Hi Well, since we all have made our totally uninformed guesses, the only thing to do now is to give Keysight a call and see what the real answer is.
Bob > On Aug 29, 2015, at 1:46 PM, Dr. David Kirkby (Kirkby Microwave Ltd) > <drkir...@kirkbymicrowave.co.uk> wrote: > > On 29 August 2015 at 12:59, Javier Herrero <jherr...@hvsistemas.es> wrote: > >> Hello, >> >> The calibration certificate does not indicate that the measurements were >> done with the frequency counters referenced to the 5071A at the time of >> calbiration (if so, it would be listed under the Calibration Equipment Used >> table). It says that the 53132A were calibrated against the 5071A. >> >> If for your calibration they have used 53132A witout the oven oscillator >> option it is very probable that its uncertainity is 7.6ppm as indicated in >> the certificate. Since the maximum error tolerable for the LCR meter is >> 100ppm (+/-100Hz @ 1MHz), it makes sense to perform the measurement with an >> instrument with an uncertainity of 7.6ppm, and not to use the better >> counter in the lab for that purpose. >> >> Regards, >> >> Javier > > > I would find it a bit hard to believe they would use a counter without an > oven in their lab, as it would seriously restrict what they can do with it, > making it more difficult to replace one counter with another. I would have > thought that within reason it best to have the lab have reasonably high > spec kit, so more than one instrument could be done on the same line. They > did for example use a pair of 3458As, despite I'm sure the voltage accuracy > requirements could be met with a multimeter with far greater uncertainty > than an expensive 3458A. It makes more sense (within reason) to have 3458As > in the cal lab, as it allows a wider range of instruments to be calibrated. > > Also, if you consider the spec on the 53132A without an oven, it is 3 x > 10^-7 per month. So after 12 months that could be 12 * 3 10^-7 or 3.6 > 10^-6, so if it did drift the maximum amount each month for a year, the > uncertainty would higher than it actually is. > > I intended to contact Keysight about the calibration for a couple of other > reasons > > 1) I would like to know if it was adjusted or not. That is not clear from > the cal certificate, since the > > * As received condition - Not applicable, as this calibration certificate > applies to the initial calibration of a new, refurbished or upgraded > equipment. > * Action taken - The equipment was upgraded. > > I doubt it has seen a cal lab in ages. > > The upgrade was just a software one, to enable cable lengths of 2 m and 4 m > (option 006) to be used to connect the DUT, which they kindly provided free > of charge, on the condition I paid for the calibration. > > 2) They never put any stickers over the screws that prevent the covers > being removed, which struck me as a bit odd. > > Since I was going to ask about those two issues, I will ask about the > uncertainty on frequency too. It will be interesting what response I get. > I'm just interested - I realize that this instrument does not demand much > of the counter used to calibrate it. The demanding calibration devices > would be the resistance and capacitance standards. > > Dave > _______________________________________________ > 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.