I meant to say Guard and Lo. On Sat, Aug 16, 2014 at 5:47 PM, Todd Micallef <[email protected]> wrote:
> > ...The CLIP shows nothing else in between ground and guard... > > Todd > > > On Fri, Aug 15, 2014 at 11:06 AM, Jason Watson <[email protected]> > wrote: > >> I've also seen excessive Guard to Low leakage when varistor RV501 has gone >> bad (it's located on the front/rear switch pcb and it's possible to >> replace >> it while leaving the circuit board in place if you are careful). >> HP/Agilent/Keysight Part number is 0837-0196, cross referenced to a >> Harris >> Corp. V430MA3A. >> >> >> On Fri, Aug 15, 2014 at 10:46 AM, Stephen Grady <[email protected]> >> wrote: >> >> > Randy, >> > >> > I have come across a few 3458A's that had leakage between Guard and Low >> > when >> > te guard is in external guard position. This was due to a leaky external >> > guard switch and/or leaky front rear switch. This can be quickly >> determined >> > by measuring resistance between guard and low with guard external. This >> > normally in not an issue except when you are using 3458A to measure >> voltage >> > with low above earth potential say in a bridge the guard low leakage >> will >> > be >> > loading other arm of the bridge. >> > >> > Kind Regards, >> > >> > Steve Grady >> > Sydney, Australia >> > >> > -----Original Message----- >> > From: [email protected] [mailto:[email protected]] On >> > Behalf Of Randy Evans >> > Sent: Friday, 15 August 2014 1:22 PM >> > To: [email protected] >> > Subject: [volt-nuts] New HP3458A >> > >> > I picked up a used HP3458A today, which I needed for some precision DC >> > measurements i need to make. It passes all the self tests and the Auto >> Cal >> > but is there any thing else I can check ( I have a 14 day RR). It >> reads a >> > 10V standard I made within a few tens of ppm, but it's not a 732A but >> that >> > is at least comforting. It also reads an ESI 10Kohm standard resistor >> dead >> > on. >> > >> > The only problem is that the display has some faint pixels in some >> > locations, with three in the second row for every digit location dead. >> > Likely a pixel driver I would think. >> > >> > I am not too familiar with it yet but I noticed when I push the auto >> zero >> > button, the display has a blinking square until I hit a measurement mode >> > button; e.g., DCV, ACV, OHM, etc. Is this normal? >> > >> > Regards, >> > >> > Randy Evans >> > _______________________________________________ >> > 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. >> > >> > >> > --- >> > This email is free from viruses and malware because avast! Antivirus >> > protection is active. >> > http://www.avast.com >> > >> > _______________________________________________ >> > 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. >> > > _______________________________________________ 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.
