Along those very lines, HP/Agilent/Keysight sold both calibration kits and verification kits for VNAs. We did a full calibration using the mechanical calibration kit at the start of a measuring session where you needed the absolute best accuracy your system was capable of and used the verification kit as a sanity check during the daily operation.
Steve WB0DBS > On Jun 6, 2020, at 6:21 AM, Florian Teply <[email protected]> wrote: > > Funny thing how things work out time-wise: I had a discussion yesterday > on the very topic during re-audit for ISO 9001. > > In basic terms, verification in metrology is a very slimmed down > calibration: For a calibration, you essentially check every range of > your instrument at usually five or more spots within that range in > order to determine accurracy of your instrument in each range. > For a verification, you do this only at the spot where you intend to > measure. So if you were to measure a nominal 7.2V source, you'd compare > the reading of your meter with your, say, known good 7.5V reference > instead of doing a full calibration of the meter. It doesn't tell you > anything about, say, the offset error of your meter, or how big the > deviation is at the 1000V range, it just tells you if your meter meets > requirements of the one measurement you intend to do. > > So, in order to determine whether or not your chinese voltage reference > meets its specs, you'd check your meter against, say, the > well-characterized LTZ1000A you happen to have in your lab. > > Strictly speaking, you still have to do it as carefully as you would do > a real calibration, taking all known effects into account, but it's > still much less time-consuming than a full calibration as you check only > one single point instead of all possible ranges with five points each. > > Does this help answer your questions or did I just bring up more > questions than answers? > > best regards, > Florian > > > Am Wed, 3 Jun 2020 09:58:59 +0100 > schrieb "Dr. David Kirkby" <[email protected]>: > >> I am trying to work out what the BIPM definition of verification means >> >> https://jcgm.bipm.org/vim/en/2.44.html >> >> “ provision of objective evidence that a given item fulfils specified >> requirements” >> >> Let’s assume that I wanted to verify if the voltage reference meets >> the Chinese specifications. Would consulting the 3457A manual and >> voltage reference specifications, to determine if the meter is good >> be considered verification? >> >> Or does verification only apply to an instrument? For example >> comparing the 3457A to a Fluke voltage reference? >> >> The one sentence definition in VIM leaves me wondering what the >> intension of the entry is. >> >> >> >> > > > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
