6.5 digit datalogging multimeter, opinions? - Page 1
Forum section: electronics / testgear

author: bronson
author_rank: Regular Contributor
timestamp: September 12, 2013, 03:00:14 am
content: Thought dump here... I need a multimeter to record tight voltage and resistance readings (load cell wheatstone bridges) and I'm looking for opinions on usability and maybe where to find it.My requirements: high hundreds of readings per second at highish digits. High tens of readings/sec is probably ok but more is definitely better. 6.5 digits should be fine, 5.5 is marginal, and my 4.5 digit Fluke is nowhere close. I'm going to configure & process the data on a Linux computer in realtime so pretty sure I need USB or LAN (unless the deal is so smokin' that a $150 GPIB interface is worth it). Flash drive won't do it.I think these are the two finalists, with street prices:Rigol DM3068 $800 (cheeeap but should do the job)Agilent 34461a $1100 (awfully new)I'm leaning toward the Rigol because I'm spending my own money... Is the Agilent worth another 30%? In the past Agilent would nickel and dime me all to heck when trying to connect to a computer, will that happen here?Been scanning ebay and SF Bay Area shops for used deals, no wins yet. Getting frustrated enough to just to bite the bullet and go new. How novel!Others that I'm pretty sure would work...Keithley 2001 $4380 (7.5 digits, lust)Agilent 34460a $945 (slow, no temp, no usb/lan?)Agilent 34410a $1346Agilent 34411a $2150Agilent 34970a $1600 (not a great multimeter, no usb or lan, $$$$ for options)Fluke 8846a $1600Keithley 2002 $5800 (8.5 digits amazing, will have one day. one day...)Keithley 2000 $1100Fluke 8845a $1000Is there anything obvious I'm missing? Anywhere to find a decent used one other than ebay? Thanks for any opinions!- Scott

author: Unknown
author_rank: Unknown
timestamp: September 12, 2013, 03:28:53 am
content: Note that reading rates are usually stated for DCV, and may be lower for resistance, especially high resistance values. A used HP 3457A should do the job, and even with GPIB adapter should be well under $800. Around $200 should definitely be possible in the SF Bay area.I haven't used either of those meters. One thing I would check in advance is the programming documentation: in the past I wasn't impressed by Rigol documentation. If I remember correctly the DM3068 programming manual is a somewhat annoying mess of commands unique to the Rigol and commands compatible with the various Agilent DMMs separated into chapters for some reason. I would check for both if they use standard protocols over USB/LAN (eg. USBTMC or LXI) and whether these are supported with decent performance under Linux. I remember early USBTMC implementations in Rigol scopes to be somewhat nasty. Rigol software will suck, but you're not going to use anyhow it if you're running Linux.This threadmay be somewhat relevant for you: don't trust the DM3068 volatile memory spec and someone's complaining about the LAN interface.

author: orin
author_rank: Frequent Contributor
timestamp: September 12, 2013, 03:34:10 am
content: Quote from: bronson on September 12, 2013, 03:00:14 amAll you need is the base 34461A to connect to a computer. Unless you are replacing a 34401A, I see no real reason to use GPIB with it. I access my '61A across a wireless link to a laptop which has its wireless and hardwired network adapters bridged. The '61A is connected to the laptop via an ethernet switch (the switch is there so I can also connect to my Prologix ethernet adapter for GPIB devices).The '61A even has a web interface to connect to it, but it does use java to to actually do anything. I don't know where they download the java code from and running a network capture to find out is one of my least favorite activities.Agilent have free capture software, but its for Windows. I tried it briefly, but it's kind of basic.FWIW, I attached a screen capture from the web interface of the 34461A monitoring my Fluke 731B. Wish I knew what caused that glitch... The drift is mostly due to the tempco of the 34461A.Orin.

author: bronson
author_rank: Regular Contributor
timestamp: September 12, 2013, 05:39:38 am
content: That's really funny that the 34461 uses a Java client. Just when I thought client-side Java was finally dead... Hope they don't rewrite it to use Flash.It's great to hear the '61 comes ready for the network. It only took HP two decades to realize almost all offices are wired for 10baseT, grr. So, yes, your reassurances probably bump the '61 over the Rigol.alm, the 3457A is a great suggestion. Dang that's one ugly multimeter, and kinda slow too. But, 6.5 digits for a few hundred bucks? I can try it and not worry too much if it doesn't work out. Definitely a finalist, even with a GPIB<->USB interface and having to mess withhttp://dawm.sourceforge.net/Now to find one...

