Hi The objective of the Avogadro Project seems to be getting to an accuracy of 0.03 ppm from a current level of ~ 10X that. The suggestion in the paper is that a quartz resonator could be monitored for change to a much tighter level than that.
Bob -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bruce Griffiths Sent: Tuesday, January 22, 2013 2:39 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] One Kg Quartz Resonator Poul-Henning Kamp wrote: > Content-Type: text/plain; charset=ISO-8859-1 > -------- > In message<7cc93b1acc5743a3b5536dbf798b7...@vectron.com>, "Bob Camp" writes: > > >> There's a paper in the February IEEE UFFC transactions proposing that the SI >> standard of mass be replaced with a 1 KG quartz resonator. >> > Has anybody ever studied if mono-isotopic quartz in the first place ? > > I pressume that would be a requirement in order to link it to the > atomic weight unit ? > > > The current intention is to accurately measure Silicon 28 single crystal spheres and use the result to refine the value for Avogadros number and thus allow a redefinition of the kilogram using Avogadros number and the mass of an atom: http://www.ptb.de/en/aktuelles/archiv/presseinfos/pi2011/pitext/pi110127.htm l Essentially one would then measure mass of such standards by counting atoms. Bruce _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.