Picotest M3510A 6 1/2 digit multimeter - Page 1
Forum section: electronics / testgear

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 05, 2017, 07:46:19 am
content: Looking at the options for bench multimeters, I came across the Picotest M3510A. It's listed as a 6 1/2 digit dual screen multimeter with modern niceties like USB connectivity. It seems Keithley sells the exact same model under a different model number, the Keithley 2110, as does Array under another model. It doesn't seem to be too expensive either. Even though it's possible that these companies all use the same OEM manufacturer, they're also companies that have something to lose when it's not up to snuff.However, I'm not seeing a lot of people talking about or owning this model. What am I missing about it that turns people off?

author: supercilious
author_rank: Contributor
timestamp: November 05, 2017, 05:34:05 pm
content: I own one of these along with an Agilent branded 34401A. I can highly recommend it, and I use it way more than the Agilent. You can find my posts about this device in my posting history on this forum, and I suspect the reason people were dubious about this device was simply the Picotest brand name, but I have had no issues whatsoever. I owned a Keithley 2015THD in the past, but when I moved house, I sold it and eventually bought the Picotest and the Agilent. For what its worth, I haven't come accross any horror stories or other bad experiences other people have had with this meter.If you have any specific questions feel free to post here or message me directly.

author: nctnico
author_rank: Super Contributor
timestamp: November 05, 2017, 05:58:27 pm
content: I'd compare specs because for this price you can't buy a DMM with 6.5 digit accuracy.

author: Gyro
author_rank: Super Contributor
timestamp: November 05, 2017, 06:27:05 pm
content: Just looking at the product flyer... Basic DC accuracy (10V range) of 0.012% +/-20 digits (1yr) doesn't look so good for a 6 1/2 digit meter.I can't see any mention of input resistance either.

author: Echo88
author_rank: Frequent Contributor
timestamp: November 05, 2017, 06:34:22 pm
content: https://www.picotest.com/downloads/M3500/M3510A-MU-USER'S_MANUAL-1.04.pdfhttp://openlab.ece.illinois.edu/assets/manuals/Keithley2000Manual.pdfThe 1-year-accuracy-specs for the M3510A are all (U,I,R, didnt check the other stuff) worse than the comparable Keithley 2000.

author: Lightages
author_rank: Unknown
timestamp: November 05, 2017, 07:43:43 pm
content: Quote from: Gyro on November 05, 2017, 06:27:05 pmReally? 0.012% and, AND 20D? That is not just "not so good", that is horrible for 6 1/2 digits. That is more like a specification for 5 1/2 digits or maybe even 4 1/2. It better be cheap......

author: Gyro
author_rank: Super Contributor
timestamp: November 05, 2017, 07:59:56 pm
content: British understatementI've got a 1970's 4 1/2 digit datron that (easily) beats it.P.S. It looks as if it's only 10Meg input resistance too. There's a vague reference to configuring it in the manual but never mentioned again.

author: Echo88
author_rank: Frequent Contributor
timestamp: November 05, 2017, 08:19:13 pm
content: Would be interesting to see if it even contains a LM399 or maybe they didnt bother to do a burn in/selection.

author: Gyro
author_rank: Super Contributor
timestamp: November 05, 2017, 08:39:15 pm
content: Quote from: Mr. Scram on November 05, 2017, 07:46:19 amYes, Keithley list it as (more likely, limit it to a more realistic) 5 1/2 digit. DC Accuracy spec again 0.012% rdg + 0.002% range. 10Meg fixed input resistance.https://www.tek.com/datasheet/broad-purpose-digital-multimeters/model-2110-5-1-2-digit-dual-display-digital-multimeter

author: Kleinstein
author_rank: Super Contributor
timestamp: November 05, 2017, 08:41:02 pm
content: From the specs it looks like the best DC range is the 1 V one. It is odd to have slightly different specs on page 6 and 106, and not using the best range at the front. This would suggest it's build like many cheap 5.5 digit meters with an ADC that works with 1 or 2 V full scale and like good modern 6.5 digit meters with an ADC that covers 10-20 V.

author: nctnico
author_rank: Super Contributor
timestamp: November 05, 2017, 11:24:34 pm
content: I think this is one of the many rebadges Tektronix carries to cater for the low cost segment.

author: nukie
author_rank: Frequent Contributor
timestamp: November 05, 2017, 11:58:05 pm
content: I don't even know why Keithley sells this low end rubbish and risk tarnishing their name. Keithley for me is nano scale precision and this device is not worth the Keithley badge.Danaher surely suck the life out of the Tektronix and Keithley so bad that they have to change their name to Fortive. Now they are moving to China so very disappointing. These are two very good companies that lose their edge.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 06, 2017, 12:11:27 am
content: Quote from: nukie on November 05, 2017, 11:58:05 pmCan you explain why you feel it's rubbish? Maybe the 6 1/2 digits are optimistic, but it doesn't seem to be too bad overall.

author: nukie
author_rank: Frequent Contributor
timestamp: November 06, 2017, 12:13:44 am
content: I don't like the whole HP = Rigol fiasco, and this Keithley rebrands. They are equipment manufacturers not brand selling companies.

author: nctnico
author_rank: Super Contributor
timestamp: November 06, 2017, 12:18:49 am
content: You are a minority. They probably sell a boatload of rebadges to schools and make tons of money even with hefty discounts on inflated list prices.

author: wraper
author_rank: Unknown
timestamp: November 06, 2017, 12:52:11 am
content: Keithley is also selling M3500A as 2100. They had relatively crappy reference compared with LM399 and had a lot of noise and drift. I recall that they probably changed reference after some time but I'm not sure about it.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 06, 2017, 01:54:09 am
content: maybe modding the picotest with a better reference voltage, would do a better job and add better specs ?? sad we dont have a teardown of it.

author: trevwhite
author_rank: Frequent Contributor
timestamp: November 06, 2017, 06:23:07 am
content: I have the keithley 2110 and it's been great for my needs. I would not say I pushed it to the limits but it's very fast. Beeper is very quiet but I have been really happy with it overall. I would buy another if I needed one no question.

author: xani
author_rank: Frequent Contributor
timestamp: November 06, 2017, 06:30:14 am
content: If all you need is resolution as opposed to accuracy (as others mentioned) and long-term stability it is a great meter for a price.Dual-measure function is handy (i usually use it with theromcouple) altho on some ranges you will have some relay clicking, and it is very fast. USBTMC works out of the box in Linux and manual got a good documentation on it.That said, you could probably pick up different used 6.5 meter from ebay and get better specs. I didn't because of shipping costs to Poland ruined any savings I'd get from buying used ;/Quote from: nukie on November 05, 2017, 11:58:05 pmIt's simple, some (...let's be honestm probably a lot) buy brand first specs second.

author: rsjsouza
author_rank: Super Contributor
timestamp: November 06, 2017, 10:42:34 am
content: I can't get past the poor basic accuracy of this meter... My 1979 Keithley 191 has 1 yr 0.007% + 2d @1Gohm at the 200mV range.That and the price, which I found to be $600 new, make me think why not get the confidence of a 34461A by paying about $400 more (if in the US)?The connectivity and dual display features are nice, thus I can imagine not going even cheaper with an used 34401A.

author: xani
author_rank: Frequent Contributor
timestamp: November 06, 2017, 11:10:17 am
content: I've got mine new for ~$430 new. I'd certainly seriously reconsider if I had to pay $600 for it.