Keysight DMM - Yay or nay? - Page 1
Forum section: electronics / testgear

author: Traceless
author_rank: Frequent Contributor
timestamp: March 01, 2022, 11:25:06 pm
content: Currently I looking for a better multimeter. A hot candidate was the Keysight 34465A, specs-wise my only complaint is the meager capacitance range. However after readingthisI have second thoughts about going with Keysight. Unfortunately there don't seem to be too many good alternatives at that price point. The Keithley DMM 6500 looks nice but the touch screen is a deal-breaker. The Keythley 2000 is missing capacitance mode entirely, which is also a deal-breaker. The Rohde&Schwarz HMC8012 seems a bit outdated and overall too expensive for its specs. I also consider the Siglent SDM 3065X, it has a much better capacitance range. Otherwise it can't quite keep up with the Keysight 34465A but it is also considerably cheaper.Is there any other contender I should consider? Are Keysight 34465As repair friendly or does one have to rely on the virtually non-existent support? Does the Keysight 34465A or the SiglentSDM 3065X have any quirks I should know about before making a choice?

author: tautech
author_rank: Super Contributor
timestamp: March 01, 2022, 11:32:09 pm
content: Quote from: Traceless on March 01, 2022, 11:25:06 pmMainly to get the latest firmware into it ASAP to fix the boot freeze the odd units have.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 02, 2022, 12:03:45 am
content: The capacitance measurement on the DMMs is usually not really competative to a dedicated RCL instrument. This starts with an often not so well defined frequency and bias. With electrolytic caps 1% accuracy only makes sense if you also know the frequency.The KS 34465 uses digital RMS and this way have a much faster response in AC mode than old style analog RMS chips. The stability can also be quite good.The SDM3065 has a 20 V range with high impedance, while the KS meter only some 10(12?) V. This can make a difference.Modern DMMs are rather reliable and a repair is not very likely. If a repair is needed it gets complicated, as for the newer meters there are little repair instructions or schematics provided. Custom parts, especially resistor arrays and special relays can limit what can actually be repaired.

author: Cerebus
author_rank: Super Contributor
timestamp: March 02, 2022, 12:17:46 am
content: Don't be distracted by capacitance measurement on DMMs, it's a gimmick that's therejustto affect decisions like the one you're trying to make and tip your final decision between near rivals. Forget about choosing a DMM on its capacitance measuring and treat it as a bonusif and only if allthe other measurement capabilities meet your requirements.If you're lucky the capacitance range on a general purpose DMM will give you a vaguely accurate capacitance measurement by feeding the capacitor from a constant current source and timing the resultant slope between two voltages, it won't measure the voltage, current and phase produced by passing a sine wave at defined frequencies through the capacitor the way a proper LCR bridge will. It won't give you anything other than the raw capacity either, you won't get ESR, Q, \$tan \delta\$ or any other such parameters. A £100 LCR meter will give you better and probably more accurate measurements.

author: bob91343
author_rank: Super Contributor
timestamp: March 02, 2022, 12:26:27 am
content: I agree. Don't try to measure capacitance with a DMM. I can measure capacitance with any of a number of instruments. I have two bridges, a VNA, a multi component Chinese tester, and a DMM with capacitance ranges. Plus a couple of Q meters and an RX meter.The bridges win, hands down. The VNA does well at higher frequencies. The Q and RX meters are great but they are boat anchors and a nuisance to drag out to use. The DMM sits in the closet in a box. The Chinese tester is okay but I always verify its reading with another instrument.If I really care about a measurement I will always use a bridge.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 12:32:19 am
content: Thanks to everyone for the feedback so far.@Kleinstein, @Cerebus, @bob91343: I do know that DMM capacitance mode is not the holy grail, for me it is merely a convenience function. For instance when I do replace caps I like to do a quick and dirty check on the replacement cap just to see if capacitance is in the right ball-park. I already own a proper LCR-Meter (Matrix MCR-5200), but for simple stuff like that I tend to just use the DMM and don't bother to grab the LCR-leads out of the drawer and hook them up.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2022, 12:33:05 am
content: Quote from: Cerebus on March 02, 2022, 12:17:46 amBut still it is very handy to have. I use the capacitance measurement function on my bench DMM (in most cases not a Keysight though) regulary to check the value of a capacitor quickly so see what value I mounted on a board while tweaking a circuit. This works from a couple of tens of pico-farads since capacitors commonly used are mostly in the E6 values range.@the OP:Choice of DMM between the Keysight 34465 and Keithley (Tektronix) DMM6500 is a though one. A couple of years ago I bought the 34461 but back then the DMM6500 didn't exist yet. Nowadays I might have choosen the DMM6500. Don't get too winded up about a touch-screen; when the interface is designed around a touchscreen from the ground up, then it works way better than buttons. What is important IMHO where it comes to precission instruments is pedigree; knowing how to build a proper 6.5 digit DMM. Both Keysight and Keithley have a long history with developing & producing higher end DMMs.Forget about repairing though but then again test equipment has a lot less parts then in the old days so there is a lot less than can get broken. If you are worried about repairs costing a fortune, you can get an extended warranty contract.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 12:47:18 am
content: Quote from: nctnico on March 02, 2022, 12:33:05 amI already pretty much ruled out the DMM 6500, the meter is probably good but I very often wear work gloves likethis onewhich might be a problem with a touch screen plus I really prefer buttons over touch interfaces.Quote from: nctnico on March 02, 2022, 12:33:05 amThat option would indeed be interesting but from what I understandKeysight does no longer support non-business customers. Do you know a way to get such a contract as hobbyist?

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2022, 01:22:40 am
content: Quote from: Traceless on March 02, 2022, 12:32:19 amGenerally that approach works but not always as you can have a cap measure within 10% of its nominal value however its ESR can be miles off.I used a borrowed bridge for a few years but the pissing around nulling it drove me nuts and a dedicated LCR meter I wasn't keen on and as I was getting into SMD a decent set of SMD tweezers were acquired instead which are much faster and more convenient to use plus it can quickly measure all those unmarked SMD caps. Still, I probably use it more on TH components than SMD.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2022, 02:17:47 am
content: Quote from: Traceless on March 02, 2022, 12:47:18 amBuy it through a distributor. Just give a reputable one a call and ask.

author: thm_w
author_rank: Super Contributor
timestamp: March 02, 2022, 02:29:22 am
content: Quote from: Traceless on March 02, 2022, 12:47:18 amMarco reps is that you?Touchscreen gloves are a thing as well, or stylus:https://www.uvex-safety.com/en/product-group/uvex-phynomic-airlite-touchscreen-safety-gloves/But yeah if you want a button instead I get it.

author: Zucca
author_rank: Unknown
timestamp: March 02, 2022, 03:15:55 am
content: Quote from: Traceless on March 01, 2022, 11:25:06 pmNot really, no schematics. It depends on your brain and luck. That said if you post in the repair section well there is an EE army ready to help.For free. KS pissed me off too with the hobbist thing, but sometimes a good community can compensate.

author: mawyatt
author_rank: Super Contributor
timestamp: March 02, 2022, 04:39:30 am
content: We have and use all three DMMs, 2 KS34465A, DMM6500 and SDM3065X.The SDM3065X is the weakest of the 3, it doesn't have many of the features of the others and doesn't seem in the same league, something mentioned about the long history of KS (heritage with the HP34401A) and Keithley with DMMs seems to be present in their usage. However the SDM3065X also is ~1/2 the cost, so from a value standpoint it's quite good.The KS34465A just does everything well, and is very easy to use and quickly get to what's important.....accurate measurements!! Being older still prefer the buttons to menus of the DMM6500.The DMM6500 excels in the graphics area, almost like having a low sweep rate scope. Also has the lower ohms ranges, but doesn't have the lower current range of the KS. When long term measurements are required we turn to the DMM6500.Both the KS and DMM6500 have switchable rear inputs, we've found these handy and hang thermistors from and record local ambient temperature without having to remove leads from the front inputs. The KS uses a pre-aged/selected LM399 reference, believe the DMM also uses a pre-aged reference but don't think the SDM3065X uses a pre-aged LM399.We purchased the first KS34465A a couple years ago, then the SDM3065X, then the DMM6500 about 6 months ago. When we needed another quality DMM a month ago, it was between the KS and DMM, and finally decided on the KS.Edit: The cap measurements are OK, more accurate on the KS and DMM. However, consider a dedicated LCR meter like the DE-5000, much more accurate, versatile and useful in every respect.Best,

author: Domitronic
author_rank: Regular Contributor
timestamp: March 02, 2022, 08:47:17 am
content: There is also a bug in the resistance measurement function of the DMM6500 that might be considered when choosing a multimeter. The DMM6500 is not able to measure resistance of coils and transformers in certain measurement ranges properly. In my opinion this is surprising and somehow embarassing for Keithley. But since it is acutally a hardware issue i guess it can't be fixed in software. As far as i remember the current source for measurement starts to oscillate when the multimeter is in 100 Ohm range and an inductive load is connected. This also screws up the autorange function. There is a thread about the issue in this forum.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:01:22 am
content: Quote from: tautech on March 02, 2022, 01:22:40 amYou're right, I know. I like to give "new" replacement caps the benefit of a doubt, based on the (probably inaccurate) assumption that if they were stored too long/under wrong conditions or have a manufacturing defect I'll see a significate deviation from the nominal capacitance. For diagnosis on old/used stuff I always double-check with my LCR-meter.Quote from: nctnico on March 02, 2022, 02:17:47 amI'll give that a try.Quote from: thm_w on March 02, 2022, 02:29:22 am*grin* I wish I were, I don't think Marco would bother with buying "petty little 6.5 digit DMMs". Among others he owns an HP3458A, a Solartron Schlumberger 7081, a Keithley 2002 and an Advantest R6581T.Quote from: Zucca on March 02, 2022, 03:15:55 amGood point the community here is awesome. Still I dislike it when vendors become this arrogant in which case I like to vote with the wallet. In this particular case there don't seem to be many alternatives though.Quote from: mawyatt on March 02, 2022, 04:39:30 amYes that was my feeling as well. Currently the SDM seems to be good enough, and delivers the best bang for the buck but that's what I thought about my current DMM as well and now I'm occasionally frustrated with it (reason explained below). So I'm trying to avoid making the same mistake twice.Quote from: mawyatt on March 02, 2022, 04:39:30 amYeah as mentioned, I regard the DMM-capacitance mode as a convenience feature not as a precision-thing. I already own dedicated LCR-meter, theMatrix MCR 5200.@Domitronic: Thanks, that is a very interesting point. Speaking of "screwing up auto range". My number one complaint with my current DMM is that auto range is excrutiatingly slow, also AC current measurements tend to have a long delay to the point where I'm now convinced that my DMM is actively trying to kill me (sometimes it does not pick up mains voltage in a reasonable time frame). That's why I nicknamed itChristine. Can I assume that, aforementioned bug aside, KS, Keithley and Siglent don't suffer from that problem?

