); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] Hi Peter,
Do you like the way the NIST page looks now? http://tf.nist.gov/general/enc-re.htm#resonancefrequency http://tf.nist.gov/general/enc-re.htm#rubidiumoscillator /tvb >> Thank you all for your replies. It still begs the question of why >> NIST and PTB disagree by nearly 5 Hz on their web pages - I'll write >> and ask them, and report back what they say. >> >> Regards, >> >> Peter Vince (G8ZZR, London) > > Peter, > > Yes, please send a note to NIST and have them update the > Rb hyperfine frequency that appears in: > http://tf.nist.gov/general/enc-re.htm#rubidiumoscillator > > My guess is the old ...608 number came from a 1959 paper: > Hyperfine Transitions in Rubidium-87 Vapor > http://tf.nist.gov/timefreq/general/pdf/1537.pdf > > I suggest for the purposes of their glossary, the new number > doesn't have to be accurate to the micro-Hertz and probably > doesn't need to be changed every time someone does a new > experiment with Rb. > > NIST gives the defined value for Cesium: 9,192,631,770 Hz > and a rounded value for Hydrogen: 1,420,405,752 Hz, so a > value of 6,384,682,612 Hz might do. Not sure what to say > about ...612.8 vs. ...610.904. Let NIST figure that one out. > > Either way, I don't have to change my cars ;-) > http://www.leapsecond.com/pages/unix/ > > /tvb _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
