); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] From: "Tom Van Baak" <[EMAIL PROTECTED]> Subject: Re: [time-nuts] Cs stability Date: Tue, 17 Jul 2007 00:40:49 -0700 Message-ID: <[EMAIL PROTECTED]>
> ); SAEximRunCond expanded to false > Errors-To: [EMAIL PROTECTED] > > > In the article "OBSERVATIONS ON STABILITY MEASUREMENTS > > OF COMMERCIAL ATOMIC CLOCKS", Pekka Eskelinen claims to > > have measured a phase temperature coefficient of 100ns/degree > > for commercial Cs clocks in 1999. > > Something is wrong with that claim. There's no way a modern > cesium standard exhibits a phase shift of 100 ns for a one > degree change in ambient temperature. I have Cs standards > that often change in temperature by several degrees and still > keep to nanoseconds. I guess I need to decode that paper > and see what's wrong. I think the paper lacks a number of necessary details in order to fully understand the conditions under which this exercise took place. There is no clear list of equipment used. It can be implied that it is 5071A being used. What Time Interval counters where used is for instance not known. He have compared PPS outputs between GPS receivers (which model are those?) and Cesium. I'd like to see some investigations into how stable the GPSes and measurement equipment is to temperature. In the end, there are a few pages of material missing in there for it to give a fairly comprehensive picture. Many of these issues could probably be cleared up after some discussions with the author, but we should not have to rely on side- channels like that. It's an interesting article, but it leaves me with a few questionsmarks. It is a bit unsatisfying. > Does anyone have contact with the authors (Finland)? Should not be too hard as his email adderess is at the top of the first page. Cheers, Magnus _______________________________________________ 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.
