On Jan 20, 4:46*am, Mxsmanic wrote:
How sensitive are these CSACs to other environmental variables? What about
shock, or position? Are they robust enough to be used in wris****ches and
portable timepieces (disregarding cost)?

Which reminds me: why are there no wris****ches that use GPS just for a time
reference, without the geolocation functions? Or are there? Seems like there'd
be a market for such watches to replace "radio-controlled" watches depending
on WWVB and the like, if the price isn't too high. They wouldn't need a CSAC,
although that would be a nice bonus.

This first generation chip atomic clocks are still in the US$ 1000+
price scale. That should keep it's use down to where really needed.
Probably another 20 yrs until we have a micro chip scale atomic clock.
No clarification were given in the accuracy of the equipment at its
temperature limits. It's very likely that CSAC measures its own
temperature and compensate its output with measured temperature, so
its entirely possible that its accuracy stay within specs for its
entire operating temperature envelope.

A wrist watch that can keep time down to one second per year precision
is more than good enough, except for those who want to waste money on
pricey status objects.

Current quartz frequency standards already can keep time down to 30 ms
per year (source wikipedia) ! Though its likely that accuracy is
attained by larger chip sized quartz oscillator instead of the tiny
quartz circuits found in wrist watches. Even smaller last generation
micro quartz oscillators should be able to reach one second per year
accuracy, so why would you want a GPS receiver just to set the
clock ???? Just so you don't need to ever set your watch again ?