Second hand Keithley 2000 vs new Rigol or Siglent 6.5 digit meter - Page 1
Forum section: electronics / testgear

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: November 02, 2017, 01:13:55 pm
content: Hi guys. I'm probably going to purchase my first big-boy DMM. I'm aiming to get a 6.5 digit meter.On ebay you can find various listings of keithley 2000 meters, in various conditions. If you can live with units that are missing parts of the case and the stand because they were used in a rack, there are options as low as 200 Euros. However, I recenetly found a reseller that offered calibrated units, with a NIST-tracable certificate for a the same price as a new 6.5 digit Rigol.The fact that acording to the datasheet the Rigol is better in pretty much every way (drift and resolution, keithley is 1 mil vs Rigol's 2 milion count) and the Rigol comes with more features like LXI and such which I think would be nice for me (I like using my computer as a central control system). In addition, the 200 uA seems a nice feature of the Rigol over the Keithley.However, the Keithley has the brand name and history. And since it will be quite old already, it's likely it's real drift is far lower than the advertised datasheet drift.Any suggestions as to what to get? And what about Siglent's meters? I'm not that familiar with those.

author: nctnico
author_rank: Super Contributor
timestamp: November 02, 2017, 08:51:23 pm
content: I'd go for one from Keysight like the 34461A. The price difference isn't that much to justify mucking about with the B-brands.

author: tautech
author_rank: Super Contributor
timestamp: November 02, 2017, 09:05:43 pm
content: There's a thread that covers all 3 Siglent bench DMM's:https://www.eevblog.com/forum/testgear/siglent-new-bench-dmm-sdm3055/The 6.5 digit SDM3065X can also have a 16ch logging card option fitted but it must be installed at the factory.Can't be retrofitted as there's a bunch of HW that needs installing.The internal reference is the good old LM399H.The UI is almost identical between the 3 models.Member Defpom had a look at my demo unit here:

author: dr.diesel
author_rank: Super Contributor
timestamp: November 02, 2017, 09:08:55 pm
content: Quote from: nctnico on November 02, 2017, 08:51:23 pmThis is also what I'd do.

author: tautech
author_rank: Super Contributor
timestamp: November 02, 2017, 09:31:47 pm
content: Quote from: dr.diesel on November 02, 2017, 09:08:55 pmLittle in the way ofhelpfulcontent from the #1&2 Siglent haters on this forum.

author: nctnico
author_rank: Super Contributor
timestamp: November 03, 2017, 12:03:12 am
content: Who's is writing about Siglent? I wouldn't buy the Rigol either. Keithley, Fluke & Keysight have decades of experience with these kind of high precision meters which IMHO is worth spending the relatively small amount of extra money on.

author: wraper
author_rank: Unknown
timestamp: November 03, 2017, 12:27:19 am
content: After dealing with Rigol warranty service in EU for DM3068, I would ever buy Rigol only if I have extremely good deal. Build quality is pretty much playing in lottery. My meter had a few reworked ICs in sensitive area with guard gaps all around. They left all of the flux residues on PCB and soldered a few bodge wires in parallel to already existing traces. Replacement with the same PCB revision had none of that crap, including bodges. BTW, about that wonderful replacement meter which I got instead of my 2 weeks old meter (when it was sent 1st time). I got it after sending my meter IIRC 4th time, and Rigol stubbornly not admitting an obvious fault with AC voltage and current measurment. It was showing a jumpy crap which was accurate as $5 Chinese multimeter and Rigol was claiming it's supposed to be within spec. Final time I tired from this footballing and destroyed one part on the PCB so it did not measure AC at all, therefore Rigol could not claim such BS again. Replacement was well used unit with visible dirt and PCB scrotched in one spot and therefore one SMT pad falling off (they replaced exploded TVS),Rigol. Not to say each travel to Rigol took more than a month. My guess is those bodge wires might have been related to jumping crap they probably "fixed" at factory and then it appeared again after a little while.PCB photohttps://plus.google.com/photos/117212633093763827202/album/5861950419366571361/5861950731784117778

author: ruairi
author_rank: Frequent Contributor
timestamp: November 03, 2017, 12:37:28 am
content: QuoteSays the Siglent shill on the forumI haven't used any of the Rigol or Siglent multimeters so I have no opinions there but I did own a Keithley 2000 for a while and had it alongside my Keysight 34465a, a HP 34401a and a 34411a. If buying used I would definitely prefer a 34401a to the Keithley 2000, from a UI point of view.

author: wraper
author_rank: Unknown
timestamp: November 03, 2017, 12:57:14 am
content: Dunno about how well Siglent works but front panel and interface is a shameless knockoff of Keysight 3446x.

