[GreenKeys] Accurate clocks...

[brooke at pacific.net]

Hi Don:

The definition of time is based on a Cesium standard operating under
specified conditions, so in theory it's perfect, i.e. has no drift.

But practically there's a limit on how well you can adjust one so it's
rate has some error, BUT unlike a crystal oscillator that has a parabolic
time error vs. running time plot, a Cesium standard has a straight line
plot.

More info on Cesium standards:
http://www.prc68.com/I/FTS4060.shtml

Have Fun,

Brooke Clarke
http://www.prc68.com

Don Robert House wrote:
> AHH yes now I recall...  Cesium.
> That is the element that is accurate to one second over 400 years.
>
> Somewhere here in my books on synchronization I have the different
> levels and accuracy of clocks.
>
> Rubidium is almost affordable these days.
>
> As we say in the Telephony business,  Timing is Everything!
>
> Don