Good Deal... or No?  - Page 1
Forum section: electronics / testgear

author: FotatoPotato
author_rank: Regular Contributor
timestamp: August 31, 2018, 11:43:45 pm
content: Hey Guys,I think I just scored a pretty good deal on a Kiethly 2700 Digital Multimeter/Data Acquisition Mainframe for $540. Its used but it looks like its in great condition. Is it a good deal? or noThanks

author: JS
author_rank: Frequent Contributor
timestamp: September 01, 2018, 05:09:39 am
content: I don't know the price in market of the device, for mainframes it usually depends on installed options, for old gear they could be hard to find and the one you need more expensive than the frame...Other than that, if it has a use for you and what you paid is justified by that use, that's usually a good deal for me.JS

author: bitseeker
author_rank: Super Contributor
timestamp: September 01, 2018, 06:07:26 am
content: Prices fluctuate quite a lot and Keithley gear can often fetch high prices. Prices have been rising for several years. So, a good deal is a relative thing.I paid less for mine a couple of years ago with two multiplexer modules installed. They've been selling for $300 – 800 lately on eBay. Did yours include any modules?

author: FotatoPotato
author_rank: Regular Contributor
timestamp: September 01, 2018, 06:30:08 pm
content: No, Mine didn't come with any modules, but that's ok because I'm mainly going to be using it as a DMM and so I don't need all of the fancy features. I guess it would be nice to have the thermocouple module but its not a deal breaker for me.

author: bitseeker
author_rank: Super Contributor
timestamp: September 01, 2018, 06:38:16 pm
content: Ah, OK. Enjoy it. It's a nice DMM and has more logging memory than the similar Keithley 2000. Do note that the electrolytic capacitors are somewhat notorious for leaking. Search the forum for specific info about that.

author: FotatoPotato
author_rank: Regular Contributor
timestamp: September 02, 2018, 02:07:24 am
content: Ok, Great! I was worried that I had wasted 500$ as I have never had a nice multi-meter but it sounds like it was a good buy. I am concerned about the capacitors though . Would you mind sending me a link to the aforementioned forum posts about the caps?Thanks!

author: bitseeker
author_rank: Super Contributor
timestamp: September 02, 2018, 02:52:41 am
content: Google is your friend:https://www.google.com/search?q=keithley+2000+capacitors+site%3Aeevblog.com%2Fforum%2F

author: JS
author_rank: Frequent Contributor
timestamp: September 02, 2018, 02:53:04 am
content: Leaky caps are more common that you think then. It's pretty common practice, before turning up your new old gear to check and change the caps, any big electrolytics as the first step, all of them if possible, depending on the age. This not only applies for measurement gear, anything with a few decades should be exposed to this process before reliably use it.There's a name for it, recapping!Looks like you did get a nice deal, I'd love to have a 6 1/2 one at home...JS

author: FotatoPotato
author_rank: Regular Contributor
timestamp: September 02, 2018, 03:45:27 am
content: I am hesitant to do so because it has according to the seller "multiple sealed calibration stickers" and opening the case to change the caps would ruin that but I guess it is worth it in order not to have leaky caps

author: Terry01
author_rank: Frequent Contributor
timestamp: September 02, 2018, 04:04:01 am
content: The only Cal sticker that matters is the one that's in date and only then if you have the proper documentation to go with it. Otherwise it could be as useless as a ticket to the moon sticker they stuck on to it, don't mean a thing unless it is traceable to proper Cal company.Better to follow the guys who know better's advice and re-cap it. Should serve you well for years to come then.I don't know a lot about bench meters but i'd say from what you said you got a decent deal. Some of the guys here get whopper deals, I often wish I could get deals like that!

author: bitseeker
author_rank: Super Contributor
timestamp: September 02, 2018, 05:26:17 am
content: Quote from: FotatoPotato on September 02, 2018, 03:45:27 amIf all of the following apply, then don't open it. In general, though, it's better to have a working DMM than a dead one that's "in calibration."1. The recalibration date hasn't yet passed.2. You have the calibration certificate from the lab that calibrated it and its dates match the cal sticker.3. The work that you do is accountable for its accuracy and you must be able to prove that your measurements and the equipment used to make those measurements follow specific standards.For typical uses, regular traceable calibration is usually unnecessary. I'm part of the US Calibration Club on the forum and on the last go-round of the Geller SVR-T 10V reference we were trying out, my meters measured as shown below. Looks pretty stable to me.Bench DMMAgilent 34410A: 10.00010 (Cal 8/2009)Agilent 34401A: 10.00026 (Cal 7/2003)Keithley 2700: 10.00007 (Cal unknown)Keithley 196: 10.00035 (Cal unknown)Fluke 8100A: 10.002 (Cal unknown)Handheld DMMAgilent U1272A: 9.978 (Cal 6/2012)Keysight U1282A: 9.998 (Cal 12/2016)Keysight U1252B: 10.000 (Cal 10/2016)Greenlee DM-820A: 10.00 (Cal unknown)Note that although I don't know the exact age of my Fluke 8100A, they were made from 1969 through 1972 (based on the manuals that I have). So, if it had never been calibrated since manufacture, that's quite a long time to hold its calibration and it's pretty much bang on 10V.