperature and Thermal Measurements in Industry and Science | 8th | | VDE, Berlin, GE, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=830738 (Accessed December 2, 2024)