author: Kleinstein
author_rank: Super Contributor
timestamp: March 02, 2022, 09:41:47 am
content: Analog true RMS is naturally slow. To get good accuracy at 20 Hz it needs a rather slow settling filter and this gives a naturally somewhat sluggish reaction. Some chips are worse than others in this respect (worst case things get even slower at low votlage), but even the good ones are slow. One should still see a first reaction reasonably fast, but the final accuracy may well need 5 seconds of waiting.If implemented poorly AC autoranging could suffer quite a bit, though there are ways around this.The DMM6500 and KS346x meters use digital RMS and can react quite fast in AC mode (stable final reading after some 200 ms - don't know the details on these meters). One can already see the difference with handheld meters - some of the newer, more low cost true RMS meters use digital RMS and offer surprisingly fast AC settling.The SDM3065 uses a classical analog RMS chip.At a slightly higher price point there is also the Fluke 8845 DMM as a possible candidate - not my favorite, but just to add to the list.Occasional failing AC is a potential risk. It could be from a relay problem - this is indeed bad and a good reason not to trust any such meter to check if there is no mains. At least German regulations wants you to use a dedicated tool for this and not a normal DMM, let alone a bench DMM.

author: ch_scr
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:42:38 am
content: My father has the HMC8012 as his bench DMM basically since it came out. It is not a bad little unit,butit came out around the time of the Hameg merger and it feels like they forgot to continue FW development. The last firmware is from 2017. And not because the FW on the unit is perfect, it's not Rigol-level-buggy, don't get me wrong, but the control concept feels off and is not totally consistent, some buttons seem almost unused on the UI. And a modern DMM with color LCDbut without plotting? Seriously? There are basic statistics but no histogram or tracking view - soo much lost potential there alone! The interleaved voltage / current measurementwithout relay switchingis a very nice feature for a general bench DMM, much appreciated, as is the fast boot time. It is not a bad instrument, works well in general, but it is really let down by what feels like abandoned development.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 10:29:03 am
content: Quote from: Kleinstein on March 02, 2022, 09:41:47 amI don't think there is a defect with my DMM. I think what is going on is this:When I take an AC measurement the DMM takes time - 5s sounds about right. The catch is: My DMM seems to display nothing until it has a stable reading (-> 5s delay plus the autoranging delay that varies depending on how many ranges it has to cycle through). Now when there is bad contact, due to oxidized or dirty joints or just because the probes are sliding a bit when applying pressure and contact is lost for a fraction of a second the measurement resets and the DMM starts over trying to get a stable value. So basically AC measurements are not constant time but vary depending on the current circumstance. So you can never be sure if you waited long enough. I ordered some new super sharp probes to see if that helps with the issue.Quote from: Kleinstein on March 02, 2022, 09:41:47 amI had replaced the fuse in a 24V SMPs adapter and just wanted to check if I had mains at the input filter after replacing the fuse. I didn't get a reading in time on my bench DMM. All plugs were connected and my isolation variac was turned on, also I checked the fuse. Knowing about the delays I got suspicious grabed my Aneng 8009 and voila mains present. The Aneng is just a lot faster than the bench DMM. Workarounds are the following:- Patience (and probably better probes)- Select range manually- Increase the trigger speedThe problem here is that the meter does not save the trigger setting when turned off, also the least significant digits become very jittery when increasing the trigger speed. Ultimately that means that I need to keep manually switching between low and high trigger speed, depending on if I want to measure presence of mains or do high precision measurements on the secondary side. All of this is doable and otherwise the meter is really good but those constant user interactions, switching between low and fast trigger and manually changing the range get really annoying. Luckily that only is an issue when I work on PSUs in other cases the meter does a very good job.Quote from: Kleinstein on March 02, 2022, 09:41:47 amGood tip I added the Fluke to the list, though feature-wise the even more expensive 8846A is probably closer to the 34465A.@ch_scr: Thanks for reporting these experiences. That confirms my suspicion that the HMC8012 does not offer a good value (any more) for its price.

author: Markus2801A
author_rank: Regular Contributor
timestamp: March 02, 2022, 01:09:43 pm
content: HelloI just want to bring in the GW-Instek GDM-906x Series with two types namely GDM- GDM-9060 and the GDM-9061https://www.gwinstek.com/en-global/products/detail/GDM-906xWhat do you guys think of them?Kind regards!Markus from Austria

author: mawyatt
author_rank: Super Contributor
timestamp: March 02, 2022, 02:25:44 pm
content: We also discovered some charge injection on the DMM inputs, and the DMM6500 seemed to have slightly more.https://www.eevblog.com/forum/testgear/dmm6500-glitch-on-dcv/msg3753929/#msg3753929Best,

author: Cerebus
author_rank: Super Contributor
timestamp: March 02, 2022, 04:12:51 pm
content: Quote from: Traceless on March 02, 2022, 09:01:22 amCue George Thorogood and the Destroyers:Da da da da da dum de-dum de-dumDa da da da da dum de-dum de-dumBad to the boneDa da da da dumBad to the boneDa da da da dumB-b-b-b-b-badDa da da da dumB-b-b-b-b-bad

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 06:51:16 pm
content: @cerebus: Yep, pretty sure they played that song during the assembly of my DMM as well

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 08:09:35 pm
content: Quote from: Markus2801A on March 02, 2022, 01:09:43 pmHey Markus, thanks for bringing these meters to my attention. I took a quick look at the GDM-9061's specs and it seems that the Siglent SDM 3065X is more accurate, also the Siglent has 2200000 counts vs the 1200000 counts of the GWInstek plus the GDM-906x models seem to be more expensive. Unless the GWInstek has some trick up its sleeve that I missed while skimming over the specs the SDM 3065X would be the better option.

author: blackdog
author_rank: Frequent Contributor
timestamp: March 02, 2022, 08:28:55 pm
content: Hi,I have 2x a 34461A 1x 34465a and a Keithley 6500.The reason I bought a Keithley 6500 in December 2021 is because I wanted to try how another brand does in terms of 10V stability.My 34465a was a big disappointment, the Autocal is Markerting Bullshit. my instrument has been away from home for 6 months to Malaysia for verification of the problem that when you do an autocal it drifts out again within 20 minuter if the temperature in the measuring instrument remains stable.The service here in Holland from KEySight was excellent, I got a loaner instrument and this loaner instrument had exactly the same problem.Keysight Maleysia told me that the drift that occurred remained within the daily average and therefore they can't do anything about it...Don't buy the 34465a for the autocal! but the instrument has more useful features that might make it worth buying this type anyway, like the ezxxtra filtering that is possible, just to name one aextra feature.My Keitley DMM6500 sat now for almost two months and the deviation on the 10V range stays within +-1PPM at varying lab temperatures, this is very good, and better than my three Keysight 3446x series meters.As far as the interface is concerned, at the moment my preference is slightly with the KeySight.But I haven't had time enough to do e.g. scripting on the Keithley meter.So you will have to make your own trade-offs as to what is best for you.Also see if temperature measurements are important to you so you can connect accurate sensors to the DMM you choose.Kind regards,Bram

author: Kleinstein
author_rank: Super Contributor
timestamp: March 02, 2022, 08:36:45 pm
content: The GDM906x meters seem to have rear terminals, that I don't see with the sigilent.At least the GDM9060 seems to use a comparable SD ADC chip to the Sigilent.There is also a Teledyn (T3DMM6-5), that seems to be essetially the same as the Sigilent - possibly an OEM build.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 08:45:27 pm
content: @blackdog thanks for reporting back. Awesome that you have all those meters and can provide such a nice comparison, altough this makes my life a *lot* harder now. I really do like the Keithley and its features, but I'm really struggling with myself if I can/want to accept the touch screen. To make things even harder I also stumbled across the KeithleyDAQ6510which now also entered the ring of contenders, unfortunately it is also touch-controlled.

author: tautech
author_rank: Super Contributor
timestamp: March 02, 2022, 08:46:01 pm
content: Quote from: Kleinstein on March 02, 2022, 08:36:45 pmCorrect, no rear inputs on SDM3065X unless you get the 16ch scanner card but these have limitations for voltage and current.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 08:53:16 pm
content: @Kleinstein, @tautech Yes you're right the Siglent doesn't seem to have rear terminals, good point. Also the T3DMM6-5 really looks like a rebranded Siglent, it seems to be much more expensive though (according to a quick google shopping search).

