I would agree, the point of keeping the cal data intact is the ability to tell if the unit is 'in tolerance' on arrival at Agilent, useful information about the 'quality/stability' of the meter, I think.
Also, the 'cal number' is stored in the 'cal RAM'. If you send the 3457A in with no cal data stored and it comes back with a 'cal number' of '1', I guess you also get the answer to the question of how the 'cal number' increments after a visit to Agilent. Is there a 'cal number' stored in other 34xxA DMM's? 3478A for instance? Joe -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dr. David Kirkby Sent: Tuesday, August 20, 2013 12:39 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3457A calibration? On 20 August 2013 02:59, J. L. Trantham <[email protected]> wrote: > Interesting video. A bit of a silly video IMHO. I can't take anyone seriously who measures the noise on a 6.5 digit multimeter by looking at the digits which change as it is across his standard bench power supply. Personally I would have thought one measured the stability of the bench supply by measuring with the DVM rather than the other way around > On the 3458A that I was able to 'kill' the 'cal RAM', the 'cal > counter' was at '1' when I received it. When I finished doing my 'home cal' on a 'blank' > 'cal RAM', the 'cal counter' was about 20 or so. It appears that > every measurement that is calibrated increments the 'cal counter'. I was thinking about that cal ram, and the issues changing the battery. If one intends sending the meter away for cal, is there any point in worrying about if the ram is kept alive? I guess it might be nice to know the performance before it was calibrated as Agilent will give you, but there is a bit of a risk of damaging chaning the battery live. I intend changing the battery in mine then sending it for cal. Dave _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
