Agilent 34410A question - Page 1
Forum section: electronics / testgear

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: August 22, 2019, 03:16:48 pm
content: Hello!I have purchased from eBay 34410A multimeter and i have some concerns.Why as i connect probe's on the input and instrument is on DCV range i hear relay inside clicking like crazy. This happens sometimes and for a while. Also in resistance mode relay clicks from time to time and than stops. The important thing to mention is that only happens when instrument is in AUTO Range mode. Othervise the instrument working fine.Any 34410A users here? Please help me with advice.Thank you in advance!Regards,Hrvoje

author: Zucca
author_rank: Unknown
timestamp: August 22, 2019, 03:43:23 pm
content: Self test?Next time post in Repair section

author: Nx-1997
author_rank: Regular Contributor
timestamp: August 22, 2019, 04:07:26 pm
content: Press and hold the shift button and then turn the meter on (keep holding the shift key), when you hear a beep then let go of the shift button, this will initiate a self-test. Mine don't do what you just described I think.

author: guenthert
author_rank: Frequent Contributor
timestamp: August 22, 2019, 04:24:02 pm
content: > The important thing to mention is that only happens when instrument is in AUTO Range mode.Well, then I'd think it's changing ranges.If the instrument was in Volt measurement mode and high impedance was selected and no input connected, then the measure voltage will creep (typically to either end of the range), due to the (small) input bias current charging a capacity at the input. Sooner or later it will exceed the 10V range, switch to the next range (100V), for which the instrument cannot provide high impedance input, the capacity discharges across the 10MOhm input resistance, til the meter switches to the 10V range ...

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: August 22, 2019, 04:39:26 pm
content: Quote from: zucca on August 22, 2019, 03:43:23 pmHi!Self test passed OK.Sorry but i post it here and i did click remove post but obviously it didn't deleted it. My mistake.

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: August 22, 2019, 05:12:23 pm
content: Hi again!You people wouldn't believe what was the cause of instrument's strange behaviour.The mains socket where i have plug it in is without earth line!So i connected it in normal socket and there are no issues!Thank you for your help guys anyway and sorry again if i posted in wrong section.

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: August 22, 2019, 05:14:49 pm
content: Quote from: Nx-1997 on August 22, 2019, 04:07:26 pmWrong, pressing SHIFT during power on initialize keypad test.Btw, i solved the problem.Regards,Hrvoje

author: Nx-1997
author_rank: Regular Contributor
timestamp: August 22, 2019, 05:35:45 pm
content: Sorry, I was thinking about the 34401a. My instructions for self test are correct for 34401a. You can hear a bunch of relays clicking.

author: Hrvoje_CRO
author_rank: Regular Contributor
timestamp: August 22, 2019, 06:02:17 pm
content: Quote from: Nx-1997 on August 22, 2019, 05:35:45 pmYou don't have to apologizeWe all do mistakes, i did them twice today.

author: Zucca
author_rank: Unknown
timestamp: August 23, 2019, 10:10:55 am
content: Quote from: Hrvoje_CRO on August 22, 2019, 05:12:23 pmGood for you, I don't know why but I am happy you solved the problem.Please continue to post your future findings.