OK, and then what about measurements beyond 1000 sec (for the same DUT's ADEV in the 1E-13's) taken with a 500pS counter and a 50pS counter? Nice to hear that there is exactly no difference, just use average...
On Thu, Oct 4, 2012 at 2:34 PM, Adrian <rfn...@arcor.de> wrote: > Azelio, > > as an example, with a 53131A you have an output 'granularity' of +/- 500 > ps. > No matter how much averaging happens inside the counter, if the least > significant digit is 500 ps, then the (ADEV) measurement limit is always > 5E-10 at 1 sec as I posted in the initial post to this thread. This is not > the accuracy of the counter, it's simply the available display and output > string resolution. > At 10 sec., the ADEV limit of the same counter is 5E-11 etc. etc. finally > getting limited by the reference source and other effects. > If the DUT's ADEV is in the 1E-13's, any measurement values below 1000 > sec. are void and represent just the measurement limit of the +/- 500ps > counter. > > Now I'm waiting to receive 'glasses' for my 53131A that are in transit :) > > Adrian > > > Azelio Boriani schrieb: > >> Taking 10 samples from a 1nS counter leads you to a 100pS resolution but >> the noise at best (if it is really random) is reduced by SQRT(10). So, as >> already pointed out here, there is no real substitute for lower noise, >> higher resolution measurements. >> >> On Thu, Oct 4, 2012 at 3:01 AM, Bob Camp <li...@rtty.us> wrote: >> >> Hi >>> >>> A 1 ns resolution TI counter will do the measuring part just fine. >>> Hitting >>> the number, is where it gets a bit crazy. A *good* GPSDO might get near >>> that. >>> >>> Bob >>> >>> On Oct 3, 2012, at 8:56 PM, Kevin Rosenberg <ke...@rosenberg.net> wrote: >>> >>> On Oct 3, 2012, at 6:52 PM, Kevin Rosenberg <ke...@rosenberg.net> >>>> wrote: >>>> >>>>> Nice plot! Yes, I'd have trouble measuring 10E-14 at 10E5 seconds. >>>>> >>>> Sorry, 1E-14 at 1E5. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@febo.com >>>> To unsubscribe, go to >>>> >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> >>>> and follow the instructions there. >>>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.