Physics:Provisional Low Temperature Scale of 2000
The Provisional Low Temperature Scale of 2000 (PLTS-2000) is an equipment calibration standard for making measurements of very low temperatures, in the range of 0.9 mK (millikelvin) to 1 K, adopted by the International Committee for Weights and Measures in October 2000. It is based on the melting pressure of solidified helium-3.[1]:11.3[2][3]
At these low temperatures, the melting pressure of helium-3 varies from about 2.9 MPa to nearly 4.0 MPa. At the temperature of approximately 315 mK, a minimum of pressure (2.9 MPa) occurs. Although this gives a disadvantage of non-monotonicity, in that two different temperatures can give the same pressure, the scale is otherwise robust since the melting pressure of helium-3 is insensitive to many experimental factors.
See also
- International Temperature Scale of 1990 (ITS-90) — the calibration standard used for all temperatures above 0.6 K
- Leiden scale
References
- ↑ Pobell, F. (2007). Matter and Methods at Low Temperatures (3rd ed.). Springer. ISBN 978-3-540-46356-6.
- ↑ "The Provisional Low Temperature Scale from 0.9 mK to 1 K, PLTS-2000". International Bureau of Weights and Measures. http://www.bipm.org/utils/en/pdf/PLTS-2000.pdf.
- ↑ "Supplementary Information for the ITS-90". International Bureau of Weights and Measures. http://www.bipm.org/en/publications/mep_kelvin/its-90_supplementary.html.
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