Hi That was just a test to see if anybody was watching.
It should read: ... A change of one in 1,000,000,000,000... ... change of 0.001 Hz ... I'm sticking to my test story no matter what. Any contrary evidence of freshly emptied Riesling bottles rolling around the floor should be ignored. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob Camp Sent: Thursday, January 21, 2010 11:42 AM To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] LPRO Pressure Sensitivity Hi >From the ever useful Wikipedia: http://en.wikipedia.org/wiki/Parts-per_notation ppt = parts per trillion. A change of one in 1,000,000,000. Just like ppm or ppb, only smaller. In this context at 10 MHz, 10 ppt would be a change of 0.0001 Hz. Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of SAL CORNACCHIA Sent: Thursday, January 21, 2010 10:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] LPRO Pressure Sensitivity Hi Bob, Can You explain what 10 PPT stands for. Thank You ________________________________ From: Bob Camp <[email protected]> To: Discussion of precise time and frequency measurement <[email protected]> Sent: Thu, January 21, 2010 7:50:43 AM Subject: Re: [time-nuts] LPRO Pressure Sensitivity Hi Yes indeed. There really isn't a lot of data out there on pressure on rubidiums. Of course we don't talk about it a lot on our data sheets either ... If you accept that a normal day might have a 100 millibar change, That changes the frequency 10 ppt, if the guess is right. At 10X that level it would be as significant as temperature on a good unit. If it was that big it should get a lot more attention ... Bob On Jan 21, 2010, at 4:53 AM, Magnus Danielson wrote: > Bob Camp wrote: >> Hi >> Has anybody taken any data on LPRO's to see what their pressure sensitivity is? I'm guessing it's ~ 0.1 ppt / millibar. That's only a guess backed up by no data at all .... > > Do you mean 1E-13 per millibar? (I am only guessing) > > Cheers, > Magnus > > _______________________________________________ > 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. _______________________________________________ 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.
