Hej Ole! On 10/4/18 11:21 AM, Ole Petter Ronningen wrote: > On Thu, Oct 4, 2018 at 11:00 AM Magnus Danielson <[email protected]> > wrote: > >> Regardless, the 53230A does a filtered frequency estimation, which is >> great for achieving high precision frequency measures quickly, but not >> good for ADEV measures, as it introduces a bias due to the lower >> bandwidth of the filtering as compared to the sampling interval. >> Dead-time gaps biases also comes in. >> > > True - but be aware that the *first sample* returned from the instrument, > when fetched using "READ", will also be biased in an absolute sense - the > frequency reported will systematically be too high or too low (the > magnitude and direction of the error depending primarily on gate time, from > what I've seen).
Who-oh! OK. This means that one should intentionally let a number of samples pass before trusting it. It would be interesting to get some better qualifications of this. > So even when using this mode to only look at high resolution "absolute > frequency measurements", it is easy to get bitten if the data is collected > using a computer. Obviously. Good to know. Many thanks! It is interesting to learn that we still need to handle the temperament of instruments. Cheers, Magnus _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