author: blackdog
author_rank: Frequent Contributor
timestamp: March 02, 2022, 08:57:42 pm
content: Hi, Traceless,You're welcome, I also have two Tektronics DMM4050 which are similar to the Fluke versions.Of these I can say that at the 10V DC range they are also very stable.They were last calibrated about seven years ago and the deviation is now about 4PPM at the 10V range at normal room temperature.I don't think I would buy this model (Fluke/TEK) now. don't get me wrong, these are very good measuring instruments, but the price... silly Fluke.One negative point is the input sockets on the front, on one of my two meters I have already had to repair it.The machanic design of the connection bushings is a big Marketing mistake.I am very careful with my measuring instruments but it still breaks down.Soon, on the second meter, I will also redo the soldering of the input bushings.Software for logging is also not widely available from the Fluke/TEK meters, that is also a consideration when weighing.The two TEK meters are my workhorses, so don't think now that I don't value them. :-)Kind regards,Bram

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:12:57 pm
content: @mawyatt to rule out that blackdog just had very bad luck with his KS meters, did you observe similar auto-cal issues with yours compared to the DMM6500.Also since both of you @mawyatt and @blackdock have access to a DMM6500, can you by chance tell if a) I can ignore the touch screen and access all functions with the buttons next to the display and b) if the touch screen can be operated with gloves likethis?

author: blackdog
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:30:03 pm
content: Hi Traceless,The Keysight meters are not bad! I use them almost daily.I have received over the years very good support from KeySight Netherlands!But the Autocal is just not well done and not worth spending money on if that is the only function why you buy a 34465a instead of a 34461a.The calibration/reports from Keysight very also very good, If you buy a 34461 or a 34465a you get a nice calibration report.With the Keyley DMM6500 you only get one a4 with on it that it is calibrated.I don't know if this difference is important to you.Kind regards,Bram

author: mawyatt
author_rank: Super Contributor
timestamp: March 02, 2022, 09:52:35 pm
content: Quote from: Traceless on March 02, 2022, 09:12:57 pmHaven't experienced any Autocal issues with either KS34465A, and the DMM6500 & two KS34465A agree well with our home brew 10V references based upon LM399 (2) & LTZ1000. Like mentioned we also wanted to "see" how good the DMM6500 was compared to the KS34465A and not having any experience over our career with Keithley somewhat concerned about how the DMM6500 would preform. Well it performed admirably and we have no concerns recommending this superb instrument. As mentioned the KS and DMM are good just about everywhere and have specific areas where they excel. Honestly you can't go wrong with either.No, you can't access all the menus on the DMM6500 with buttons, you'll need to employ the touch screen. Don't have any gloves like shown, but did just use Nitrile Exam Gloves, and no issues with DMM menus.Best,

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:55:13 pm
content: Hi Bram,well the main reason I chose the 34465A over the 34461A is that it has a much higher reading rate 50k rdgs/s vs the 34461A's 1k rdgs/s, I just want to avoid the grief I have with my current meter, which has very slow auto ranging and sluggish AC readings. Aditionally the 34465A's 1µA range is nice to have. Other than that any of these meters probably even the Siglent is more than good enough for my purposes and a quantum leap forward from what I have currently. If I get a new meter this is probably going to be a life-time purchase (unless the device breaks down and can't be reparied) so I do my best to make the right call this time, even if that means stretching my budget a bit.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 02, 2022, 09:59:31 pm
content: @mawyatt: Thank you very much for reporting back so quick and also for doing the glove test, you are awesome!

author: blackdog
author_rank: Frequent Contributor
timestamp: March 02, 2022, 10:07:20 pm
content: Hi mawyatt, :-)Regarding the Autocal, Keysight investigated that problem and came to the same conclusion as the measurement report I sent them.They sent me a measurement report showing the same effect measured in their factory as what happened to me in my lab.If you use the Autocal function at e.g. 25C lab temperature and say the Keysight DMM shows +2PPM difference from its Cal temperature.The meter usually corrects that with Autocal, but usually after about 20 minutes your meter will read the same value as before the Autocal function.This also happens when the internal temperature of the DMM remains the same.Kind regards,Bram

author: blackdog
author_rank: Frequent Contributor
timestamp: March 02, 2022, 10:17:33 pm
content: The AC ranges of the 3446x series meters are really good, very broadband and you have the possibility of three measurement speeds for the low frequencies.Also, the dB function of the 3446x meters is very useful with a very high resolution.As for Autorange, that feature on my multimeter is using less and less.I usually choose a range 1 step above the range needed for maximum resolution, the meter is then very fast.Also choose the number of NPLC well, here the basic setting is 10 NPLC, but depending on the measurement function it can also be 0.1 NPLC.The digitizing function I actually do not use, but for you it may be important.The Keithley is a lot faster in this respect.I think you will definitely be happy with a 34465a DMM even though I have problems with the autocal measurement function of this model!Kind regards,Bram

author: mawyatt
author_rank: Super Contributor
timestamp: March 02, 2022, 10:27:48 pm
content: Quote from: Traceless on March 02, 2022, 09:59:31 pmThanks. If this is your lifetime purchase then this tilts the scale in favor of the KS since it "may" contain some heritage from the timeless HP34401ABest,

author: mawyatt
author_rank: Super Contributor
timestamp: March 02, 2022, 10:32:44 pm
content: Quote from: blackdog on March 02, 2022, 10:07:20 pmHi Bram,We hadn't noticed that drift, and will look for it next time we get the pair of 34465A & DMM6500 "looking" at the references for a few days. Will report what we find.Thanks for pointing this out.Best,

author: Cerebus
author_rank: Super Contributor
timestamp: March 02, 2022, 11:42:25 pm
content: Quote from: mawyatt on March 02, 2022, 10:27:48 pmTechnologically the TrueVolt series are very different from the 34401A, in fact the technological basis of the range was first tried out in the 34410A. The 34410A is the last that HPAK published schematics for - a comparison of those with the 34401A's schematics shows a whole raft of differences, in particular the core ADC is totally different. The TrueVolt series, in particular the 34461A, was explicitly designed to be compatible with the 34401A both from an operation and automation point of view, and in the case of the 34461A, identical measurement characteristics so that they could be a drop-in replacement for the 34401A.

author: razvan784
author_rank: Regular Contributor
timestamp: March 03, 2022, 10:18:32 am
content: If I may offer a personal opinion:* if you are after precision, accuracy and stability, and you absolutely want a new meter, I would skip anything besides Keithley and Keysight. I used a 34461A and liked its interface. I think i'd like the 6500 interface better, but haven't had the opportunity to try it.* if you are after repairability, I would skip anything new and go for a used 34401A in good condition (or even better, a 34410A if you can find one for a reasonable price). These can be hooked up to a PC via RS-232 (or even to something like a Raspberry Pi) where you can easily do logging, fancy graphs and whatnot. An old Keithley 2000 is also an option (I also like its interface better) but these are not as easily repairable - the circuitry is more complicated and official schematics have not been published.For a general-use DMM, sure, capacitance is nice to have, and stuff like continuity and diode mode are important. For a precision bench DMM on the other hand, I don't think those are relevant selection criteria. I also use a DE-5000 for capacitors and I'm quite happy with it.

author: blackdog
author_rank: Frequent Contributor
timestamp: March 03, 2022, 11:23:08 am
content: Hi,First I want to make this clear, I can still recommend Traceless the 34465a from Keysight it is not a bad DMM!The things I show below like this concern small deviations at the PPM level when using the Autrtocal function.My assumption when I bought the 34465a was that if my lab temperature was stable at 26C and I used the Autocal function then the few PPM that the Autocal function corrects,would remain stable if the temperature in the measurement environment did not change.The corrected value of the autocal function drifts downward at two instruments I tested.And a 34465a reference meter at Keysight's factory to which my meter was compared had the same drift after using the Autocal function.And again, this does not make the 34465a a bad DMM, just that the Markereers at Keysight wanted an extra feature on their 34465a version to be able to sell the 34465a for a higher price.So I paid the higher price, but the functiue doesn't work well, and I find that a bit sad.I can still take accurate measurements as needed as I also have an Agilent 3458a standing by. but for good stability this DMM will need to be on for at least 12 hours,I choose to keep 24 hours on and that also means the sound of an F16 next to you from the fan.OK some pictures,Here you can see the drift on my 34465a after using the autocal function.This meter was paralleled to two 34461a and my 3458a DMM for verification so that I had some assurance that there were no measurement errors involved..This is one of the measurements the Keysight factory made of my Unit and their reference 34465a DMM.My 34465a is the orange line and the blue line is the reference DMM.In the green frame that I placed in the picture is a special test from Keysight, as far as I understand it, there the Autocal function that is always present in this DMM series is disabled.I was told that this function is not available to the users, as it is only for the fabrication or calibration process.But the drift in both instruments is readily noticeable.And again, the orange line is again my DMM..I have no idea what the behavior of the Autocal function is at larger temperature deviations, say e.g. as a 34465a in a 19-Inch rack mounted with equipment and whether the Autocal will also drift more percentage-wise.It may well be that the few PPM I have experienced is the "base" drift and if the ambient temperature is e.g. 25 degrees higher in a 19-Inch rack that this base drift I am measuring will cancel out against e.g. 15PPM drift that the Autocal function corrects.I have no way to check this, I do not own a climate box to do good measurements in this regard.Some tipsIf you are going to make precision measurements keep in mind these things, among others:Provide a measurement room with a stable temperature.No varying Sun, no drafts.Do not place your DMM in a place where it is heated by other measuring instruments.Clean the inputs of your DMM regularly with alcohol and Q-Tips.Preferably do not use banana connectors, they are slow to warm up and if you do want to use them, make sure they are gold plated and also cleaned with alcohol.For most precision measurements use a pair from a CAT5e cable that is full copper and a pair of Q-Tips to secure this pair in the inputs of the DMM and clean them with alcohol.Keep the wiring as short as possible, wiring always twisted!Keep telephones and other transmitting equipment away from your test rig, and yes, also the phone in your pocket or that of your colleagues.Also think about SMPS power supplies, these are often lighthouses as far as EMC is concerned, always think about that when you have strange outliers in your measurements, it's really not always the 1/F noise of your voltage reference or your D.U.T.I'm sure a good number of people here on the forum can add to this list with tips.My TEK DMM4050 meters and also my Keithley 6500 do not have an autocal function for the user, so I cannot compare my 34465a with that,And again the 34465a is NOT a bad DMM!I hoop this helps and if there are question, i like to hear them.Kind regards,Bram