author: grenert
author_rank: Frequent Contributor
timestamp: September 12, 2013, 06:22:01 am
content: HP 34401A, cheap and local:sfbay.craigslist.org/eby/eld/3988747551.html

author: Unknown
author_rank: Unknown
timestamp: September 12, 2013, 07:04:09 am
content: Quote from: bronson on September 12, 2013, 05:39:38 amYep, the display sucks. It's actually one of the fastest meters from that era (tens of readings/s in 6.5 digit mode and hundreds in 5.5 digit mode), but technology has advanced since then. The 34401A is (slightly) slower, for example. Still, I think it (or a used 34401A which is more expensive but supports RS-232) is probably the cheapest solution that satisfies your requirements. For the 34401A, check the maximum baud rate. In ASCII format a few hundred 5.5 digit readings might actually qualify as high bandwidth in RS-232 terms. Certainly more than a 9600 baud connection can handle. Both Dave and Martin did videos about the 3457a by the way. Dave did a teardown, Martin a review/trying to figure out how this thing works.Quote from: bronson on September 12, 2013, 05:39:38 amInterfacing should be no harder than any other meter: you have a wire-level protocol provided by a library/driver (eg. the USB GPIB interface, USBTMC, LXI) over which you send plain text (I forgot if the 3457A supports SCPI, but they will be documented in the manual) commands. In the case of an USB GPIB adapter you would use the linux-gpib library (or interfaces on top of it) for 'real' GPIB interfaces and a serial port interface for Progolix interfaces. For USBTMC you might use the kernel usbtmc driver with whatever userland interface is available. Is there some turn-key solution for the Agilent or Rigol meters that works under Linux? Scraping a web interface isn't any nicer or easier.

author: HKJ
author_rank: Super Contributor
timestamp: September 12, 2013, 09:01:30 am
content: I would stay away from Rigol, it does not support a socket connection, where you can directly send commands. I do not want any driver for a LAN connection, I want a direct socket connection, this makes it independent of OS and OS upgrades.I have been using the Fluke 8846A with LAN connection for some time and it works great and was easy to interface to.

author: bronson
author_rank: Regular Contributor
timestamp: September 12, 2013, 09:33:23 am
content: Dave's teardown was good and the discussion thread was great. Other than some very obsolete parts the 3457a looks fairly serviceable. On the other hand, I sat thru 20 minutes of Martin's before giving up. Does information density get better later on?As for connectivity, Agilent are really finding their way into my heart.http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=1189304&nid=-34952.0.00&id=1189304The '61 has LXI, the '60 doesn't. That page convinces me that I can connect to the '61 using all sorts of interfaces. The code looks a little copy-n-pastey but that sure beats calling into big, brittle libraries. At first glance it looks great.As for the Rigol, they hide their programming guide behind an email collecting page and supply it in a .chm file. SCPI doesn't look real pleasant and their code examples are really overwrought -- they seem targeted at people writing full GUIs, not at people who want to grab a quick sequence of bytes. So, workable, yes, but will take a lot of effort. (just confirmed by HKJ, nice)grenert, that stupid thing has been listed for months. I've called the guy twice, both times he claimed it's sold / not available and that the ad should be taken down then, bam, he relists it again. No idea. It sure doesn't seem to be selling. Maybe it's a bait and switch tool?

author: Unknown
author_rank: Unknown
timestamp: September 12, 2013, 09:53:57 am
content: Quote from: bronson on September 12, 2013, 09:33:23 amApart from the battery that you should probably replace after buying one (voltage is not a reliable indicator of remaining capacity for these batteries), I don't see any issue with obsolete parts. It will still be more serviceable than the current Agilent and Rigol DMMs with their custom parts and lack of schematics / good service documentation.Quote from: bronson on September 12, 2013, 09:33:23 amNot really, hence my comment about it being about him figuring out how the thing works. I remember cringing a few times when watching the video. It shows the meter in action though, unlike Dave who I think only took it apart.My impression (not owning any Rigol equipment) is also that it will probably much more painless with the Agilent meter than the Rigol. The chance of running into weird issues like the meter getting confused after a certain sequence of commands, LAN connections being unreliable or the meter not living up to its specs is much higher with Rigol than with Agilent in my opinion.

