Modern test and radio equipment have self calibration capabilities, older analog do not. Calibration is not always need for just simple test, but for specification conformation it is useful. A bit of luck also helps. In a message dated 9/17/2017 8:08:00 A.M. Eastern Daylight Time, drkirkby@kirkbymicrowave.co.uk writes: On 15 Sep 2017 10:45, "Scott McGrath" <scmcgrath@gmail.com> wrote: > > Precisely my point, But when purchasing i expect to pay for a calibration at a minimum. I have on occasions requested sellers to send an item to the manufacturer (Agilent or Keysight) for calibration *before* shipping it to me, offering to pay the calibration cost, but stating that I expect a full refund if the item fails the calibration. If a test equipment dealer is confident that something is working well, they should not object to sending it to the manufacturer for calibration, as long as the buyer is willing to pay. Of course if a seller knows little about something, they are not going to do this, but the item should be appropriately priced. One UK seller (grace1403) declined to send an Agilent N9912A FieldFox to Agilent, because "Agilent were too fussy"., failing items for trivual issues. But he did agree to send it to one of the cal labs he uses. I thought it was a waste of time going to one of the less fussy outfits, but bought it anyway. It was then clear on receipt that it was faulty. (The spectrum analyser functionality was ok, but it didn't work as a network analyzer). He took it back, but then advertised it on eBay 6 months later. When asked, he said nothing had been done to it. eBay rules about who pays the return shipping charge for an item that is "not as described' keep changing, and may be different on different sites. But on a heavy item shipped internationally, the postage cost can be comparable or exceed the calibration cost. 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.

As to the point most modern instruments have self calibration, Most of the time 'calibration' is simply the performance check adjustments are not performed unless necessary The difference being the instruments used in performance test are traceable to a national standards body. So whats referred to as calibration is in reality performance validation. How do I know this by becoming friendly with the local lab and years ago when i worked for govt i used to moonlight at one of the local cal labs. > On Sep 17, 2017, at 8:57 AM, KA2WEU--- via time-nuts <time-nuts@febo.com> wrote: > > Modern test and radio equipment have self calibration capabilities, older > analog do not. Calibration is not always need for just simple test, but > for specification conformation it is useful. A bit of luck also helps. > > > > > In a message dated 9/17/2017 8:08:00 A.M. Eastern Daylight Time, > drkirkby@kirkbymicrowave.co.uk writes: > >> On 15 Sep 2017 10:45, "Scott McGrath" <scmcgrath@gmail.com> wrote: >> >> Precisely my point, But when purchasing i expect to pay for a > calibration at a minimum. > > I have on occasions requested sellers to send an item to the manufacturer > (Agilent or Keysight) for calibration *before* shipping it to me, offering > to pay the calibration cost, but stating that I expect a full refund if the > item fails the calibration. > > If a test equipment dealer is confident that something is working well, > they should not object to sending it to the manufacturer for calibration, > as long as the buyer is willing to pay. > > Of course if a seller knows little about something, they are not going to > do this, but the item should be appropriately priced. > > One UK seller (grace1403) declined to send an Agilent N9912A FieldFox to > Agilent, because "Agilent were too fussy"., failing items for trivual > issues. But he did agree to send it to one of the cal labs he uses. I > thought it was a waste of time going to one of the less fussy outfits, > but > bought it anyway. It was then clear on receipt that it was faulty. (The > spectrum analyser functionality was ok, but it didn't work as a network > analyzer). He took it back, but then advertised it on eBay 6 months > later. When asked, he said nothing had been done to it. > > eBay rules about who pays the return shipping charge for an item that is > "not as described' keep changing, and may be different on different sites. > But on a heavy item shipped internationally, the postage cost can be > comparable or exceed the calibration cost. > > 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.

Hi, The word "calibration" is overloaded with multiple meanings, and incompatible too. "calibration" is often used to describe adjustments to make a device operate correctly, such as passing the performance checks. "calibration" in legal traceability is about measure the performance against references to form a traceable record of deviations from the norml. This may include adjustment to ease compensation, but this is not necessary. Regardless of wither adjustments where done or not, the calibration record will indicate the errors that then needs to be applied to the measurement for the measurement to be traceable, and this in itself requires documented knowledge about how to do the measurement. Otherwise it's just a fancy indication. Adjustment to a reference thus do not imply legal traceability, or even full functionality. For full functionality, you have to go through the performance check and see that all values is within limits. "calibration" can thus imply different things. I regularly see people use these terms inconsistently. That people get disappointed when they get the wrong thing is to be expected. Cheers, Magnus On 09/17/2017 05:23 PM, Scott McGrath wrote: > As to the point most modern instruments have self calibration, Most of the time 'calibration' is simply the performance check adjustments are not performed unless necessary > > The difference being the instruments used in performance test are traceable to a national standards body. > > So whats referred to as calibration is in reality performance validation. > > How do I know this by becoming friendly with the local lab and years ago when i worked for govt i used to moonlight at one of the local cal labs. > >> On Sep 17, 2017, at 8:57 AM, KA2WEU--- via time-nuts <time-nuts@febo.com> wrote: >> >> Modern test and radio equipment have self calibration capabilities, older >> analog do not. Calibration is not always need for just simple test, but >> for specification conformation it is useful. A bit of luck also helps. >> >> >> >> >> In a message dated 9/17/2017 8:08:00 A.M. Eastern Daylight Time, >> drkirkby@kirkbymicrowave.co.uk writes: >> >>> On 15 Sep 2017 10:45, "Scott McGrath" <scmcgrath@gmail.com> wrote: >>> >>> Precisely my point, But when purchasing i expect to pay for a >> calibration at a minimum. >> >> I have on occasions requested sellers to send an item to the manufacturer >> (Agilent or Keysight) for calibration *before* shipping it to me, offering >> to pay the calibration cost, but stating that I expect a full refund if the >> item fails the calibration. >> >> If a test equipment dealer is confident that something is working well, >> they should not object to sending it to the manufacturer for calibration, >> as long as the buyer is willing to pay. >> >> Of course if a seller knows little about something, they are not going to >> do this, but the item should be appropriately priced. >> >> One UK seller (grace1403) declined to send an Agilent N9912A FieldFox to >> Agilent, because "Agilent were too fussy"., failing items for trivual >> issues. But he did agree to send it to one of the cal labs he uses. I >> thought it was a waste of time going to one of the less fussy outfits, >> but >> bought it anyway. It was then clear on receipt that it was faulty. (The >> spectrum analyser functionality was ok, but it didn't work as a network >> analyzer). He took it back, but then advertised it on eBay 6 months >> later. When asked, he said nothing had been done to it. >> >> eBay rules about who pays the return shipping charge for an item that is >> "not as described' keep changing, and may be different on different sites. >> But on a heavy item shipped internationally, the postage cost can be >> comparable or exceed the calibration cost. >> >> 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. > _______________________________________________ > 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. >