author: Traceless
author_rank: Frequent Contributor
timestamp: March 03, 2022, 09:56:10 pm
content: Quote from: razvan784 on March 03, 2022, 10:18:32 amI actually do like old DMMs and also thought about that but there are a few catches. For some reason the good brands are unobtainum in Germany. You do find stuff on ebay but:- prices are stellar- they're often in pretty rough shape (cosmetically) and sometimes technically have tired VFDs etc.- you don't know if the meter has any quirks/defects- I don't know when they were calibrated last and if calibration is still goodSince I don't have any equipment to test the accuracy and recalibrate such a meter I'll likely end up having to send it to Keysight/Keithley for calibration who will then tell me that there are a few issues with the meter that need to be fixed along with a 1000€ quote for repairs and calibration. At that point just purchasing a new one will be cheaper plus I have warranty.Once I actually own a proper multimeter I can use as reference I can totally see me buying a damaged used one for restoration - just as a fun project/learning experience.Quote from: razvan784 on March 03, 2022, 10:18:32 amI think they arestill sold newtoo bad though, that there is not much documentation around, but I assume that is true for most modern DMMs. If I really want good documentation I'll have to look for the HP branded stuff (which is really hard to get here).Quote from: razvan784 on March 03, 2022, 10:18:32 amSince this DMM is going to be my only (bench) DMM I'd rather not like to miss out on diode mode, my secondary meter currently is an Aneng 8009. I could live without capcitance though if I absolutely have to.

author: tautech
author_rank: Super Contributor
timestamp: March 03, 2022, 10:04:49 pm
content: Quote from: Traceless on March 03, 2022, 09:56:10 pm100% !Still for basic use the purchase of say of a DMMCheck provides a sanity check that accuracy is appropriate for your needs otherwise the Voltnut rabbit hole awaits.You may not be aware Defpom has a website for adjusting Cal constraints for the SDM range:http://www.thedefpom.com/siglent_sdm_calibration.php

author: Kleinstein
author_rank: Super Contributor
timestamp: March 03, 2022, 10:19:02 pm
content: The Keithley 2000 are no longer sold new, but there are rather similar meters as Keithley 2100 or Picotest M3500.In Europe the situation with used higher grade DMMs is not as good as in the US.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 03, 2022, 10:37:26 pm
content: Hi Bram, thank you very much for the detailed explanation and the effort to post your measurements and compiling all the high precision measurement tipps here I really appreciate that. Also I find that autocal-issue you found quite interesting and would be curious if this is a hardware design flaw or a firmware bug. Probably only Keysight can answer that question. I think you should post yor discovery in the Metrology Forum I'd love to see where the discussion about this goes.As you say the 34465A is still a good meter despite the autocal issue, the number one question I'm asking myself now is: "Does the 34465As autocal issue make the 34461A actually the better meter just because it is not constantly drifting and recalibrating?"Ultimately I probably shouldn't worry too much about the autocal problem because the environment conditions the meter will operate under are far from ideal. May lab is right under the roof and like in most german houses there is no air conditioning. That means that especially in the summer time I'll have temperature fluctuations from around 21-26°C in the morning up to 38°C in the afternoon, and I'll have to open the window because otherwise I'll be cooked alive. (Mental note to self, don't do precision measurements in summer but rather go out for an ice cream instead) At that point the auto-cal issue is probably going to be negligible.In autumn, winter and early spring the temperature will be much more stable though also not perfect (likely between 21 and 24°C). Also I usually only warm up my meters for 5 minutes or so, they don't run continously.

author: nctnico
author_rank: Super Contributor
timestamp: March 03, 2022, 10:45:08 pm
content: If you want to do really precise measurements then you'll need a room with climate conditioning (temperature + humidity) but by that time you enter calibration lab territoy. I'm not saying a 6.5 digit DMM is useless, but you'll have limitations in normal room / office conditions.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 03, 2022, 11:10:38 pm
content: @nctnico: Well I could get an 3458A IIRC those have an oven to compensate for room temperature- no just kidding. The 34465A is probably already overkill for most/all of my applications. I'm just a hobbyist and don't do high precision circuit design or anything like that.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 03, 2022, 11:12:25 pm
content: The autocal function is not so much about a changing temperature, but more about using the meter for many years without calibration. The ACAL function does internal tests to remeasure resistor ratios and this way can reduce the drift. This can also help against temperature dirft, but the main point is the long term drift. It is rare that one needs a really accurate reading with a temperature way off.AFAIK one does not have to use ACAL on the 34465 and the 34461 does no offer this option / point.It is just inconvenient that the function does not seem to work all the way as intended. Chances are this is a SW problem, maybe related to some HW oddity. For the 34470 the ACAL seem to be even more problematic and for some reason KS seem to still have not really fixed it. They seem to have a problem if ACAL actually makes a difference to the normal cal factors. The problem with the 34465 may well be related though there are differences.I still have some hope that they finally will fix it - though one never knows. Some SW problems persist until the product is obsolete (e.g. extra LF noise in many Keithley meters, that is likely due to a SW quirk).The ADC in the 3446x series is not the absolute best INL and linearity is an important factor in how good ACAL works.The 34465 still has more current ranges, higher speed and tighter specs, though much of the internals seem to be very similar.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 03, 2022, 11:48:56 pm
content: Quote from: Kleinstein on March 03, 2022, 11:12:25 pmSo autocal is probably worthwhile despite the drift then, since I plan to use the device for a long time and probably will never send it off to a lab for calibration.Quote from: Kleinstein on March 03, 2022, 11:12:25 pmAccording to Bram you can't turn off autocal on the 34465A, so if I really didn't want autocal I'd have to go for the 34461A.Quote from: Kleinstein on March 03, 2022, 11:12:25 pmWho knows maybe if Bram starts a thread about his discovery in the metrology section and enough people start investigations, it might get Dave's attention. If he makes a video about that there is a good chance that Keysight will address the problem, unless it really is a HW issue that is not fixable via firmware.Quote from: Kleinstein on March 03, 2022, 11:12:25 pmThe high speed is exactly what im interested in. Also the additional ranges are nice.

author: nctnico
author_rank: Super Contributor
timestamp: March 04, 2022, 12:00:15 am
content: As an owner of the 34461A I do have to say that the resistive range is lacking at the lower end of the range. Despite that the 34461A has 4 wire measurement, it is not suitable to measure milli-Ohm resistors. It would need an extra (lower) range for that. The DMM6500 lowest resistance range is 1 Ohm where the lowest range on the 34461A / 34465A is 100 Ohms.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 04, 2022, 03:14:14 am
content: I spent a lot of time considering the 34465A, the 6500, and some other bench DMMs. I went with the 34465A.I also am not a huge fan of touch screens but I believe that done well they can be not only be good but for some functions better than buttons. While so far I'm mostly into buttons, based on some other products I own I believe that with a well done UI a combination of touch screen and buttons might be ideal. If you can do everything you want with buttons and then also do more with the touch screen you can easily and enjoyably grow into the use of the touch screen.As for accuracy I think both the 34465A and the 6500 would have likely been more than sufficient for my needs. On the 34465A, for example, I can get to roughly 1 milliohm with some good confidence. My experience with 4 wire resistance measurements is that in addition to the kelvin clips and the DMM itself, the room temperature is going to need to be controlled pretty tightly if you want to successfully measure to a milliohm or maybe to 100s of microohms. I made a bunch of simple 4 wire resistance tests that I posted on the forum if you are interested.For me, the basic measuring functionality, precision and accuracy, ease of use, reliability, and KS support were the main drivers but I think all of those would probably be good with 6500 too - with the touch screen being an unknown/TBD for me as a first time bench top DMM user, but again, I suspect the touch screen would turn out to have both some negatives and some positives.What I think would have tipped me toward the 6500 was if I was more inclined to dive deeply into the software functionality of the 6500. I think for someone who is reasonably to highly adept with software the 6500 would be an outstanding unit. The only other unknown for me was the occasional report of 6500 bugs. I think with all the 6500 software flexibility you might have to wrestle a machine that starts to feel a bit like a computer, but again, if you are strong with software maybe no problem, as in no pain no gain. I'm sure it would be nice to have both the 34465A and the 6500.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2022, 09:06:28 am
content: At the very low ohms end it can be relevant what test current is used (3446x use 1 mA, DMM6500 goes upt to 10 mA) and if they offer a offset compensated mode to eliminate the error from thermal EMF. With some resistors the thermal EMF can be quite some problem if the there are temperature gradiends (e.g. hold probes with the hand or not enough waiting after handling).The 1 Ohms range with the DMM6500 looks more like a digital zoom and is likely of very limited value.Much of the DMM6500 SW problems have been resolved to some degree, so many of the initial problems are no longer present.There are already at least 2 other thereads about the KS ACAL problems.

author: HighVoltage
author_rank: Super Contributor
timestamp: March 04, 2022, 09:29:46 am
content: Quote from: Kleinstein on March 04, 2022, 09:06:28 amThe low ohm feature of the DMM6500 is much better than one would expect.As I have said in other threads before, both instruments are great.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2022, 09:48:45 am
content: Quote from: HighVoltage on March 04, 2022, 09:29:46 amLow ohms is good, but the 1 Ohms range would be 10 mV max for the measured voltage and I don't think there is a real 10 mV range, more like just a digital x 10.The 10 Ohms range with 10 mA test current is already good - though 10 mA with up to 12 V could be a problem for some tiny resistors / transistors.

