Hi Any "real" watch or clock depends very much on things averaging out. If you look at a 5 second a year watch, it might be off by a second or two a week in some weeks….
Bob On Oct 2, 2013, at 1:19 PM, Tim Shoppa <[email protected]> wrote: > You are correct, I observe that several of my circa $100 non-WWVB quartz > watches are good to 5 secs a year. > > That 5 sec a year if I do my math right... is 1.6e-7, which is only a > little worse than the spec of the ovened HP10811 (1e-7). Now under my > typical use there is a 98.6 degree F oven right next to the watch most of > the time, but I doubt that is as good as an 10811 oven :-) > > That's very impressive for a mass produced miniaturized device in such an > environment. Is there any documentation about how they achieve this? I'm > guessing there's custom-programmed temperature compensation done at the > factory for each unit, and maybe some aging before that, and maybe they > even have characterized the aging well enough that it's programmed in as a > trend as well. > > Tim. > > > On Wed, Oct 2, 2013 at 10:35 AM, Ronald Held <[email protected]> wrote: > >> Even if the spec is exaggerated, What do you expect the real world >> spec to be? Current TC watches are hard pressed to average under >> 5s/y. >> Ronald >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