author: fonograph
author_rank: Frequent Contributor
timestamp: November 03, 2017, 02:26:25 am
content: I dont understand why would anyone buy chinese dmm over keysight 34461,the price difference is so low and while keysight have excellent customer support and track record,the chinese instruments are exact opposite with buggy software,russian roulette hardware and specs you cant thrust.I am not saying everything from China is bad,the siglent spectrum analyser seems good for money for example,but I would never buy it if there was keysight equivalent that cost close enough.With the 34461 costing so close,the chinese price advantage is practicaly gone so in my eyes there is no reason to buy it,even if it was 400€,I rather buy used 34401 on ebay.

author: MarkF
author_rank: Super Contributor
timestamp: November 03, 2017, 02:43:42 am
content: The Signal Path did reviews on the Rigol DM3068 6.5 Digit Digital Multimeterand the Siglent SDM3055A (SDM3055) 5.5-Digit Multimeter

author: EEVblog
author_rank: Unknown
timestamp: November 03, 2017, 06:16:29 am
content: Quote from: ruairi on November 03, 2017, 12:37:28 amOh, Burn!QuoteThere is also the fact that Siglent directly ripped off the Keysight UI, right down to every menu option, displays, and buttons.I can imagine people might boycott Siglent based on that fact alone.As for which 6.5 digit to go for, the Siglent is $730 vs $940 for the Keysight 34460ANot that big a difference at that sort of price end, so I'd have to recommend erring on the side of the Keysight as a matter of course here.Anyway, someone posted a Keithley 2015 for $250 in another thread, a bargain.

author: saturnin
author_rank: Regular Contributor
timestamp: November 03, 2017, 07:03:11 am
content: From DM3068 Service Guide (http://gotroot.ca/rigol/service%20manuals/DM3068_ServiceGuide_EN.pdf):To Obtain Calibration Service: As the DM3068 does not support user calibration, pleasesend your meter back to usfor professional calibration when necessary.Why on earth should I send the meter back to the manufacturer if I have an independent cal lab in my town??I went through some teardown images of DM3068. Are they serious they placed the main reference (LM399) next to the fan ?? (Yes, the reference is partially shielded by the metal shield, but there is a hole in it just by the reference)From TI's aplication report (http://www.ti.com/lit/an/snoa589c/snoa589c.pdf):Mounting is an important consideration for optimum performance. Although the thermal shield minimizes the heat flow, the LM199 should not be exposed to a direct air flow such as from a cooling fan. This can cause as much as a 100% increase in power dissipation degrading the thermal regulation and increasing the drift. Normal conviction currents do not degrade performance.My advice: if you want to trust your DMM, buy it from a reputable company that knows how to design precision equipment. It pays off...

author: MrW0lf
author_rank: Frequent Contributor
timestamp: November 03, 2017, 09:05:50 am
content: Desktop DMM is much more than just a box displaying single number. I plan to get 6.5 digit one next year and been reading specs a little. It is a long read. For example pay attention to sampling rate and memory (storage) amount if plan to log stuff. Also may want to think is it going to be direct use or integrated system via PC. Is there need for extra connectors on the back etc?As for A and B brands - Keysight did manage produce handheld DMM that was not up to the task so everyone may f*** upBut of course, Rigol in separate class far beyond measure

author: Rbastler
author_rank: Frequent Contributor
timestamp: November 03, 2017, 09:31:24 am
content: Id go for the Keysight 34460A. Just because of the software support.I had no issue regarding the LM399 getting to much airflow in the DM3068. I checked it at the universities cal lab and there was no problem. But still, the PC software sucks. When I bought the DM3068 I wanted LXI lan and the lan option on the keysight was 100€ more, so it price roughly woud've been 1k€ but now I regret buying the DM3068 somewhat. Its a nice instrument, but the PC software is horrible. I have to use matlab.And it sucks that I cant adjust the DM3068 myself.

author: Dubbie
author_rank: Unknown
timestamp: November 03, 2017, 09:46:33 am
content: I went with the Keysight. No regrets. I have nothing at all against Chinese instruments, but in this case you can effectively get the Tesla for only a few dollars more than the Great Wall. The Chinese version is almost certainly adequate for what I require, but the big name brand is psychologically nicer to own.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: November 03, 2017, 12:11:25 pm
content: So I see a lot of people saying I should go with the Keysight. Problem is that at that point we are talking double the price of a second hand Keithley 2000, and to be honest the keysight is just too far out of my budget. I think I' m going to go for the keithley 2000 then. Thanks for the feedback.

author: EEVblog
author_rank: Unknown
timestamp: November 03, 2017, 02:20:30 pm
content: If you can get the Keithley cheap it will serve you well.