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 04, 2022, 10:54:32 am
content: Quote from: blackdog on March 03, 2022, 11:23:08 amHello Bram,I also have the 3458A, the 34401A and bought the 34465A in 2015 as an improved version to the latter.I already identified several bugs around the ACAL and calibration functions, which went into two improved FW versions.I also can confirm your observation, that meanwhile after an ACAL a 10Vdc measurement drifts about -1ppm before stabilizing.. this did not happen when the instrument was new. But I find that you have totally exaggerated expectations on your 34465A, and you know that yourself, I assume.This instrument is neither intended, nor specified to make precision measurement below 13ppm stability (24h spec), in contrast to the 3458A.We both know, that it performs better than specified. E.g. my unit is still inside 1y spec. in most of the modes, although I experimented and modified a lot on my instrument.The ACAL function does of course not work like the one in the 3458A, that was also never promoted that way.It only corrects for T.C. effects, and that really works very well, of course inside its specification limits.I did such temperature tests several times, easy in winter time, i.e. let it cool outside, power on inside directly, and attach a 10V reference. Initial reading will be far off, still in spec though, by including T.C. of course, but after ACAL, it will display within 5ppm or so, I don't remember exactly. Repeat that ACAL during warm up, it'll still always be below spec. limits. That also works at elevated room temperatures, like in my bureau, instead in my basement lab which has R.T. = 22 +/-1°C over the year. I also can't confirm that the 34465A needs 12hours for stabilization, it's warmed up after 2h.For the other DMMs I have no experience at all, but I suggest to make fair comparisons based on the specifications only: Do they really perform better than the 344465A for such parameters?In this context, the relevant features why I bought the 34465A are: Offset Compensation for Ohm modes, long term data acquisition and digitizing modes, low DCI ranges (pA resolution), temperature measurement, and other useful features compared to the 344401A. So I also recommend to buy the 34465A, but get the MEM option for free, because that is needed for proper use of the built in DIG function.Frank

author: Traceless
author_rank: Frequent Contributor
timestamp: March 04, 2022, 11:06:19 am
content: Quote from: Dr. Frank on March 04, 2022, 10:54:32 amYou can get that for free? I checked and that seems to be sold as an 250€ upgrade.

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 04, 2022, 12:16:11 pm
content: Quote from: Traceless on March 04, 2022, 11:06:19 amI had to buy both options at that time, plus the GPIB interface.The DIG option is included since FW 3.0.KS offered the MEM option for free several times over the last years as a sales deal, so you have to look out, also on the American site, or ask your German distributor, if they can offer that for free, if you buy the instrument.PS: Currently they include BenchView for free (forget it!), so maybe you can deal-in this for the MEM option.Maybe the other colleagues can tell something about the Keithley SW in comparison?Frank

author: HighVoltage
author_rank: Super Contributor
timestamp: March 04, 2022, 01:21:53 pm
content: Quote from: Kleinstein on March 04, 2022, 09:48:45 amWell, one would always use a milli ohm meter or instrument that is used for low ohm measurements.However, I was really surprised how spot on the DMM6500 is in low ohm measurements.And this experiment can be repeated with success, the instrument really shines here unexpectedly.

author: HighVoltage
author_rank: Super Contributor
timestamp: March 04, 2022, 01:31:00 pm
content: Quote from: Dr. Frank on March 04, 2022, 10:54:32 amI had the horrible ACAL drift experiences with the 34470A and that was never really fixed by Keysight.The ACAL drift of the 34465A is not bad in comparison.Here is the ACAL drift test of my 34465A from 2018.

author: nctnico
author_rank: Super Contributor
timestamp: March 04, 2022, 02:22:07 pm
content: Quote from: HighVoltage on March 04, 2022, 01:21:53 pmYes. But it is nicer if you have instruments that can at least help you out when in a pinch. In my case I suddenly needed to measure a resistor in the range of 500 micro-Ohm with 1% accuracy. A 100 Ohm range is not doing much good in such a case.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 04, 2022, 05:49:09 pm
content: @nctnico, @HighVoltage: I was about to pull the trigger on the 34465A but due to your comments, the positive things reported before and another video (link below) someone sent me via DM I'm reconsidering the DMM 6500 now. The video is german but showed at least two occasions where the DMM 6500 was clearly superior to a 34461A. I doubt though that the test results would have looked different on a 34465A:1. at 7:03 the peak-to-peak current while switching on a light bulb is measured. Due to the super high sampling rate the Keithley caught the inrush current, which was missed by the Keysight.2. 8:04 Because of the larger display and zoom the Keithley can display even weak signals that show as flat line on the 34461A. The Keithley also seems to offer higher resolutions on the time axis.

author: mawyatt
author_rank: Super Contributor
timestamp: March 04, 2022, 05:55:15 pm
content: We did a couple quick low ohms Kelvin (0.1 & 1 Dale 1% Chassis mount type) measurements 1/27 and 2/4 with a 2 year old and new KS3465A, a 6 month old DMM6500 and a 8 month old Tonghui TH2830 LCR meter. All meters used cheap Kelvin probes for measurements of low ohms (TH use supplied Kelvin probes), the 1 ohm resistor all readings agreed under ~1000ppm, 0.1 ohms under ~7000ppm. Repeatability from two dates was; older KS 5000/288, new KS 6300/400, DMM 2300/262, TH was 1900ppm/90ppm for 0.1 and 1 ohms respectively. No attempt was made to record the setup, temp or exact probes used, so variations were highly likely between dates.Anyway YMMV,Best

author: Kleinstein
author_rank: Super Contributor
timestamp: March 04, 2022, 06:54:35 pm
content: In that German video they just used a wrong PLC setting to do the peak current test. With a more reasonable setting the 34461 would have been done better and OK for the lamp. The 34465 is faster, than the 34461, though still not as fast as the 2nd ADC in the conversion rate as the DMM6500. However the DMM6500 has a limited BW (in some ranges relatively slow) and thus can not make full use of the high sampling speed of the 2nd ADC (digitizer mode). The faster ADC also has limited accuracy. At least the 2nd ADC allows a good digital AC mode.The screen resolution is a bit limited for the KS meters and thus the somewhat limited screen shots.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 04, 2022, 08:01:16 pm
content: Quote from: Kleinstein on March 04, 2022, 06:54:35 pmI see, thanks for clarifying that.

author: Electro Fan
author_rank: Super Contributor
timestamp: March 04, 2022, 09:13:42 pm
content: Traceless, some more considerations for your decision.Regarding capacitance which you mentioned in your original post, if you don't already have a LCR meter, the DER DE-5000 is an excellent meter that won't add a lot of expense on top of either a 34465A or a 6500. It's always good to have a second device that can help you gauge the sanity if not the accuracy and precision of another device's measurements and the DE-5000 not only give you some reasonable accuracy, it will also measure some values that neither of the bench meters will measure.If you can get the extra memory for the 34465A at no extra charge (if KS happens to be running the special or if you can persuade them or a distributor to throw it in) that would of course be good. Having said that some considerations: 1) I think you can add the memory later. 2) with the standard memory you can still do a lot; I ran a test for about a week (probably more than most tests will need) with the standard 50k readings memory:https://www.eevblog.com/forum/testgear/4-wire-2-wire-resistance-tests-various-cheap-kelvin-clips-various-meters/msg3256942/#msg3256942And 3) if you have to pay 250€ or so for the extra memory that should be more than enough to buy a DE-5000.Having said all that, I'm just an enthusiast and there are some much more experienced and capable folks here that can give you more insight on the details and the tradeoffs.

author: blackdog
author_rank: Frequent Contributor
timestamp: March 04, 2022, 10:14:57 pm
content: Hi Frank,Autocal 34465aMy expectations of the 34465A was that the Autocal worked well at the 10V DC range and that is what you also point out, was not executed properly bij Keysight and I do blame Keysight for that, do it right or don't do it.The autocal is usable, do an autocal read within 15 seconds(and withmy34465a it is within 1PPM on 10V DC range)As I mentioned, I am certainly happy with the filter operation that is available as an extra in the 34465a, also the extra possibilities for temperature measurements are appreciated, and the 34465a is used here almost daily.This is because in temperature measurements with the TEK DMM4050 with a resolution of 0.001C there is a lot of noise present and the 34465a has the extra filter and less noise.34465a VS 3458aAs you yourself pointed out I am aware that it is not a 3458a.My two Keysigt 34461a are still within specs as far as DC is concerned and my two 34461a meters drift on the DC 10V range no more than 3 to 5PPM / year, and that is very good.34401aEven my 34401a after 8 years is still within 6PPM the specified value of course around the calibration temperature.The 34401a is a bit more sensitive to ambient temperature variation, this for the meter I have here, I have no knowledge of other meters of this model.ConsiderationsIf you don't think the interface is very important, then I would choose the Keithley 6500 over the 34461a.But this is based on 1x Keithley 6500 and I have had 5 pieces of 3446x in here.But 6500 VS 34465a everyone has to decide for themselves, my measuring sessions are certainly different from yours.ServiceThe Service I have had from Keysight has been excellent, Service from Keithley I have fortunately not needed yet.The 6500 is now almost three months old and as far as I have figured out, very stable.Kind regards,Bram

author: Henry Finley
author_rank: Regular Contributor
timestamp: March 05, 2022, 05:34:12 am
content: Frakly I think we've past the point of diminishing returns on much gear. And one thing I can be sure of is that China is not contributory to advancement aside of what they can appropriate the proceeds of, for their own purposes. And since most factory labor in the US is by refugees, expensive, and not even as wll made anyway then what's the point in frittering good money after bad? In concludion, if an old HP US-made machine still works quite well, why do I need all that crap foreign made (and often counterfeit). junk. As in JUNQUE, junk. From what I've seen, Mr Carlson seems to come up with some fine pieces of gear, available for us to fabricate for ourselves. There are 40 ways to test a cap. but if you are testing the cap because you suspect it, then wouln't just replacing it and seeing, be a better use of time?

