Recommendation 1 of the 92nd CIPM (2003)

Revision of the Mise en Pratique list of recommended radiations

The International Committee for Weights and Measures,

considering that

• improved frequency values for radiations of some high-stability cold ion standards already documented in the recommended radiations list have recently become available;
• improved frequency values for the infra-red gas-cell-based optical frequency standard in the optical telecommunications region, already documented in the recommended radiations list, have been determined;
• femtosecond comb-based frequency measurements for certain iodine gas-cell standards on the subsidiary recommended source list have recently been made for the first time, leading to significantly reduced uncertainty;

proposes that the recommended radiation list be revised to include the following:

• updated frequency values for the single trapped ⁸⁸Sr⁺ ion quadrupole transition and the single trapped ¹⁷¹Yb⁺ octupole transition;
• an updated frequency value for the C₂H₂-stabilized standard at 1.54 µm;
• updated frequency values for the I₂-stabilized standards at 543 nm and 515 nm.

DOI : 10.59161/CIPM2003REC1E