author: bingo600
author_rank: Super Contributor
timestamp: September 12, 2013, 11:41:42 am
content: I got a 3457A with Opt-44491A (8 Chan relay board) , got it from*Bay this spring for $260.The 44491A , is a neat thing , as you can switch between 4-wire ohm and Volt without physical intervention.... Can you do that wo. the Mux ? , i mean connect all 4 wires , and then just select DC (use the two) and select 4-wire and use all 4 ?It might work .. My meter is out for Cal , so i can't test.There is also a 44492A opt (10 x reed relay) , see *Bay #221280900890 , but 420$ & "as is"I'm using linux-gpib with an Agilent USB-Adapter from *Bay , and toying around with the linux-gpib python bindings.AlfBas (user here) has the same meter with Mux , and afaik. he's made some Windows prog. to do the Mux readings./Bingo

author: Rigby
author_rank: Super Contributor
timestamp: September 12, 2013, 01:10:17 pm
content: Quote from: bronson on September 12, 2013, 05:39:38 amJava clients aren't what's bad, it's the in-browser Java stuff that's terrible. Still, for cross-platform, client-side apps, .NET is probably the better solution, even for Linux and Mac.I'm not trying to start a war, here. I have years of experience with Java and .NET, professional enterprise-level experience, and this is just my opinion.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 12, 2013, 01:33:22 pm
content: Quote from: Rigby on September 12, 2013, 01:10:17 pmNot starting a fight, just asking.Aare you referring to Mono the third party partial port of .net?I have read only bad about it, are you endorsing it?

author: Tepe
author_rank: Frequent Contributor
timestamp: September 12, 2013, 02:21:20 pm
content: Quote from: bingo600 on September 12, 2013, 11:41:42 amWhere are you getting it calibrated? I have a 3457A I have been wanting to get calibrated.

author: saturation
author_rank: Super Contributor
timestamp: September 12, 2013, 02:30:15 pm
content: If you are in the USA, why buy when you can rent a 6.5 digit for $150/mo, If you've a good credit rating and if your project is of short duration to make it cost effective.Just example:http://www.us-instrument.com/commerce/catalog/product.jsp?product_id=1426&czuid=1378996024896Note, depending on who the renter is, quote rates between $90-150, be sure to include S&H and shipping insurance. 7.5 digit about $300, 8.5 digit about $500/mo.

author: Rigby
author_rank: Super Contributor
timestamp: September 12, 2013, 03:50:13 pm
content: Quote from: WarSim on September 12, 2013, 01:33:22 pmMono. For what I've used it for, it's been excellent. It doesn't include WPF or WWF (I think) but everything else is there. Lately I've been working on an app that ties a LeapMotion controller to an AR Drone 2.0 quadcopter, allowing you to fly the copter with only gestures. I just ran it on a Linux box with Mono a moment ago and it works identically to the Windows version. I had to use different LeapMotion libraries (as they are not .NET under the covers) but after that small change, it worked fine.

author: iceisfun
author_rank: Regular Contributor
timestamp: September 12, 2013, 04:51:49 pm
content: I have good luck with mono tooAlso I have a 34461A and its pretty awesome, with the firmware update the boot time is about 25 sec which was much longer before.

author: WarSim
author_rank: Frequent Contributor
timestamp: September 12, 2013, 06:16:03 pm
content: Thanks I will put Mono investigation on my todo list.

author: Andreas
author_rank: Super Contributor
timestamp: September 12, 2013, 07:35:23 pm
content: Hello,what do you really want to measure?I think its neither resistance nor voltage.In my opinion you want to measure the voltage ratio between the bridge supply and the bridge difference voltage.So you will either need a DMM with ratio measurement and differential input,or as alternative a simple dedicated ADC development board. (e.g. with the AD7190 ADC converter).With best regardsAndreas

author: bronson
author_rank: Regular Contributor
timestamp: September 12, 2013, 08:46:41 pm
content: Andreas, that's part of the reason I want 6.5 digits. That way I can measure the raw resistance change over different load profiles on different cells at different temperatures to get a baseline, then I can watch how my attempts at differential amplifiers affect the readings.Since the '61a has >10Gohm isolation resistance, it should measure the difference in the wheatstone bridge no problem. At 10V excitation, figure the cells will put out a few tenths of a millivolt differential... Measuring that is easy. I just need to figure out how to amplify it 1000Xish on the cheap -- linear with no noise -- and scale it for a microcontroller's A/D.If I trusted my amps and these load cells more, you're right, I wouldn't need that resolution.Besides, 6.5 digits sounds super handy. Want!

