Re: [volt-nuts] HP 3457A calibration?
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-boun...@febo.com [mailto:volt-nuts-boun...@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" wrote: > On 20 August 2013 14:51, J. L. Trantham 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. ___ 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.
Re: [volt-nuts] HP 3457A calibration?
On 20 August 2013 17:14, Joseph Gray 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 ___ 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.
Re: [volt-nuts] HP 3457A calibration?
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" 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" wrote: > >> On 20 August 2013 15:27, Rob Klein 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. >> >> ___ 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.
Re: [volt-nuts] HP 3457A calibration?
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" wrote: > On 20 August 2013 15:27, Rob Klein 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. > > ___ 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.
Re: [volt-nuts] HP 3457A calibration?
On 20 August 2013 15:27, Rob Klein 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.
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" wrote: > On 20 August 2013 14:51, J. L. Trantham 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.
Re: [volt-nuts] HP 3457A calibration?
Op 20-8-2013 7:39, Dr. David Kirkby schreef: 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 Not only that, the guy obviously doesn't even know how the thing works, based on his 'explanation' of integration time. Good video for when I can't get to sleep, though ___ 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.
Re: [volt-nuts] HP 3457A calibration?
On 20 August 2013 14:51, J. L. Trantham 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.
Re: [volt-nuts] HP 3457A calibration?
Joe, You might start with just measuring the battery voltage. There are two different batteries used in the 3457A, one that is obsolete and the other still obtainable. Per the manual, there are two resistors that need to be changed if switching from the 'obsolete' battery to the 'new battery'. However, I wonder if the resistors even need to be changed. See message #48954 in the archives and the several messages surrounding that. 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 -Original Message- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Joseph Gray Sent: Monday, August 19, 2013 10:16 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] HP 3457A calibration? Someone pointed out in the comments that his DMM was probably calibrated once or twice at the most. >From looking at what is on this guys shelf, he has way more money than I do to spend on test equipment. I'm jealous :-) Speaking of too much test equipment, that guy Dave who does the EEVBlog videos also has a lab to drool over. I don't know what he does for a living, but he seems to be more knowledgeable than the guy from South Africa (who is also long winded and boring). As for the "cheaper" solution, I just bought a 3457A. I expect to see it this week. After checking it out for a bit, I'll be sending it to Agilent. Although it may seem ridiculous to spend $200 getting it calibrated, I figure that I'd be better off having Agilent do it this time, so I know where I stand. I'll have to read the cal counter before and after sending it to Agilent. I'll let you know the results. If the battery looks original, I'll have to change that out before sending it for calibration. I know that I have to keep the SRAM powered, so I don't loose the data already there. Joe Gray W5JG On Mon, Aug 19, 2013 at 7:59 PM, J. L. Trantham wrote: > Interesting video. > > His 'cal certificate' shows no data other than 'in tolerance' and the > 'standards' used to established that. > > He also makes a point of the 'calibration counter'. > > 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 don't recall how many ranges the 3457A has but add them all up and > that is what I would expect the 'cal counter' to increment by once you > finish a 'home cal'. > > Since Agilent does all this via HPIB (at least that's what I think), > it increments the 'cal counter' only by '1' step. > > I would opt for a 'cheaper' 'seems to be working' 3457A then send it > to Agilent for their calibration rather than spend extra for someone > else's calibration. > > Joe > WB4BPP > > -Original Message- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] > On Behalf Of Joseph Gray > Sent: Monday, August 19, 2013 8:20 PM > To: Discussion of precise voltage measurement > Subject: [volt-nuts] HP 3457A calibration? > > Recently, we were discussing where to get a DMM calibrated. Someone > mentioned an ebay seller in Albuquerque who had their meters > calibrated across town by a company with a similar name. > > I am currently watching a YouTube video about the HP 3457A. At around > 7 minutes, take a look at the calibration certificate when he holds it up. > > http://www.youtube.com/watch?v=HfxpJCdgVwc > > Joe Gray > W5JG > ___ > 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. > > ___ 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.
Re: [volt-nuts] HP 3457A calibration?