author: tautech
author_rank: Super Contributor
timestamp: March 05, 2022, 05:40:40 am
content: Quote from: Henry Finley on March 05, 2022, 05:34:12 amTake that anti China crap elsewhere please.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 05, 2022, 08:29:27 am
content: Quote from: Electro Fan on March 04, 2022, 09:13:42 pmI've seen and read quite a lot of good things about the DER DE-5000. I already own an LCR Meter, the DER DE-5000 was one of the candidates I considered but ultimately went with the5200model from Matrix.Quote from: Electro Fan on March 04, 2022, 09:13:42 pmQuote from: Dr. Frank on March 04, 2022, 12:16:11 pmThank you Dr. Frank and Electro Fan, I actually found out that theKeysight Memory Promotionis currently available. What is not clear (yet) is if I had to purchase through KS directly to qualify.Quote from: tautech on March 03, 2022, 10:04:49 pmIt took me a bit of time to find out if/how to get a DMM Check here. Ordering directly from abroad involves considerable import fees, but it seems there is a german distributor assumingthisis the DMM check you are talking about. Unfortunately the model with LC option is marked "out of supply".Also thank you @tautech for pointing out the resource on Defpom's site.Quote from: tautech on March 03, 2022, 10:04:49 pmI'm trying to stay away from it, it is tempting though

author: tautech
author_rank: Super Contributor
timestamp: March 05, 2022, 08:39:05 am
content: Quote from: Traceless on March 05, 2022, 08:29:27 amYep, there's also thread about them here IIRC and I think it is Doug that makes them:https://dmmcheckplus.com/Quote from: Traceless on March 05, 2022, 08:29:27 amNo worries, enjoy the voyage.

author: Dr. Frank
author_rank: Super Contributor
timestamp: March 05, 2022, 10:53:27 am
content: Quote from: Traceless on March 04, 2022, 05:49:09 pmPlease do not follow such completely incompetent videos or sites!These guys have obviously no clue what they are talking about, and in this case did not inform themselves at all about the KS instruments. I can only say: RTFM and RTFSIf a shorter sampling time had been used on the '461, 300µs is the fastest, instead of this NPLC 10, i.e. 200ms, as done on the Keithley DMM, then of course it would have caught the peak inrush current.The 34465A of course is even faster than the '461, using its digitizing feature for DCV and DCI, which samples down to 20µs timely resolution. So yes this model is of course able to catch the inrush current also graphically and resolving it like the Keithley one, by simply using its button based ZOOM functions for time and volt axis.That woman was simply not competent to use the KS correctly, and evidently she did not make herself familiar with it, neither with it's manual or specification.Another hint: I regard the DMMcheck as a toy only, as you can't really calibrate DMMs as it's got a few single ranges only.So if you have the demand to check some of your other equipment, then either buy such a 6.5 digit DMM, or ask the volt-nuts community here in Germany, they are located all over the place, and all might give a practical help, w/o expecting you to become a volt-nut also. But you're of course very welcome, otherwise.Frank

author: Traceless
author_rank: Frequent Contributor
timestamp: March 05, 2022, 12:17:54 pm
content: Quote from: Dr. Frank on March 05, 2022, 10:53:27 am@Dr. Frank: Of course I take every information I find, espacially stuff on youtube, with a grain of salt. Luckily there is this awesome community which helps to identify such mistakes. Thank you for confirming that the 34465A can very well keep up with the DMM 6500 for those test cases.@Everyone: I still have a few final questions, that may affect the purchase decision. Maybe the folks that have long-ish term experience with 34465A and the DMM-6500, can comment on some of them:Software/autocal issues aside, Are there any known weaknesses in any of the units (34465A, DMM 6500)? Example of issues that come to mind: Buttons not working properly/touchscreen becoming unesponsive after some time of use, input jacks wearing down fast or even breaking, issues with the power supply, fan bearings etc.How easy/hard is it to replace fuses, input jacks, fans? Are spare parts even available to "regular mortals" and is there a significant difference in sparpart prices between Keithley/Keysight?How well are the devices protected against a catastrophically misbehaving device under test (e.g. like the PSU shown in the video below)?Can I upgrade every option available for the devices after purchase or are there certain add-ons that can only be ordered with a new unit. (For instance the Siglent SDM3065X apparently can not be upgraded with a scanner card, instead one needs to purchase an SDM 3065XSCinstead).Does any of the meters provide serious additonal value in terms of accessories. The A34465A comes with a "34138A test leads set", which I assume is decent. However if I'm not mistaken non of the meters comes with kelvin leads for 4-wire measurement. Looking for kelvin leads revealed they cost north of 450€ a pair on mouser (Are these made out of iridium threads handwoven by disney princesses, or what is going on here?). A more affordable pair from BK Precision (TLDK1) is available for ~100€, which still is a bit steep just for a set of leads.Does the DM-6500 come with a stylus?

author: nctnico
author_rank: Super Contributor
timestamp: March 05, 2022, 12:58:17 pm
content: In my opinion you shouldn't care so much about repairs / spare parts. The bench DMMs discussed are high quality gear and will last a long time. The only fuse you can blow is the one for the current measurement and that is externally accessible. Other than that, the inputs are very rugged. Still, I wouldn't use a high end bench DMM like this on mains with all the nasty spikes that can ride on top of it.

author: Kleinstein
author_rank: Super Contributor
timestamp: March 05, 2022, 01:39:29 pm
content: There are some complaints about the view angle on some of the meters. This is somewhat normal lmitiation with many LCDs as a larger viewing angle needs more power. AFAIR the angle on the 6500 is a bit limited.For the DMM6500 there may be the option to install a scanner card (original and some plans around for a DIY solution).Some early DMM6500 had roblems with transformer hum, but this problem should be fixed for newer units.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 05, 2022, 01:59:31 pm
content: @nctnico: I'd also rather keep the DMM away from dangerous stuff, but for me there is a catch here. As mentioned in the beginning of this thread the DMM I'm about to purchase is going to be the "swiss army knife" of my lab. As such it should (and has to) do basically everything well that includes PSU diagnosis. The alternative would be to use my Aneng 8009 for primary side PSU work. I also have two more handheldsvery similar to these, which are cheap to replace, probably even cheaper then the fuse on a 34465A or the DMM-6500. Also they make mains work a lot more "exciting", but usually I try to keep the excitement level to a minimum during mains work.@Kleinstein: Viewing angles are also a good point, thanks for bringing that up. Nice to hear that Keithley actually improves their devices if stuff like the transformer hum is discovered.

author: mawyatt
author_rank: Super Contributor
timestamp: March 05, 2022, 05:34:42 pm
content: @Traceless,Think you have only one option, that's get both the KS and DMM and decide for yourselfI'll wager a brew that you'll end up keeping bothBTW Dr Frank is one of thevery veryfew I always listen too, never a hint of misinformationAlso, are you going to do an evaluation of the new 5200, maybe a peek insideThe DE-5000 use a special chip set that does all the heavy lifting, and does so very well indeed as various tests have shown (ours compares very well with the TH2830, in fact so good we are preparing adapters to allow all the Tonghui fixtures to work with DE-5000).Best

author: Electro Fan
author_rank: Super Contributor
timestamp: March 05, 2022, 06:24:58 pm
content: +1 for ^ what mawyatt says ^

author: Traceless
author_rank: Frequent Contributor
timestamp: March 05, 2022, 06:32:36 pm
content: Quote from: mawyatt on March 05, 2022, 05:34:42 pmQuote from: Electro Fan on March 05, 2022, 06:24:58 pmI have to admit that thought crossed my mind for a split second, then I remembered what Mrs. Traceless would say about that:Quote from: mawyatt on March 05, 2022, 05:34:42 pmI'll keep that in mind also many thanks to Dr. Frank for being such an awesome source of information.Quote from: mawyatt on March 05, 2022, 05:34:42 pmTony was actually faster than me and did a very detailed full review including a look inside (link below). I can confirm it is a very nice unit, very good build quality, highly accurate. If you have any questions Tony didn't cover I'll gladly try to answer them to the best of my abilities.Here is Tony's MCR 5200 sneak peek (he's going to open it about 17 minutes into the video):

author: exmadscientist
author_rank: Frequent Contributor
timestamp: March 05, 2022, 10:09:32 pm
content: Quote from: mawyatt on March 05, 2022, 05:34:42 pmSo we did this! Turns out both are pretty much interchangeable, so get whichever one you want. There may be minutely better specs on any given range for one meter, but they're close enough that I forgot which is which.The 34465A is distinctly easier to take a quick measurement with. Somehow it always gets grabbed first if both meters are available on the shelf, and I think this is why.The DMM6500's triggering system is far more powerful. You can do some really amazing things with it! Unfortunately, by the time you learn/remember how to use it, you'll probably be dead of old age. The graphing is similar. The little front and rear fuseholders are nice to have, I wish more instruments were done that way. This is objectively the "better" meter, thanks to that triggering system, but it seems to be most people's second choice.As for faults, we've found a couple. The DMM6500 UI can crash. Not often, but it can. It doesn't always handle SCPI commands well, occasionally and repeatably barfing out weird errors it's not supposed to (and that the 34465A doesn't choke on). The 34465A, for its part, seems to have some isolation/leakage issues. But take that with a grain of salt, it was being used in a setup that seems to reliably get annoyed with even nA of leakage to earth. (We didn't try the DMM6500 there. Actually, we didn't really want to continue troubleshooting that problem at all.)So, yeah. Get whichever one strikes your fancy, you won't regret it.Though if you do get the 3446x, set the display background to black instead of blue... you'll thank me later.

