> > Certainly. But what's your point? I don't see these utilities failing > > if a second slips here or there. The one case where time is critical > > is the power grid, and they keep their own time (Which, IIRC > > approximates UTC).
The power companies used to use GOES heavily; early this year the last of them switched to GPS as a time and phase reference. If there's a power industry person in time-nuts we'd love to ask you a few questions. > The long term average of the power grid in the US is 60.000 Hz. Short > term variations from that can and do happen. It is to make sure that > the clocks run on time, on the average. It might be better to say > that the power grid approximates the SI second, since it has no notion > of which second it is (although the control infrastructure for the > grid most likely does). > > Warner For real plots of 60 Hz mains frequency, including Allan deviation, see: http://www.leapsecond.com/pages/mains/ The tolerance is good; but so far from the level of astronomical or atomic seconds that it's not an issue. /tvb _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