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: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] 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 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 -- 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.
Re: [volt-nuts] HP 3457A calibration?
On 20 August 2013 02:59, J. L. Trantham 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 -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
Re: [volt-nuts] HP 3457A calibration?
Someone pointed out in the comments that his DMM was probably calibrated once or twice at the most. >From looking at what is on this guys shelf, he has way more money than I do to spend on test equipment. I'm jealous :-) Speaking of too much test equipment, that guy Dave who does the EEVBlog videos also has a lab to drool over. I don't know what he does for a living, but he seems to be more knowledgeable than the guy from South Africa (who is also long winded and boring). As for the "cheaper" solution, I just bought a 3457A. I expect to see it this week. After checking it out for a bit, I'll be sending it to Agilent. Although it may seem ridiculous to spend $200 getting it calibrated, I figure that I'd be better off having Agilent do it this time, so I know where I stand. I'll have to read the cal counter before and after sending it to Agilent. I'll let you know the results. If the battery looks original, I'll have to change that out before sending it for calibration. I know that I have to keep the SRAM powered, so I don't loose the data already there. Joe Gray W5JG On Mon, Aug 19, 2013 at 7:59 PM, J. L. Trantham wrote: > Interesting video. > > His 'cal certificate' shows no data other than 'in tolerance' and the > 'standards' used to established that. > > He also makes a point of the 'calibration counter'. > > 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 don't recall how many ranges the 3457A has but add them all up and that > is > what I would expect the 'cal counter' to increment by once you finish a > 'home cal'. > > Since Agilent does all this via HPIB (at least that's what I think), it > increments the 'cal counter' only by '1' step. > > I would opt for a 'cheaper' 'seems to be working' 3457A then send it to > Agilent for their calibration rather than spend extra for someone else's > calibration. > > Joe > WB4BPP > > -Original Message- > From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On > Behalf Of Joseph Gray > Sent: Monday, August 19, 2013 8:20 PM > To: Discussion of precise voltage measurement > Subject: [volt-nuts] HP 3457A calibration? > > Recently, we were discussing where to get a DMM calibrated. Someone > mentioned an ebay seller in Albuquerque who had their meters calibrated > across town by a company with a similar name. > > I am currently watching a YouTube video about the HP 3457A. At around 7 > minutes, take a look at the calibration certificate when he holds it up. > > http://www.youtube.com/watch?v=HfxpJCdgVwc > > Joe Gray > W5JG > ___ > 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. > > ___ 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.
Re: [volt-nuts] HP 3457A calibration?
Interesting video. His 'cal certificate' shows no data other than 'in tolerance' and the 'standards' used to established that. He also makes a point of the 'calibration counter'. 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 don't recall how many ranges the 3457A has but add them all up and that is what I would expect the 'cal counter' to increment by once you finish a 'home cal'. Since Agilent does all this via HPIB (at least that's what I think), it increments the 'cal counter' only by '1' step. I would opt for a 'cheaper' 'seems to be working' 3457A then send it to Agilent for their calibration rather than spend extra for someone else's calibration. Joe WB4BPP -Original Message----- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of Joseph Gray Sent: Monday, August 19, 2013 8:20 PM To: Discussion of precise voltage measurement Subject: [volt-nuts] HP 3457A calibration? Recently, we were discussing where to get a DMM calibrated. Someone mentioned an ebay seller in Albuquerque who had their meters calibrated across town by a company with a similar name. I am currently watching a YouTube video about the HP 3457A. At around 7 minutes, take a look at the calibration certificate when he holds it up. http://www.youtube.com/watch?v=HfxpJCdgVwc Joe Gray W5JG ___ 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.
[volt-nuts] HP 3457A calibration?
Recently, we were discussing where to get a DMM calibrated. Someone mentioned an ebay seller in Albuquerque who had their meters calibrated across town by a company with a similar name. I am currently watching a YouTube video about the HP 3457A. At around 7 minutes, take a look at the calibration certificate when he holds it up. http://www.youtube.com/watch?v=HfxpJCdgVwc Joe Gray W5JG ___ 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.