author: Hydron
author_rank: Super Contributor
timestamp: March 06, 2022, 12:52:05 am
content: How long does the 34465A take to boot btw? I was choosing between the DMM6500 and the 34461A last year, and the eternity it seemed to take the 61A to boot in videos I saw online was a factor in going for the 6500 (it was also cheaper and had more features, and I'm glad I avoided KS in the end given their horrible and possibly illegal new attitude towards supporting private customers!)I know that you should leave a meter warmed up for best accuracy, but you mentioned "take a quick measurement with". Probably a good excuse to have something like a 34401A/34410A floating about too, that's 3 meters now

author: Cerebus
author_rank: Super Contributor
timestamp: March 06, 2022, 01:22:15 am
content: Just timed my 34461A at 27 seconds from hitting the power button to the first measurement appearing. I doubt that they 34465A is much, if any different.If you're waiting for it, it seems like an age. If you remember to turn it onbeforegoing to get appropriate test leads off the rack then it's generally ready by the time you are ready to plug them in.

author: mawyatt
author_rank: Super Contributor
timestamp: March 06, 2022, 02:20:20 am
content: 29 seconds for KS34465A.Best,

author: jjoonathan
author_rank: Frequent Contributor
timestamp: March 06, 2022, 02:40:44 am
content: DMM7510 -- 13 secondsVrooom! (At least by the standards of modern "needs an OS" instruments)

author: Traceless
author_rank: Frequent Contributor
timestamp: March 06, 2022, 11:00:19 am
content: Quote from: exmadscientist on March 05, 2022, 10:09:32 pmI guess that is the "familiarity factor" the Keysight has going for it. The UI just works the way everyone expects a multimeter to work, just from past experience. The DMM 6500 UI may even be more convenient and more intuitive to use especially when it comes to more advanced funtions, but it is very different so users don't feel immediately at home. Once one gets past that prejudice and the two major disadvantages of touch screens (namely dirty screen/fingerprits, no tactile feedback) I'm sure the DMM 6500 will be a very pleasant user experience.Quote from: exmadscientist on March 05, 2022, 10:09:32 pmConsidering my lab is not an ideal test environment I'd wager that setups that sensitive would be infeasible for me anyways.Quote from: exmadscientist on March 05, 2022, 10:09:32 pmI'll keep that in mind thanks =)Quote from: Hydron on March 06, 2022, 12:52:05 amYes Idefinitlydislike this attitude and that was one of the main reasons I started this discussion. One positive thing I can report in this regard: I contacted Keysight because of the free deep memory upgrade mentioned by Dr. Frank and Electro Fan earlier in this thread. The folks at Keysight were friendly and helpful so far and promised to inform me if/how that promotion can be used in case the meter is not directly purchased through their B2B distributors. Also others have mentioned that Keysight support would be great, so maybe things are different in Europe and the US?Quote from: Hydron on March 06, 2022, 12:52:05 amThe temptation is definitly there but the bench is getting crammed already, if I give in to the dark side there will be zero space left to do actual work, because everything is occupied by test gear and I'll utimately have to sign up with TEA@Cerebus, @mawyatt: Thanks for measuring, they really seem to have sped up the boot on the Keysight significantly. I was expecting worse. When Dave reviewed the Agilent 34461A it took around a minute to boot.@jjoonathan: That is quick, so a plus for the DMM 6500 here.

author: Hydron
author_rank: Super Contributor
timestamp: March 06, 2022, 12:34:30 pm
content: Just timed my DMM6500 as being between 16 and 17 seconds, so a little slower than the 7.5 digit version, but still significantly faster the KS (which I also though was a minute or so, which was pretty unacceptable, good to see it's now a bit quicker - did they change the OS or something due to winCE being canned by MS?)My R&S scope is still the winner out in the "needs an OS" category at ~10 seconds - I wish more manufacturers would prioritise boot time. Then again, my ancient analogue-only tek current probe/amp are the clear losers in this race - if you're doing any sensitive work in DC coupled mode you have to give it a good half hour to warm up and stop drifting!I'm pretty happy with my choice of DMM6500 btw - it's not perfect, but neither is the KS, and they have their own strengths and weaknesses.

author: Traceless
author_rank: Frequent Contributor
timestamp: March 06, 2022, 12:49:08 pm
content: Quote from: Hydron on March 06, 2022, 12:34:30 pmTo be honest I'm not reallythatworried about boot time. Usually when I go to my bench the first two steps are: 1. turn on DMM and 2. start my bench PC (which probably also takes something like 30s to boot up). So till I set up the DUT got all tools and stuff both devices will have booted. And as you said - if one really wants to do things properly the DMM should warm up for a lot longer than a minute. At that point boot time becomes negligible.Quote from: Hydron on March 06, 2022, 12:34:30 pmSince you own the DMM 6500 - did yours come with a stylus? I tried to find a list of accessories in some online shops and the manual but didn't find any details.

author: Hydron
author_rank: Super Contributor
timestamp: March 06, 2022, 01:14:48 pm
content: No stylus, but I've never missed one - the only gloves I ever use are thin nitrile so they work without issue. The UI is also designed for touch use so no elements too small to hit reliably with a fat finger.Quick list of pros/cons of the 6500 if it helps:Pros:- was quite a bit cheaper here (UK) than KS equivalents (and I'm talking '61A, not even '65A!)- fast digitisation, complex trigger options etc- low ohms range is very sensitive (1uOhm resolution!)- good sized screen, touch UI is reasonably well done, great for entering numerical parameters etc too- can do great graphs etc, lots of memory for long logging sessions- remote web UI etc (apparently KS's is/was some shit java thing)- no KS professional-use-only bullshit. Would have been a con for higher Tek calibration cost but you can't even get one from KS anymore!- scanner card option, including building custom DIY ones- can run custom scripts, apps etc (though see below)- no option keys needed for features - base model is the only model, with everything enabled- reasonably fast boot timeCons:- no hard power switch, is a soft one and draws a few watts in standby- screen viewing angle could be better (never unusable, just gets a little washed out)- buying one supports Danaher (though I'd not want to support KS's new business model right now either)- no direct buttons to change measurement function- ohms mode can choke on inductive elements like transformer windings (v. annoying if you're measuring these regularly)- deeper than KS unit (partly due to scanner option, so not a big criticism)- some early units have transformer hum (as an ex-demo unit built in 2019 mine did, but Tek fixed it)- 10A jack is rear terminals only- app support is pretty much alpha-only, expect bugs (never had any major bug issues in normal use though)- Tek currently are charging for their PC software, though I'd be unlikely to use it anyway

author: Traceless
author_rank: Frequent Contributor
timestamp: March 06, 2022, 01:47:13 pm
content: @Hydron: Thanks for the awesome pros/cons list. It seems there are some styluses available for around 10 bucks, they are made for tablets but I guess they'll work fine for the DMM 6500.I'm actually really surprised that so many here report they are either wearing thin nitril gloves or mostly no gloves at all. Personally I wear them mostly as cut/scratch protecton and to reduce skin contact with chemicals. However given the attention that is payed to position DMMs not next to other devices to minimize interferences, keeping ambient temperature constant, heating instruments up twisting DMM leads etc. I'd really have expected more here to wear "proper" gloves in order to reduce influence of body temperature on the probes. The human body temperature is way more than 10°C over lab ambient temperature. So the probes will warm up while you hold them and cool down while you put them on the bench. Normally I'd say it doesn't matter but within the super sensitive experiments some described here before it might do.

author: mawyatt
author_rank: Super Contributor
timestamp: March 06, 2022, 02:22:25 pm
content: Having and using both the KS and DMM, the KS is always the easier to "goto" for just simple quick measurement for use. The DMM touch screen is time consuming to navigate, the KS wins hands down for initial ease of use. If even quicker measurements are required then the Fluke 87 or a couple 34401As are available (boot time <2s!!).Regarding sensitive measurements, generally these should be performed without hand intervention or holding... this is what a variety of DMM probes with clip-on capability are for.Best,

author: Cerebus
author_rank: Super Contributor
timestamp: March 06, 2022, 03:24:19 pm
content: Quote from: Traceless on March 06, 2022, 11:00:19 amIt's that slow Australian electricity, the heat makes it sluggish at getting out of the wires.The firmware version on mine is A.03.00-02.40-03.00-00.52-01-01. Probably more recent than Dave's example, but also not the most recent.That actually brings me to another point. I found the software update process a bit iffy, I had to have several goes at updating mine and was in mortal fear that I'd bricked the thing at one point when it went unresponsive and had to be power cycled. Which is why I haven't yet got around to installing the latest firmware, I'm a little nervous of doing so. (I've actually just downloaded the latest firmware, so wish me luck.)

author: Traceless
author_rank: Frequent Contributor
timestamp: March 06, 2022, 03:37:47 pm
content: Quote from: Cerebus on March 06, 2022, 03:24:19 pmThe poor electrons have to move upside down all day, i guess they just get nauseus - still good enough for austrailaQuote from: Cerebus on March 06, 2022, 03:24:19 pmWhat is the firmware stored on? Any chance to reprogram it using a TL866 or a CH341A?

author: Cerebus
author_rank: Super Contributor
timestamp: March 06, 2022, 03:41:57 pm
content: Quote from: Traceless on March 06, 2022, 03:37:47 pmInternally? No idea. You just chuck the supplied firmware onto a USB stick and select firmware upgrade from the utility menu.Upgraded to A.03.03 successfully and with no fuss, and now it take 29 seconds to boot, a whole 2 seconds longer than on the previous version I had on there.

author: mawyatt
author_rank: Super Contributor
timestamp: March 06, 2022, 03:45:22 pm
content: Regarding Keysight CS, they haven't responded yet to an issue with the Web sever, and we have two doing the same thing. Everything else with Web servers works fine, just the KS34465As don'tBest,

author: tautech
author_rank: Super Contributor
timestamp: March 06, 2022, 07:29:12 pm
content: Quote from: Cerebus on March 06, 2022, 03:41:57 pmFirst boot after upgrade or those thereafter ?I'm normally seeing first boot slower than normal after which the OS has its shit together with the new FW and back to normal with subsequent boots.

