| Zugriffsnummer | 53161 |
| Dokumenttyp | Konferenzartikel |
| Peer Review | unbekannt |
| Sprache | Englisch |
| Titel | Drift behavior of old triple point of water cells |
| Autor(in); Institution |
Xiaoke, Yan; National Institute of Metrology (NIM), Beijing, CHINA
Meng, Zhejian; China Jiliang University, Hangzhou, CHINA
Qiu, Ping; National Institute of Metrology (NIM), Beijing, CHINA
Zhang, Jintao; National Institute of Metrology (NIM), Beijing, CHINA
Yuning, Duan; National Institute of Metrology (NIM), Beijing, CHINA
Wang, Wei; Henan Agricultural University, Zhengzhou, CHINA
|
| Quelle/Jahr | ITS10 Conference Digest - Tenth International Temperature Symposium, Anaheim, CA USA, April 3-7, 2023:(2024), 15 S. |
| Artikelnummer | 050003 |
| DOI | |
| Konferenzangaben | 10th International Temperature Symposium (ITS10), Anaheim, Calif., 03-07, April, 2023, USA |
| Zusammenfassung | The triple point of water (TPW) is realized in cells made of borosilicate glass or fused silica. Due to the gradual dissolution of glass components by leaching and etching processes, impurities from glass containers can dissolve into the inner melt, resulting in an increase of the impurity concentration at the phase boundary and of the density of water. As a result, increasing impurity-induced temperature depressions with age were observed in old TPW cells. However, some old cells from the National Research Council of Canada (NRC) seemed to remain stable for many years. This is an enigma regarding old TPW cells, inspiring us to perform research on the long-term drift of TPW cells to solve this enigma. As a result, a joint investigation between NIM and PTB was undertaken to compare TPW cells with different origins and production dates ranging from 1974 to 2021. After preparation of the ice mantles in the cells, continuous measurements of the resistances of standard platinum resistance thermometers (SPRTs) in the cells were made until the observed equilibrium temperatures were stable for 10 days. Through the comparisons between the old cells and newly manufactured reference cells, the drift behavior of cells with different ages was determined. Due to the initial segregation and a subsequent diffusion of impurities during the preparation and operation of the cells, the impurity concentration within the inner melt was increasing over time, leading to a depression in the temperature of the triple point and an increase in the hydrostatic pressure correction coefficient. Most old cells needed about 15 days for stabilization within 0.04 mK after the formation of the ice mantles. Therefore, seven days to be aged after preparation of the ice mantles in the old cells are not sufficient. |
