I've watched a few of his videos and they are all like that. Considering his apparent knowledge level and how boring he is, I probably won't bother with his other videos. Joe Gray W5JG On Aug 20, 2013 11:48 AM, "Dr. David Kirkby" <drkirkby@gmail.com> wrote: > On 20 August 2013 15:27, Rob Klein <rob.klein@smalldesign.nl> wrote: > > Good video for when I can't get to sleep, though .... > > Yes, it does really drag on. He could say what he has to say in 25% of > the time, by cutting out all the irrelevant rubbish. > > Dave > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > >

If you count each calibration procedure in the manual, you get 16. If you count each scale in each procedure, it is several times that. I suspect that the calnum is only incremented for each procedure. Joe Gray W5JG On Aug 20, 2013 1:10 PM, "Joseph Gray" <jgray@zianet.com> wrote: > I've watched a few of his videos and they are all like that. Considering > his apparent knowledge level and how boring he is, I probably won't bother > with his other videos. > > Joe Gray > W5JG > On Aug 20, 2013 11:48 AM, "Dr. David Kirkby" <drkirkby@gmail.com> wrote: > >> On 20 August 2013 15:27, Rob Klein <rob.klein@smalldesign.nl> wrote: >> > Good video for when I can't get to sleep, though .... >> >> Yes, it does really drag on. He could say what he has to say in 25% of >> the time, by cutting out all the irrelevant rubbish. >> >> Dave >> _______________________________________________ >> volt-nuts mailing list -- volt-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> and follow the instructions there. >> >>

On 20 August 2013 17:14, Joseph Gray <jgray@zianet.com> wrote: > I have replaced this type of battery in other equipment, so it isn't a big > deal for me. I'm sure I can do it without losing the cal data. > > Joe Gray > W5JG Given the discussion on here a week or two ago about Agilent not adjusting something if it is spec, there may be some advantage in not having the ram contents kept. That way the meter is sure to require adjustment and do wll be adjusted as close as possible. Whilst that may not suite a metrologist who wants to track drift over time, it suits me better to have it made as close as possible, ratther than just left if within spec. Dave

I've tried this on a 3458A and lost the data in the CALRAM due (I think) to trying to read the data while the chip was still 'hot' from the removal process. Two other 3458A's were successful. I've tried this on a 3478A (much more like the 3457A) and lost the data and had to recalibrate the unit. I have not sent it to Agilent for calibration to see how 'successful' my 'home cal' was. I know safe removal and replacement of the battery can be done and has been done. However, I really missed knowing the 'in tolerance' status of the 3458A. I returned it to Agilent earlier this year and it was 'in tolerance' from the calibration the previous year, so that is some consolation. The other two 3458A's, that underwent the 'successful' CALRAM replacement, were both 'in tolerance' when returned to Agilent and again were earlier this year, thus giving confidence that they are stable for a long term and likely not needing 'calibration' on a yearly basis. I recently sent two Fluke 289, 4 1/2 digit handheld, DMM's to Fluke for calibration, one with a Calibration Date of 08/07/09 and Calibration Counter of 1 and the other with a Calibration Date of 02/10/11 and Calibration Counter of 1, and both returned with 'As Found - As Left' data and no adjustments made (Fluke Z540 Cal). This gives me great confidence in the DMM's and their ability to be accurate for many years to come with little need to return them to Fluke for 'cal'. It would appear that they have been 'in tolerance' since their original calibrations some 2 to 4 years ago. >From my perspective, as a 'neophyte volt-nut', knowing the 'in tolerance' status of the DMM is very 'confidence building'. That's all I'm trying to say. Again, good luck. Joe -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of Joseph Gray Sent: Tuesday, August 20, 2013 11:15 AM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3457A calibration? I have replaced this type of battery in other equipment, so it isn't a big deal for me. I'm sure I can do it without losing the cal data. Joe Gray W5JG On Aug 20, 2013 9:43 AM, "Dr. David Kirkby" <drkirkby@gmail.com> wrote: > On 20 August 2013 14:51, J. L. Trantham <jltran@att.net> wrote: > > If the battery is 'OK', I would favor just sending it to Agilent for > > calibration, unless you can 'SAFELY' change the battery while > > preserving > the > > cal data. > > > > Good luck. > > > > Joe > > If one accepts there is some risk changing the battery while > preserving the data, one has two choices. > > 1) Do as you say and leave the battery, preserving the cal data. This > however risk the battery leaking at some time. > 2) Change the battery, losing the cal data, but virtually eliminating > the risk of leakage. > > To me at least, the path of least risk is the one to take. > > I suspect if one put a power supply in parallel with the battery with > a 10 k resistor in series, then the 10 k resistor would not drop > enough voltage to lose the ram data, but if it was accidently shorted > the current would be limited to a few hundred microamps. That's > unlikely to do any damage > > I guess for a volt nut, preserving the cal data is more important than > it is to me. Not damaging the meter is higher on my priority list. > > Dave > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.