[time-nuts] One Kg Quartz Resonator

[Bob Camp]

Hi

If you take the position that a primary standard is only functional if it's
under the ideal nominal conditions - you have no primary standards at all.
They all require corrections of one sort or the other. Having a system with
no standards is not a system at all...

The practical approach is to define the ideal conditions in a way that you
can indeed correct back to them. The most common way is to take the
contribution to zero. There obviously are other approaches. Regardless of
weather you take it to zero or x.xxx the net result is the same, as long as
everybody does the same thing. 

Bob

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Chuck Harris
Sent: Thursday, January 24, 2013 12:56 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] One Kg Quartz Resonator

Hi,

It would seem to me that since the second is(was) defined
relative to a specific number of resonances of a C-beam at a
specific gravity, and inertial frame of reference, that any
deviation from the defined value is an indication of not
the error in your C-beam, but rather the error due to your
location.

Perhaps the corrections are inappropriate?

-Chuck Harris

Bob Camp wrote:
> Hi
>
> I think a better analogy would be:
>
> There don't have to be exactly X atoms in the Avogadro ball for it to be a
> standard. You simply have to know how many relative to X in order to
correct
> for your gizmo. The gotcha obviously is you need the count of each
isotope.
>
> The same sort of issue applies to a cesium. You actually measure gravity
> (and several other things) and correct for them. If there was no way to
> measure your local gravity (or magnetic field), you would have a lot of
> trouble using Cs as a primary standard.
>
> That said, the currently accepted primary mass standard is simply an
> arbitrary lump of metal. It does not connect to anything other than it's
> self. That's not a good thing at all.
>
> Bob
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