author: Cerebus
author_rank: Super Contributor
timestamp: March 06, 2022, 08:06:16 pm
content: Quote from: tautech on March 06, 2022, 07:29:12 pmI've been in this game too long to get caught out like that. 2nd boot, after it was all done, and dusted. Rebooted another time (after the reboot that's automatic during the firmware upgrade) to be sure that it had taken the update cleanly and then powered off again then rebooted to time it. It agrees precisely with mawyatt's 29 second boot which is what I'd expect (assuming that he was up to date on firmware whereas I most definitely was not).

author: tautech
author_rank: Super Contributor
timestamp: March 06, 2022, 09:02:38 pm
content: Quote from: Cerebus on March 06, 2022, 08:06:16 pmYes we see first the boot taking longer than subsequent other than FW updates. Not ideal when this is the new owners first impression of their new instrument but sadly too few dealers go the the effort we do checking for FW updates and getting that first boot outta the way before shipping any instrument out.First impressions count !

author: Traceless
author_rank: Frequent Contributor
timestamp: March 07, 2022, 07:51:44 am
content: Quote from: mawyatt on March 06, 2022, 03:45:22 pmIn case I get the KS I could try if I can replicate the problem, can you tell what that symptoms are?@Everyone: Yesterday I looked at the manuals of both the 34465A and the DMM 6500 and stumbled upon another disadvantage of the 34465A and just wanted to add that to the list of pros/cons: There is no way to set continuity mode thresholds on the 34465A,it is fixed at 10 Ohms(c.f. page 21). Below the threshold you get a beep, but if resistance is higher the meter just displays the resistance (of up to 1kOhm). The DMM 6500 lets you fully customize that.

author: blackdog
author_rank: Frequent Contributor
timestamp: March 07, 2022, 09:41:09 am
content: Hi,ContinuityThe continuity works well on the 3446xa DMM these days., I almost never use the continuity functionA much more important point for the use of this function are the measuring probes you get with most multimeters, these are just not good...The contact resistance is too high due to the oxidation process and therefore the continuity does not work properly and of course also the resistance measurement in the low values works therefore unreliable.Here a picture of a set of probes that are good but there are of course more brands that are good, but the probes from Fluke, TEK, Keysight are not comparable with the Bryman B.T.C. probes that I have here.And no they are not perfect, this due to use the layer of gold wears off the tip, but at other points of the probe tip it is still good, as is the unscrewable part which is very handy..Display colorYes, make the background black is a good tip.Webinterface 34465aI don't recall encountering any problems with this, but also haven't used this feature much.Boot timeMost of the time this is not important, because you already know you are going to measure something before you need the DMM, just turn it on before you really want to measure.the Keysight 3446xa series is usually well within its specification within 30 minutes.But most measurements that will be done can be done with a 3.5 Digit DMM.But that of course varies by user, more usually that will be correct for hobby use.10-Ampere rangeThis large current range is hardly used by me.When I do start measuring large currents, I take a hand DMM for that, but not everyone has that available.Low resistance valuesYou can attach a lot of value to the function, but be aware that accurately measuring low resistance values is not easy.This is also the case with 4-wire measurements, and you can only do that with 4-wire measurement method!Mr. Seebeck is around every corner!Kind regards,Bram

author: mawyatt
author_rank: Super Contributor
timestamp: March 07, 2022, 02:17:23 pm
content: Quote from: Traceless on March 07, 2022, 07:51:44 amHere.https://www.eevblog.com/forum/testgear/web-issue-with-ks34465a/msg4032790/#msg4032790Best,

author: blackdog
author_rank: Frequent Contributor
timestamp: March 07, 2022, 03:43:15 pm
content: Hi mawyatt,Based on the link you showed, something comes to mind that occurred with my 34465a DMM.I was testing about half a year ago with a piece of software in my LAN to "wake up" computers, which for those who don't know is called W.O.L, Wake On Lan.When I tried to wake up different computers to their M.A.C. address, the 34465a crashed.There was no IP conflict in my LAN, so see if you are sending WOL packets within your network segment.I hope this helps.Kind regards,Bram

author: mawyatt
author_rank: Super Contributor
timestamp: March 07, 2022, 04:18:11 pm
content: Hi Bram,I've disconnected everything for the network and just tried to use the Web Server. I can get to the KS34465A, but have to try a couple times, can ping it and get good results, KS LAN Status on KS indicates Good. However the mentioned error message (Application Error.....) appears on the KS screen in a window and can't be removed, but not on the Web Server screen at my computer. Can't figure out how to remove it on the KS screen without recycling power.This is the same result as when other devices are connected to network and they all work without any errors or error messages, so very annoying!!Keysight has provided no support so far, par for what others have indicated. We have a small 3 person research company, Wyatt Labs LLC, employees are me, myself and IBest,

author: Cerebus
author_rank: Super Contributor
timestamp: March 07, 2022, 04:33:52 pm
content: Quote from: mawyatt on March 07, 2022, 04:18:11 pmI'm going to follow this up over in the existing thread (https://www.eevblog.com/forum/testgear/web-issue-with-ks34465a/msg4032790/#msg4032790) to avoid sidetracking this thread more.

author: Domitronic
author_rank: Regular Contributor
timestamp: March 07, 2022, 07:49:44 pm
content: Quote from: Hydron on March 06, 2022, 01:14:48 pmIt is Fortive now. Was spun off from Danaher 5 or 6 years ago.

author: pope
author_rank: Frequent Contributor
timestamp: May 21, 2022, 04:19:07 pm
content: Quote from: Traceless on March 02, 2022, 12:32:19 amSorry for the off-topic but how do you like the mcr-5200?

author: Joop01
author_rank: Contributor
timestamp: June 17, 2023, 09:18:27 pm
content: Quote from: Traceless on March 02, 2022, 08:09:35 pmI'm busy with my choice. I do audio, so ACV or better said the standard 0.775V or the reference 0dBu. The Siglent SDM 3065X has in the end an error of +/-0,16% for measuring 0.775V. The Gw-Instek GDM-9061 has a calculated error of +/- 0,10% for measuring 0.775V. The difference has much to do with the range you have to use. With Siglent this is 2 Volt and with Gw-Instek it is 1 Volt. So counts does not say it all.

author: 2N3055
author_rank: Super Contributor
timestamp: June 18, 2023, 05:04:58 pm
content: Quote from: Joop01 on June 17, 2023, 09:18:27 pmCould you please be so kind and explain how did you calculate that error for SDM3065X and at what frequency?At 10Hz-20kHz range (where it is best) it has 1 year accuracy of 0.06% of the read value +0.03% of range..I end up with 0,14% for SDM3065 .... and GDM-9061 comes out at 0.1% like you said.Of course that is worst case 1 year spec.. Both will do better in real life.And also while 0dBµ is the reference , if you need to measure 6dBµ, SDM3065 will do that one better...

author: Joop01
author_rank: Contributor
timestamp: June 18, 2023, 08:05:27 pm
content: It is a little better for the SDM 3065X, mixed up two readings, its now 0,14%, but still not the value of the GDM-9061. Yes, took the frequency 10Hz-20kHz. Problem here is that 2.200.000 is not better than 1.200.000. Both have as second digit a "2", a "7" won't fit. So both "2" will be zero and the first "0" will be used for the first "7". So in both dmm's you have 5 figures for the actual measurement. As Siglent has a range of 2 the error for correction of range will also be double. The GwInstek has a range of 1 and does profit in this way because the error for correction of range is only single. Yes, I took 1 year spec (I don't call it worst) because that will be more realistic for the hobbyist. If you want 90days then remember that all calculations has to be done same way. I don't advice 24hours, you never get your instrument 24 hours after calibrating. Nice for advertising. There is an other thing which can be found as "loading errors". GwInstek stays 10MOhm, but the Siglent has with 10kHz already an input resistance of 160kOhm (page 92). This can add up to the total error. Have to work out what it will do with other known audio levels.

author: 2N3055
author_rank: Super Contributor
timestamp: June 18, 2023, 09:41:05 pm
content: Quote from: Joop01 on June 18, 2023, 08:05:27 pmI was just confused by math.. that is all.. Thanks for responding.2.200 000 is not better than 1.200 000 but different. At 0dBµV GW Instek will have slightly better guaranteed accuracy. At 6dBµV it will have to range one range up and will lose a digit.. In which case Siglent will be better..It is highly important where on the scale do you measure. You could do a better job with a 5.5 digit meter in "happy range" than 6.5 digit meter that has to range up..For instance, when measuring 12V car electronics (8 -18V range), meters with 20V range will do better for that range, not to mention, that relative measurements are much more accurate in single range. For relative measurements in single range, you can use 24H specs.As for GW Instek "staying 10 MΩ" are you sure about that?Pure resistive 10 MΩ ?GW Instek Manual states 1MΩ//100pF... that's 157 something kΩ |Z| at 10kHz ..... page 373

author: Joop01
author_rank: Contributor
timestamp: June 19, 2023, 12:13:23 am
content: Quote from: 2N3055 on June 18, 2023, 09:41:05 pmNo, its not in the manual and the one I have does have 368 pages. You have a choice between 10M or 10G, this could mean that they have split the input stage in two, first 10M/10G and in the second stage what you will find normally up front. I seen this more in diy input dividers which show then similar results, but of course this is very speculative.I have to check your remark about 5.5 digit meter, but in my spreadsheet sits also R&S HMC8012 and it has the worst specs. I wanted to know if this meter was better, but its not, the only thing which stays is the double read out with stats. As meters will break you can ask yourself if its wise to settle for special setups which can't be replaced that easily. Thanks for your reply.