Yes. An instrument with a calibration certificate is not necessarily accurate but it's inaccuracies are known and can be compensated for (but only to the accuracy of the calibration reference of course.) On 17 Sep 2017 17:39, "Magnus Danielson" <magnus@rubidium.dyndns.org> wrote: > Hi, > > The word "calibration" is overloaded with multiple meanings, and > incompatible too. > > "calibration" is often used to describe adjustments to make a device > operate correctly, such as passing the performance checks. > > "calibration" in legal traceability is about measure the performance > against references to form a traceable record of deviations from the norml. > This may include adjustment to ease compensation, but this is not > necessary. Regardless of wither adjustments where done or not, the > calibration record will indicate the errors that then needs to be applied > to the measurement for the measurement to be traceable, and this in itself > requires documented knowledge about how to do the measurement. > Otherwise it's just a fancy indication. > > Adjustment to a reference thus do not imply legal traceability, or even > full functionality. > > For full functionality, you have to go through the performance check and > see that all values is within limits. > > "calibration" can thus imply different things. > > I regularly see people use these terms inconsistently. That people get > disappointed when they get the wrong thing is to be expected. > > Cheers, > Magnus > > On 09/17/2017 05:23 PM, Scott McGrath wrote: > >> As to the point most modern instruments have self calibration, Most of >> the time 'calibration' is simply the performance check adjustments are not >> performed unless necessary >> >> The difference being the instruments used in performance test are >> traceable to a national standards body. >> >> So whats referred to as calibration is in reality performance validation. >> >> How do I know this by becoming friendly with the local lab and years ago >> when i worked for govt i used to moonlight at one of the local cal labs. >> >> On Sep 17, 2017, at 8:57 AM, KA2WEU--- via time-nuts <time-nuts@febo.com> >>> wrote: >>> >>> Modern test and radio equipment have self calibration capabilities, older >>> analog do not. Calibration is not always need for just simple test, but >>> for specification conformation it is useful. A bit of luck also helps. >>> >>> >>> >>> >>> In a message dated 9/17/2017 8:08:00 A.M. Eastern Daylight Time, >>> drkirkby@kirkbymicrowave.co.uk writes: >>> >>> On 15 Sep 2017 10:45, "Scott McGrath" <scmcgrath@gmail.com> wrote: >>>> >>>> Precisely my point, But when purchasing i expect to pay for a >>>> >>> calibration at a minimum. >>> >>> I have on occasions requested sellers to send an item to the >>> manufacturer >>> (Agilent or Keysight) for calibration *before* shipping it to me, >>> offering >>> to pay the calibration cost, but stating that I expect a full refund if >>> the >>> item fails the calibration. >>> >>> If a test equipment dealer is confident that something is working well, >>> they should not object to sending it to the manufacturer for >>> calibration, >>> as long as the buyer is willing to pay. >>> >>> Of course if a seller knows little about something, they are not going >>> to >>> do this, but the item should be appropriately priced. >>> >>> One UK seller (grace1403) declined to send an Agilent N9912A FieldFox to >>> Agilent, because "Agilent were too fussy"., failing items for trivual >>> issues. But he did agree to send it to one of the cal labs he uses. I >>> thought it was a waste of time going to one of the less fussy outfits, >>> but >>> bought it anyway. It was then clear on receipt that it was faulty. (The >>> spectrum analyser functionality was ok, but it didn't work as a network >>> analyzer). He took it back, but then advertised it on eBay 6 months >>> later. When asked, he said nothing had been done to it. >>> >>> eBay rules about who pays the return shipping charge for an item that is >>> "not as described' keep changing, and may be different on different >>> sites. >>> But on a heavy item shipped internationally, the postage cost can be >>> comparable or exceed the calibration cost. >>> >>> 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/m >>> ailman/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/m >> ailman/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/m > ailman/listinfo/time-nuts > and follow the instructions there. >