| Zugriffsnummer | 46216 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | Highly-accurate second-virial-coefficient values for helium from 3.7 K to 273 K determined by dielectric-constant gas thermometry |
| Autor(in); Institution |
Gaiser, Christof; 7.4, Temperatur, PTB-Berlin
Fellmuth, Bernd; 7.4, Temperatur, PTB-Berlin
|
| Quelle/Jahr | Metrologia: 58 (2021), 1, 7 S. |
| Artikelnummer | 015013 |
| ISSN | 0026-1394 (PRINT) ; 1681-7575 (ONLINE) |
| DOI | |
| Verlag | Bristol: IOP Publishing |
| Zusammenfassung | Since the redefinition of the base unit kelvin via fixing the Boltzmann constant in 2019, it hasbeen possible to realise the unit applying different gas-thermometry methods in accordancewith the ‘Mise en pratique for the definition of the kelvin in the SI’. For this application, theuse of data for the gas properties resulting fromab initiocalculations is of special interestbecause it makes primary thermometry mucheasier. But since a rigorous estimation of theuncertainty of theoretical calculations is at least very complex, if not impossible, a check ofthe results by a comparison with highly-accurate experimental values is mandatory. Such acheck is performed for the second virial coefficient of helium, which is a widely usedmeasuring gas, in the temperature range from 3.7 K to 273 K. For obtaining highly-accuratesecond-virial-coefficient values (relative uncertainty at a few tenth of a percent level or evenbetter), isotherms were measured with the PTB dielectric-constant gas thermometer. Thehighly-accurate isotherm data were evaluated by fitting, applying an extended workingequation for the dependence of the gas pressure on the dielectric constant. The comparison with the results of the latest ab initio calculations shows coincidence within the combineduncertainty estimates. |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY 4.0 ; Creative Commons Attribution 4.0 License |