meant to say that these: Agilent 3458A, Datron 4000A, and Datron 4708 are for sale here: http://boston.craigslist.org/bmw/ele/5687633175.html
On Tue, Jul 19, 2016 at 12:02 PM, Chris <caal...@gmail.com> wrote: > http://boston.craigslist.org/bmw/ele/5687633175.html > > > On Tue, Jul 19, 2016 at 12:00 PM, <volt-nuts-requ...@febo.com> wrote: > >> Send volt-nuts mailing list submissions to >> volt-nuts@febo.com >> >> To subscribe or unsubscribe via the World Wide Web, visit >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> or, via email, send a message with subject or body 'help' to >> volt-nuts-requ...@febo.com >> >> You can reach the person managing the list at >> volt-nuts-ow...@febo.com >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of volt-nuts digest..." >> >> >> Today's Topics: >> >> 1. Re: Keysight 3458A vs Keithley 2002 8.5 digit multimeters. >> (John Phillips) >> 2. Re: Keysight 3458A vs Keithley 2002 8.5 digit multimeters. >> (Dr. David Kirkby (Kirkby Microwave Ltd)) >> 3. Re: Keysight 3458A vs Keithley 2002 8.5 digit multimeters. >> (John Phillips) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Mon, 18 Jul 2016 09:34:18 -0700 >> From: John Phillips <john.philli...@gmail.com> >> To: il...@xdevs.com, Discussion of precise voltage measurement >> <volt-nuts@febo.com> >> Subject: Re: [volt-nuts] Keysight 3458A vs Keithley 2002 8.5 digit >> multimeters. >> Message-ID: >> < >> caneyv6bhoqhdui3m9i_abothndg3rfatfqhdgzmjope69+g...@mail.gmail.com> >> Content-Type: text/plain; charset=UTF-8 >> >> Most labs never turn 3458As off. The longer they are on the lower the >> drift >> rate. I would rather have an 20 year old meter with new batteries than a >> new meter. >> >> On Mon, Jul 18, 2016 at 4:11 AM, Illya Tsemenko <il...@xdevs.com> wrote: >> >> > Well, it's the topic many can go on and on about. >> > As with everything there are specific cons and pros of both units, but >> > here are my 5c: >> > + K2002 is smaller, lighter (4kg vs 10kg), less powerhungry (sometimes >> > it's important if you send unit for cal overseas, or take to remote >> site). >> > + K2002 can support scan cards (standard, or low-EMF ones) via expansion >> > slot >> > + K2002 DCI/ACI goes up to 2Amps >> > + K2002 goes bit higher on ACV frequency (15MHz, but performance there >> is >> > so-so) >> > + K2002 natively supports thermocouples, RTDs, SPRT thermal sensors and >> > custom settings >> > + K2002 supports rare rainbow unicorn nanovolt preamplifier Keithley >> 1801 >> > (substitute can be bodged up but that's not beginner's project) >> > - Old K2002's require capacitor replacements (units with S/N 06xxxxx and >> > 05xxxxx). Mandatory! Meters from 2005+ year have S/N starting with >> 11xxxxx >> > - Readings noisier than 3458A >> > I have two units in use, and have worklogs for both : >> > https://xdevs.com/review/kei2002/ - newer K2002 from year 2007 >> > https://xdevs.com/fix/kei2002_u2/ - older K2002 from 1994 which was >> > repaired after capacitor leak damage. >> > Service of these Keithley meters (and 2001, which are very similar >> design) >> > is not complicated, but require attention and knowledge what you doing. >> > There only few custom parts used. >> > >> > Now regarding industry standard 3458A. Reason why you saw only 3458A in >> > metrology lab is simple: >> > Superior ADC (many rightfully think it's best on market, ever), amazing >> > linearity (JJA was required to test linearity with good confidence), >> very >> > easy calibration (just need 10V reference and 10KOhm standard resistor >> to >> > get 3458A calibrated to uncertainty of used standards), Artifact >> > calibration (ACAL) to significantly remove impact of temperature >> variation >> > on accuracy, proven performance. Many labs use 3458A as main transfer >> > standard due to it's ADC performance. >> > >> > It comes at cost though, as key components of meter's A/D are custom >> > hybrids. Meaning if you got sour pill, and A/D drifting, you will have >> to >> > replace expensive A/D board. Newer Agilent/Keysight branded 3458A's are >> > essentially same boxes, just with newer hardware and likely with new >> > FPGA-based digital brains. Performance is same though, unless you really >> > getting early 1990's meter. Many design issues and items I got covered >> in >> > my repair worklog: https://xdevs.com/fix/hp3458a/ >> > >> > Brief 10V comparison : https://xdevs.com/datalog_tcomp/ - sampling 10V >> > connected to 2001+2002+3458A >> > Some of the A/D noise comparisons (meter input shorted) - >> > https://xdevs.com/article/dmm_noise/ >> > >> > So decide what fit best your needs. 