author: bronson
author_rank: Regular Contributor
timestamp: September 12, 2013, 09:10:35 pm
content: Saturation, that's a good point about renting. I figure $150/mo for four months is 60% of the '61a's purchase price, and six months ends up at 80%. And, this sounds like a useful tool even after the project is over. Tell me if I'm missing something... (The $150 is a quote for '10a -- haven't found an available '61a for rent).If I needed 7 or 8 digits I'd rent.

author: orin
author_rank: Frequent Contributor
timestamp: September 13, 2013, 12:51:51 am
content: Quote from: bronson on September 12, 2013, 09:10:35 pmI'd think you'd be better off buying one and selling it after 4 to 6 months than renting one... but I'd plan on keeping it. I wouldn't part with mine for less than I paid for it. (Metrictest had a 10% online discount that got eaten up with taxes and shipping so it was a little over $1100 when the dust settled.) BTW, the warranty extension to 5 years is only $50 - I need to call Agilent to get it for mine. Should have ordered it with the instrument.

author: bingo600
author_rank: Super Contributor
timestamp: September 13, 2013, 01:28:37 pm
content: 3457A on *Bay #360734525681 (Auction)/Bingo

author: bingo600
author_rank: Super Contributor
timestamp: September 13, 2013, 01:31:56 pm
content: Quote from: Tepe on September 12, 2013, 02:21:20 pmThis German company is offering a 3457A Cal. (ISO9000) incl. justage for 99€ + Vat.I got an offer of 153€ incl VAT & Return shipping to DK , that's a very reasonable price.kalibrierlabor.de/Bingo

author: Tepe
author_rank: Frequent Contributor
timestamp: September 13, 2013, 02:00:08 pm
content: Quote from: bingo600 on September 13, 2013, 01:31:56 pmThanks. That is definitely cheaper than what I had found so far.

author: saturation
author_rank: Super Contributor
timestamp: September 13, 2013, 05:06:02 pm
content: If you find you'll use a 6.5 DMMbeyonda projects time line, owning is a better option even if the project's timeline is only 1-2 months; a real issue is justifying the cost of new for a personal purchase. A used DMM with a PC to do the data logging: a 3455a or 3456a typically sells for < $100, 3457a < $300 but you'll need some time to find one in good order, check it out and calibrate it. They support GPIB at best.For rental, its only a clear decision if you keep it for 1-2 months, beyond it it gets blurrier as the rental costs approximate purchase costs.Quote from: bronson on September 12, 2013, 09:10:35 pm

author: nukie
author_rank: Frequent Contributor
timestamp: September 13, 2013, 11:14:36 pm
content: So you just want a multimeter with lots of digits that can spew lots of data in a short time? I suggest comparing accuracy specs of the units especially 90 days and 1 year, not just digits vs cost.There is no point to have a mountain of data when your multimeter is drifting your results will need to be calibrated to the performance of your multimeter. Finally, also consider the cost of calibration as the running cost.

author: Unknown
author_rank: Unknown
timestamp: September 14, 2013, 09:00:50 am
content: Is this about absolute accuracy or about accuracy relative to some reference point? In that case calibration (except zero calibration) is pretty much irrelevant. Sometimes just having a high resolution is enough.If the project only takes a few months, then ongoing calibration is pretty much irrelevant as long as the 90 day stability is sufficient. I don't think you'll find huge differences in accuracy specs between the meters mentioned in this thread.

author: EEVblog
author_rank: Unknown
timestamp: September 15, 2013, 05:26:20 am
content: Just to round out the group, GW/Instek have a 6.5 digit meter too, but about same price as the new lower end Agilenthttp://www.metrictest.com/product_info.jsp?mfgmdl=INSTEK%20GDM-8261(N)

author: Unknown
author_rank: Unknown
timestamp: September 15, 2013, 06:25:20 am
content: I don't see the point of buying off-brand equipment like GW-Instek or Rigol (I don't consider them a decent brand for bench DMMs) unless they are substantially cheaper than Agilent or Fluke equipment. I wouldn't consider the Keithley 2100 either: no point paying for the Keithley name unless you're going to get a Keithley design. The Keithley 2000 (or any of the other Keithley 20xx models) is an excellent competitor to the Agilent 34401A (very similar in most regards) and a fine choice, although usually fairly expensive.To me, the established brands are Agilent, Fluke and Keithley. Some of the older brands like Datron and Solartron have been bought or have pulled out of this market. Any other brand would have to provide substantial advantages for me to consider that, and even then I would first do extensive testing before putting it in production. In the past we've seen QC/build quality issues with the Rigol DM3061(?) and firmware issues in the Keithley/Array/Picotest meter. Apparently designing a decent bench DMM is non-trivial.

