Absolute maximum voltage ratings for 34461A - Page 1
Forum section: electronics / general

author: balage
author_rank: Regular Contributor
timestamp: May 10, 2019, 07:26:29 pm
content: Hi All,I am trying to calibrate my SMU that can source up to 1100 volts. One of the specification verification steps is to measure the 1000Volt output of the instrument.My question is that how many volts can I measure with a 34461A DMM without damaging it? This sourced voltage of course can be higher (up to 1100V). Can a 1000 ranged DMM even show more that 1000 volts on its display? I don't think so...The manual mentions the Keithley 193A DMM to measure this voltage, but this also has a 1000V range.Thanks,

author: kg4arn
author_rank: Unknown
timestamp: May 10, 2019, 08:56:17 pm
content: Page 16 I thinkhttps://literature.cdn.keysight.com/litweb/pdf/34460-90901.pdf

author: Andreas
author_rank: Super Contributor
timestamp: May 10, 2019, 09:46:46 pm
content: Hello,Quote from: balage on May 10, 2019, 07:26:29 pmThe maximum rating depends on serial number:http://literature.cdn.keysight.com/litweb/pdf/34465A-01.pdfBesides that the instruments have 20% overrange for display (except for 1000V / 750V AC)https://literature.cdn.keysight.com/litweb/pdf/5991-1983EN.pdfwith best regardsAndreas

author: guenthert
author_rank: Frequent Contributor
timestamp: May 11, 2019, 03:27:41 am
content: Quote from: balage on May 10, 2019, 07:26:29 pmAt least for the HP 3456A I can assure you that it can show more (even more than the usual 20% over-range). Now it's clearly not recommended to apply a voltage exceeding the max. specified one (doh!) and for well aged equipment you're leaving safe territory even at lower voltages as component age and dust and other contamination build up.You probably want to build/get a precision high voltage divider, if you absolutely must go that high (why? surely you can calibrate at lower voltage and live with increased uncertainty at the high end, no?).

author: TheSteve
author_rank: Unknown
timestamp: May 11, 2019, 03:43:17 am
content: Quote from: Andreas on May 10, 2019, 09:46:46 pmThe service note that limited the max voltage has been superseded by this one:http://literature.cdn.keysight.com/litweb/pdf/34461A-04A.pdfAll of the 3446X/34470A series are rated to 1000 VDC/750 VAC

author: Jester
author_rank: Frequent Contributor
timestamp: May 11, 2019, 12:20:38 pm
content: FWIWI was testing the transformer excitation curve of a C.T. many years ago. I was using a Fluke rated for 1000V, and figured there must be some headroom, I was barely over 1000V, and I heard a faint click and that was it, lights out for that meter. I think I was perhaps 20V over.

author: balage
author_rank: Regular Contributor
timestamp: May 11, 2019, 08:36:01 pm
content: Thank you very much guys for your answers. Yes, I have forgotten about the operator's manual that has much more info than a datasheet.Quote from: guenthert on May 11, 2019, 03:27:41 amYes, I will build a divider to measure that voltages. Especially I need to troubleshhot the resonant converter that produces 1200 V.Quote from: Jester on May 11, 2019, 12:20:38 pmI don't want the get magic smoke out of my DMM.However I was about to measure 1000 Volts, but I decided to ask before...

author: balage
author_rank: Regular Contributor
timestamp: May 14, 2019, 11:20:57 am
content: I have found this high voltage passive scope probe:https://hu.farnell.com/staubli/68-9559-23/test-probe-set-isoprobe-iii-100/dp/2581722In a CAT I environment more than 3kV can be connected to it.

author: wraper
author_rank: Unknown
timestamp: May 14, 2019, 11:32:32 am
content: Quote from: Andreas on May 10, 2019, 09:46:46 pmNo it does not. All of it was false alarm and no further changes were made. That service note is outdated.http://literature.cdn.keysight.com/litweb/pdf/34465A-01A.pdf