3458A is overall higher performance >> > instrument, but in lot of applications outside of metrology it's >> > performance benefits may not cover up for higher price and size. Both >> 3458A >> > and 2002 are still supported and sold new by manufacturers. Regular >> > calibration of these is likely be over 1000$USD, and lab-grade >> calibration >> > for 3458A is usually in range of 2600$USD. >> > >> > P.S. there are also few other 8.5d meters, but much less information >> > available on those, as less people have them. Only "modern" 8.5d meter >> is >> > 8508A, which cost even more than 3458A without much performance >> improvement. >> > >> > 18/07/16 17:54, Dr. David Kirkby (Kirkby Microwave Ltd) пишет: >> > >> > I am interested to hear people's view on the relative merits of the >> >> HP/Agilent/ Keysight 3458A vs the Keithley 2002. >> >> >> >> I noticed that when I recently visit the standard lab for voltage at >> NPL, >> >> the place was littered with Agilent 3458As, but I did not notice a >> single >> >> Keithley 2002. But maybe NPL get better discounts from HP/Agilent >> Keysight >> >> than Keithley/Tektronix. >> >> >> >> I notice that the used prices of 3458A is higher than 2002s. >> >> >> >> Also, are there any things ons should be looking out for when buying a >> >> 3458A or 2002? I have in the past thought an Agilent front panel was a >> >> better than an HP one, as it would not be as old, but this is not >> always >> >> true - see my comment later. >> >> >> >> What S/N are best avoided? Does anyone have a record of S/Ns of >> Keighley >> >> meters with time? >> >> >> >> Very recently I had a somewhat scruffy HP 6674A PSU with a damaged >> LCD. It >> >> cost me $50 or so to pick up a clean Agilent front panel with a new >> >> display. The display actually turned out to be unsuitable, yet my >> >> Agilent >> >> badged 6674A is actually a fairly old HP unit. So white my intention >> was >> >> not to rebadge the PSU, that happened as a result of a legitimate >> reason >> >> to >> >> get it working. So this really indicates how an old HP 3457A could be >> made >> >> to look a newer Agilent one. >> >> >> >> 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. >> > >> >> >> >> -- >> >> *John Phillips* >> >> >> ------------------------------ >> >> Message: 2 >> Date: Mon, 18 Jul 2016 19:48:35 +0100 >> From: "Dr. David Kirkby (Kirkby Microwave Ltd)" >> <drkir...@kirkbymicrowave.co.uk> >> To: Discussion of precise voltage measurement <volt-nuts@febo.com> >> Subject: Re: [volt-nuts] Keysight 3458A vs Keithley 2002 8.5 digit >> multimeters. >> Message-ID: >> <CANX10hCBO9MMxwaT0E6HbumWrP+pW3= >> dkx4mq88ux2m3zkn...@mail.gmail.com> >> Content-Type: text/plain; charset=UTF-8 >> >> On 18 Jul 2016 17:34, "John Phillips" <john.philli...@gmail.com> wrote: >> > >> > Most labs never turn 3458As off. The longer they are on the lower the >> drift >> > rate. I would rather have an 20 year old meter with new batteries than a >> > new meter. >> >> If one buys a used meter, one has no idea if it has been switched on very >> occasionally or on 24/7. >> >> Do you keep your meter powered up during the transit between your lab and >> the cal lab? I would think that quite difficult if you used a courier, >> but >> not a problem if it was taken in a car. >> >> Dave. >> >> >> ------------------------------ >> >> Message: 3 >> Date: Mon, 18 Jul 2016 12:39:33 -0700 >> From: John Phillips <john.philli...@gmail.com> >> To: Discussion of precise voltage measurement <volt-nuts@febo.com> >> Subject: Re: [volt-nuts] Keysight 3458A vs Keithley 2002 8.5 digit >> multimeters. >> Message-ID: >> <CANEyv6a9Y_69qFSZnRVcEL4sKDAFsnx-PYw93= >> yproe1hww...@mail.gmail.com> >> Content-Type: text/plain; charset=UTF-8 >> >> We do not keep them powered up for transit. >> All the meter gets more stable with age. The reference gets more stable >> with burn in. >> We store 3458As energised even when we do not plan to use them for a >> while. >> Most 10 year old meters are as stable as the new meters with the high >> stability option. >> I do not have any stats but quite often we would buy an old meter that had >> a old cal sticker and find that 10 volse was still in spec. >> >> >> On Mon, Jul 18, 2016 at 11:48 AM, Dr. David Kirkby (Kirkby Microwave Ltd) >> < >> drkir...@kirkbymicrowave.co.uk> wrote: >> >> > On 18 Jul 2016 17:34, "John Phillips" <john.philli...@gmail.com> wrote: >> > > >> > > Most labs never turn 3458As off. The longer they are on the lower the >> > drift >> > > rate. I would rather have an 20 year old meter with new batteries >> than a >> > > new meter. >> > >> > If one buys a used meter, one has no idea if it has been switched on >> very >> > occasionally or on 24/7. >> > >> > Do you keep your meter powered up during the transit between your lab >> and >> > the cal lab? I would think that quite difficult if you used a courier, >> but >> > not a problem if it was taken in a car. >> > >> > 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. >> > >> >> >> >> -- >> >> *John Phillips* >> >> >> ------------------------------ >> >> Subject: Digest Footer >> >> _______________________________________________ >> volt-nuts mailing list >> volt-nuts@febo.com >> https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts >> >> ------------------------------ >> >> End of volt-nuts Digest, Vol 83, Issue 11 >> ***************************************** >> > > _______________________________________________ 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.