author: bronson
author_rank: Regular Contributor
timestamp: September 15, 2013, 08:11:58 pm
content: I picked up an HP 3457A and a Fluke 8840A (why does every part number end in "A"? it's like car models ending in "i") at the De Anza swap meet yesterday. They have good displays and the output looks plausible... Feeling lucky so far.I'll need to spend some time making sure they aren't lying or drifting too bad. I'm not quite sure how I'm going to do that when the best reference I have in my cabinet is probably an LM3940... I'll figure out something better than just running each test with the meters in parallel hoping the 5 1/2 digit Fluke will keep the HP semi-honest.alm's right, at this point I don't actually care too much about absolute accuracy or drift. I want to get a bunch of readings with different amounts of weight on the cells and different excitation voltages across the bridge and look at the deltas. Each measurement will only be a few seconds or minutes apart. That said, this stuff is seriously fascinating... I could very well be on the edge of a debilitating metrology habit.Thanks to Dave and gazelle for naming models I didn't find. Turns out there's a lot out there. Who's up for a 6 1/2 digit shootout?

author: robrenz
author_rank: Super Contributor
timestamp: September 15, 2013, 08:22:08 pm
content: Quote from: bronson on September 15, 2013, 08:11:58 pmBeware!!! it is a very slippery slopeIf you start looking again make sure you consider the Fluke 8846A. I purposely bit my tongue until now

author: bronson
author_rank: Regular Contributor
timestamp: September 15, 2013, 10:23:17 pm
content: Oh, the 8846A was high on my original list. Very high. Love the dot matrix VFD: yes Virginia, you CAN have high contrast and trend graphs. The only hit against it is the price.And it's a pretty big hit.

author: Unknown
author_rank: Unknown
timestamp: September 15, 2013, 11:09:10 pm
content: Quote from: bronson on September 15, 2013, 08:11:58 pmGood score, both are excellent meters in my opinion. HP sometimes releases B models, for example 3468A and 3468B. Just adding a A suffix by default is better then having 'the 3468B and the non-B 3468A, like the Fluke 87 and 87-III.Quote from: bronson on September 15, 2013, 08:11:58 pmIf you're just looking for stability, then connecting both meters in parallel to the same source is a decent solution. If they track, then they are either drifting very similarly, or stable. Of course environmental factors (eg. temperature) might result in the former, but at least you can exclude defects.

author: Attorney
author_rank: Regular Contributor
timestamp: October 06, 2013, 05:37:13 pm
content: Quote from: alm on September 15, 2013, 06:25:20 amConcerning the Keithley 2100, once Tektronix acquired/merged with Keithley, they finally had some leverage to address the firmware issues. Any recently flashed 2100 should now be worthy of the the Keithley or Tek name. I've owned the Keithley 2100 since June of last year and although I do not use its full complement of capabilities, I've detected no bizarre operating issues. Everything, including USB connectivity and supplied software has worked as it should.The 2100 was manufactured by Array in Taiwan. I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A. The Array 3631A is the same supply, with a few more front panel features. It was purchased last year at roughly half the cost of the same Agilent model. Admittedly, I cannot go to Agilent for support if I need it, but I'll assume that risk. I can do that as a hobbyist. If I owned a business that depended on exceptional customer service, then I would pay the higher price for the Agilent-branded product.Paul

author: grenert
author_rank: Frequent Contributor
timestamp: October 06, 2013, 06:25:02 pm
content: Quote from: Attorney on October 06, 2013, 05:37:13 pmI imagine Free e-, our resident HP/Agilent expert will chime in here, but I don't think there's a chance that Array makes the E3631A for Agilent. The E3631A goes all the way back to HP days, now made in Malaysia in Agilent's plant. I think the similarities end with the model number, selected to create confusion between the copy and the real thing.

