Detailansicht
Star intercomparison of sealed triple-point cells filled with cryogenic gases. Part II: Data
PTB-Berichte. Thermodynamik - Wärme (W) 11
ISBN/EAN: 9783956065125
Umbreit-Nr.: 9541757
Sprache:
Englisch
Umfang: 40 S., 5 farbige Illustr., 14 s/w Tab., 19 Illustr
Format in cm:
Einband:
kartoniertes Buch
Erschienen am 19.06.2020
Auflage: 1/2020
- Zusatztext
- An overview of the results of an international star intercomparison of low-temperature fixed points is given. Between 1997 and 2005, 64 sealed triple-point cells (STPCs) of twelve metrological laboratories worldwide have been investigated at PTB: Conservatoire National des Arts et Métiers/Institut National de Métrologie (LNE-INM/CNAM), Instytut Niskich Temperatur i Badan Strukturalnych, Polska Akademia Nauk (INTiBS), Istituto Nazionale di Ricerca Metrologica (INRIM, formerly Istituto di Metrologia "G. Colonnetti" (IMGC)), Measurement Standards Laboratory (MSL), National Institute of Metrology (NIM), National Institute of Standards and Technology (NIST), National Metrology Institute of Japan (NMIJ), National Physical Laboratory (NPL), National Research Council (NRC), PhysikalischTechnische Bundesanstalt (PTB), Van Swinden Laboratorium (VSL), All-Russian Scientific Research Institute of Physical Technical and Radio-technical Measurements (VNIIFTRI). The STPCs are used to realise the triple points of hydrogen, neon, oxygen, and argon, respectively, as defining fixed points of the International Temperature Scale of 1990, ITS-90. The melting curves of all STPCs have been measured on the same experimental equipment, adhering strictly to a single measurement program, which is described in the PTB Report PTB-Th-4 "Star intercomparison of sealed triple-point cells filled with cryogenic gases, Part I: Protocol". This protocol enables separation of the effects influencing the melting curves and direct comparison of the thermal behaviour of the STPCs, which are quite different with respect to design, age, gas source, and filling technology. In this second report, special em-phasis is given to the typical properties of the four fixed-point substances, to the spread of the liquidus-point temperatures and to the uncertainty of their determination. Connections between the star intercomparison and other international activities, including CIPM Key Comparisons, are also discussed.