[time-nuts] One Kg Quartz Resonator

[Bruce Griffiths]

But can the number and type of atoms in such a standard be counted?
Otherwise its not a primary standard.

Bruce

Bob Camp wrote:
> 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-bounces at febo.com [mailto:time-nuts-bounces at 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<7CC93B1ACC5743A3B5536DBF798B7016 at 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 at 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 at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>