| Zugriffsnummer | 19984 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | On secondary representations of the second |
| Autor(in); Institution |
Gill, P.; National Physical Laboratory (NPL), Teddington, UK
Riehle, Fritz; 4, Optik, PTB-Braunschweig
|
| Quelle/Jahr | Proceedings of the 20th European Frequency and Time Forum:(2006), 282 - 288 |
| ISBN | 3-9805741-8-0 |
| Verlag | Braunschweig: Physikalisch-Technische Bundesanstalt |
| Konferenzangaben | 20th European Frequency and Time Forum (EFTF), Braunschweig, 27-30, March, 2006, Germany |
| Zusammenfassung | The emergency of microwave and optical frequency standards with accuracies close to those of caesium primary frequency standards has led to the concept of secondary representations of the second. The recently-formed Joint Working Group of the CCL / CCTF has now recommended as secondary representations to the CCTF / CIPM one microwave radiation in 87Rb and three optional 199Hg+, 88Sr+ and 171Yb+. This paper describes the rationale, evolution and development of criteria for acceptance of a radiation as a secondary representation, together with a review of the JWG assessment and recommendation of the four radiations already proposed. |