author: Unknown
author_rank: Unknown
timestamp: October 06, 2013, 09:47:02 pm
content: Quote from: Attorney on October 06, 2013, 05:37:13 pmInteresting, so they finally fixed it after it was on the market for a number of years. Did these fixes also make it to meters sold under brands like Array or Picotest? Too bad they did it after it gave Keithley a bad name. Reviews of the Keithley 2110 haven't been that impressive either (I would never buy it with that cheap crappy LCD), so I'm still not optimistic about future Keithley DMMs.Quote from: Attorney on October 06, 2013, 05:37:13 pmI would agree with grenert that this sounds unlikely. My guess would be that they deliberately used the same model as Agilent (Owon did the same in their upcoming series of scopes by using a Tektronix model number) and copied the front panel layout.

author: Fsck
author_rank: Super Contributor
timestamp: October 06, 2013, 09:56:22 pm
content: Quote from: alm on October 06, 2013, 09:47:02 pmshould be fairly easy to figure out, just post pics of the interior!

author: Napalm2002
author_rank: Regular Contributor
timestamp: October 08, 2013, 05:17:52 pm
content: Fluke 289. How does that convert bec it claims to be a 10,000 count meter. Doesn't give digits.

author: ve7xen
author_rank: Super Contributor
timestamp: October 08, 2013, 05:57:24 pm
content: Quote from: Napalm2002 on October 08, 2013, 05:17:52 pm10,000 counts = 4.5 digits (being generous with the .5 ...). Basically the digit count is the number of digits 0-9, and then add .5 if it has a leading digit with limited range. A 6.5 digit meter will be 1,000,000 count - 9,999,999 count.

author: WarSim
author_rank: Frequent Contributor
timestamp: October 08, 2013, 07:17:34 pm
content: Quote from: alm on October 08, 2013, 05:58:14 pmThanks, I was looking for a video like this for the "special" people at work that insist that cal means adjusted and or repaired.

author: saturation
author_rank: Super Contributor
timestamp: October 09, 2013, 12:36:12 pm
content: Can anyone confirm this definitively? Array was described as the ODM for some Keithley DMMs in the past, and seeing some of their work [ the 3710a eloads for example] shows they design well. These seems very look alike and the Array is 50% cheaper.https://www.eevblog.com/forum/chat/instek-3000-series/msg82910/#msg82910Array vs Agilent/HP!Quote from: grenert on October 06, 2013, 06:25:02 pm

author: free_electron
author_rank: Super Contributor
timestamp: October 15, 2013, 08:28:58 pm
content: BULLSHIT.The e3631 is much older than array, and is a true HP design.if anything that array thing is a cheap knock-off.

author: saturation
author_rank: Super Contributor
timestamp: October 16, 2013, 02:52:46 pm
content: Thanks freee- for that enthusiastic reply. From eevblog archives:https://www.eevblog.com/forum/reviews/teardown-agilent-e3631a-power-supply-%28picture-heavy%29/45/Quote from: free_electron on October 15, 2013, 08:28:58 pm

author: madshaman
author_rank: Frequent Contributor
timestamp: October 16, 2013, 03:21:09 pm
content: +1 on the 3457A, mine's never had a problem.Some day I will find a Keithley 2002 in a dumpster

author: Attorney
author_rank: Regular Contributor
timestamp: October 30, 2013, 01:31:21 pm
content: Quote from: free_electron on October 15, 2013, 08:28:58 pmKnock-off or otherwise -- Place the Array 3631A side-by-side with the HP/Agilent E3631A. Tear it down and look inside. Examining the two, you can detect subtle differences but the component quality is identical. If anything, the nod may go to the Array for its USB interface (if its important to you) and use of some newer semiconductor types since the design of the E3631. The Array has the exact look, feel, and mass of the E3631A right down to the screw heads. I see no firmware bugs with the Array, but then I've not used much of its programming capabilities.Bashing a product is fine, but at least get to know the product before depending on the maligning that goes on when reading the blogs. This would be a good upcoming product comparison for for Dave Jones.Paul

author: Unknown
author_rank: Unknown
timestamp: October 30, 2013, 01:40:45 pm
content: I don't see any bashing of the instrument going on. If the HP/Agilent E3631 pre-dates Array and is manufactured in a different country, then the Array design can only be a knock-off. The quality of this clone may vary from crappy to decent, but it's still a copy. Just like the Hakko soldering station knock-offs of varying quality that are available.It may or may not perform better than the other Chinese low to mid-end power supply manufacturers like Rigol or Atten, but don't kid yourself thinking you bought an Agilent product.

author: Attorney
author_rank: Regular Contributor
timestamp: October 30, 2013, 02:27:57 pm
content: Quote from: alm on October 30, 2013, 01:40:45 pmRight. I don't think there's any self-kidding going on. The Array PS is not an Agilent product. As noted earlier, I said that as a hobbyist, I can live with support that is not up to Agilent's gold standard. If my livelihood depended on the supply, I would look to the Agilent.That out of the way, the underlying issue is whether or not the Array is: (1) anywhere equal to the E3631A in terms of product quality; and (2) is Array involved in any way with the manufacture of recent E3631A supplies? I was told by a manufacturer's rep that Array was building newer E3631As. In my line of business, I live or die by the evidence. Based on my limited research, I do not know as a conclusive fact whether all, or some portion of the newer E3631As are manufactured by Array in Taiwan -- and not Agilent in Malaysia. I am certain we can find an Agilent rep who would refute any claim that recent E3631As are manufactured with outside assistance.Again, put the two supplies side-by-side and compare everything from electronic components, circuit trace layout, machine screws, wiring and grounding practices as well as fit and finish. Array is not Agilent and vice-versa. For sure, Array is leveraging a portion of the model number to their advantage -- and this appears to be upsetting many people. If Agilent has an issue with it, then it would bother me. OTOH, if Agilent has no issue and they use Array in some form, then none of us should take issue with it. Unfortunately, seeking the truth would require getting inside the two organizations.Paul

author: Unknown
author_rank: Unknown
timestamp: October 30, 2013, 03:17:50 pm
content: I think it's obvious that the Agilent E3631A is an Agilent design. I haven't seen any evidence of Agilent outsourcing manufacturing of their own designs. They have sometimes rebadged instruments designed and manufactured by others (the Rigol DSOs come to mind), but not their own designs as far as I know. And even if they did, selling them under the Array name is unlikely to be authorized by Agilent. Why would Agilent license Array to sell these instruments under their own name?Assuming they are not an ODM for Agilent, I consider copying the design and model number is an attempt to trick the customer into buying an Array product thinking it's identical to the Agilent product. I don't like to be deceived; whether Agilent thinks this is worth spending legal fees on is irrelevant to that feeling.

author: Attorney
author_rank: Regular Contributor
timestamp: October 30, 2013, 05:23:56 pm
content: Quote from: alm on October 30, 2013, 03:17:50 pmIt's a good question and a similar situation that Array faced with Keithley (pre-Tektronix). Recall that the Keithley 2100 DMM is clearly an Array-manufactured product. Yet, the same DMM is still sold under the Keithley and Array names, although Array may have a global geography limitation that's acceptable to Keithley. Also, keep in mind that Keithley is still distributing the 2100 so the relationship between Keithley/Tektronix and Array must not have soured any.BTW, at the risk of sounding like an Array cheerleader, the 2100 is one of the most maligned electronics devices I've seen. Granted, in 2007/2008 the maligning was probably warranted. Just like many DSO issues, most folks were quite happy with Array's hardware - but not the buggy firmware. Eight firmware updates later ( in five years) and under the leadership of Tektronix, I think the 2100 is now worthy of the Keithley name.QuoteAt the price level of the Array and Agilent 3631A models, I think most folks are sophisticated buyers who should take the time to conduct their due-diligence to at least ask the question. Of course, that demands a forthright and truthful answer from the manufacturers.Paul

author: Unknown
author_rank: Unknown
timestamp: October 30, 2013, 06:03:18 pm
content: The Keithley 2100 is an Array design, similar to the Rigol scopes sold by Agilent. It's an Array product sold under the Keithley label. Going to a manufacturer and asking to sell their instrument under your name is very different from paying them to produce your design. This would be more similar to Foxconn selling a 'Foxconn iPhone'.

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: October 30, 2013, 10:13:22 pm
content: I use a Fluke 8846A.. its serves me well, its so dear to me that i have it mentiond in my prenup..The wife will get the kids.. i my Fluke..

author: scopeman
author_rank: Frequent Contributor
timestamp: December 27, 2017, 01:24:12 am
content: Bronson,I would guess by now that you know that you can get an extra digit of resolution when using the HP3457A on GPIB. Something they do not show on the display. I guess of they did that it could hurt sales of higher resolution meters although at the time I think the HP3458A was the next step up and considerably more expensive.By the way how did you make out with the original project you purchased the mete for?SamW3OHM