Looking for a fast booting bench DMM - Page 1
Forum section: electronics / testgear

author: bateau020
author_rank: Frequent Contributor
timestamp: May 10, 2021, 11:52:52 am
content: hi,looking for a relatively serious bench DMM, my first one. Requirements:fast booting. Less than 10 secs is strongly preferred. Anything more, and I might tend to reach for one of the better handhelds more often, and let the thing gather dust.5.5 digits, maybe 4.5 if nothing suitable can be found. No need for 6 or more.4W resistance meter, 1mOhm resolutionnA resolutiondual display. ACV+DCV at least. If possible DCV+DCIETH or WiFi connectivity. This is a hard requirement.fast continuity test, loud beeplow power consumption, and quietno boat anchor: 30cm depth maxBudget: preferably < 500 EUR. But can be convinced to go up to 1000 EUR if the machine is really nice.And I don't mind hacking a bit to swap out a fan.So I came up with a small list of meters that more or less fit the bill:OWON XDM3051Rigol DM3068 (why do so many people hate the DM3058?)Siglent SDM3055 (but slow booter it seems)Keysight EDU34450AR&S/Hameg HMC8012Any recommendations?

author: balage
author_rank: Regular Contributor
timestamp: May 10, 2021, 02:38:10 pm
content: Hey,Why do you need that fast booting speed? I turn them on once and only turn them off when not using them for a while.EDU34450A has been released a few months ago and I have not heard good things about it.

author: fcb
author_rank: Super Contributor
timestamp: May 10, 2021, 03:25:17 pm
content: Aim-TTI 1908, 5.5 digits for £486 incl UK VAT, so pretty close to your <500EUR.

author: voltsandjolts
author_rank: Unknown
timestamp: May 10, 2021, 03:30:27 pm
content: Quote from: fcb on May 10, 2021, 03:25:17 pmWhere is this price available?I'm considering one of these to replace my handheld.I do 90% bench work, and the 1908 has batteries to cope with the 10% away from bench stuff.

author: fcb
author_rank: Super Contributor
timestamp: May 10, 2021, 04:42:31 pm
content: Farnell, RS listed as distributors on the TTi w/s.https://www.rapidonline.com/aim-tti-1908-5-5-digit-dual-measurement-digital-multimeter-usb-rs232-lxi-85-4887Rapid have it for less, not sure what's going on there. Seem to be quite different prices on RS/FEC - seems that FEC have next day stock available, but at a higher price.Give TTi a bell and ask them for a price. Their customer service has been great in the past.

author: MosherIV
author_rank: Super Contributor
timestamp: May 10, 2021, 05:03:59 pm
content: QuoteIf you want the accuracy of the 5.5 digit, most bench dmm in the 5digit+ field need time for the voltage reference to warm up and stablise. Normally takes at least 1 hour. So fast boot time is pointless.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 10, 2021, 05:47:28 pm
content: Also power consumption isn't important on a bench meter is it?

author: bateau020
author_rank: Frequent Contributor
timestamp: May 10, 2021, 05:58:49 pm
content: Quote from: MosherIV on May 10, 2021, 05:03:59 pmYes, I get that. I just do not need that resolution all the time. Electronics is not my full time job. So the meter will be off most of the time. Sometimes I just want a quick "is this circuit dead" test. 2 digits might even do there. And I'd like that to be available fast. Sometimes I can take my time, and might need more resolution then. I just want 1 tool to cover those use cases. Yes, I have more handheld DMMs than I'd need, but desk space is scarce, especially in this work-from-home period. A bench DMM can help with that.Quote from: BeBuLamar on May 10, 2021, 05:47:28 pmwell, high power consumption generally means fan noise. I would like things to be quiet so I can hear my thoughts.The AIM-TTI 1908P looks really nice, such a shame it only goes down to 100nA, like the HMC8012. Superb dual/triple display capabilities, but this is holding me back from them.

author: PeterKlop
author_rank: Contributor
timestamp: May 10, 2021, 06:46:16 pm
content: GW Instek GDM-9061 (or 9060) boots fast.I bought one a year ago and haven't used it since (life got in the way) but i was nicely suprised by the quick power on when i tested the unit.https://www.gwinstek.com/en-global/products/detail/GDM-906xhttps://www.eleshop.nl/gw-instek-gdm-9061-multimeter.htmlYoutube video:https://youtu.be/-x8Bvjc8yIQ

author: exe
author_rank: Unknown
timestamp: May 10, 2021, 06:51:46 pm
content: I'd myself would love to buy this one:https://www.eevblog.com/forum/testgear/vc8145-thread-it_s-here-finally/. Seems to be a good bench dmm. I'm only hold back by its price, if only it cost $50-70. Paying 180euro for an "empy box" for me a bit hard.My current bench dmm is Keithley K2000. I like it, but it doesn't tick your boxes.I'm also dreaming of a compact version of DMM6500, but that's wishful thinking.

author: Hydron
author_rank: Super Contributor
timestamp: May 10, 2021, 09:14:14 pm
content: Quote from: exe on May 10, 2021, 06:51:46 pmAt least there is some reason for the length (scanner card support, plus commonality of the platform with the DAQ version). They could certainly have shaved off a few cm even with scanner card support if they'd moved the transformer and made a dedicated chassis/PCB though, but it's understandable why they didn't.As for the boot time, the DMM6500 is about 15s - 14s more than I'd prefer, but significantly better than the WinCE KS stuff. When I researched buying a DMM recently the Hameg/R&S HMC8012 sounded like it was probably the quickest modern option - well under 10s. I'd suggest the OP looks at this one again as it seems to meet most of the requirements, and maybe attain the low current resolution in another fashion (e.g. build a DIY feedback ammeter adapter, it's not too hard and you can get pA resolution that way).

author: David Hess
author_rank: Super Contributor
timestamp: May 11, 2021, 12:37:39 am
content: Quote from: bateau020 on May 10, 2021, 11:52:52 amIf taking best advantage of the presumed extra accuracy of a bench multimeter means leaving it turned on, then boot time becomes irrelevant.

author: bdunham7
author_rank: Super Contributor
timestamp: May 11, 2021, 12:49:47 am
content: Look at the BK 5492C. I don't know the boot time and it seems to be 35cm long, but it meets all your other criteria and has a lot of nice features.

author: exe
author_rank: Unknown
timestamp: May 11, 2021, 06:51:20 am
content: Quote from: David Hess on May 11, 2021, 12:37:39 amSometimes I just want to take a quick measurement, then boot time becomes relevant.

author: tautech
author_rank: Super Contributor
timestamp: May 11, 2021, 08:08:16 am
content: SDM3055 boot time is 16s.SDM3045X is same but no fan so sometimes preferred for quiet labs however these have different measuring ranges so datasheets need be compared to ensure which model is the best fit for requirements.

author: David Hess
author_rank: Super Contributor
timestamp: May 11, 2021, 05:11:45 pm
content: Quote from: exe on May 11, 2021, 06:51:20 amWhen I had an HP3478A on my bench which has a relatively fast boot time, I left it turned on during the day anyway. If the meter is left powered on, then there is no boot time.

author: jeffjmr
author_rank: Regular Contributor
timestamp: May 12, 2021, 03:26:16 am
content: My Keithley 2015THD boots in about 4 seconds.Jeff

author: narkeleptk
author_rank: Contributor
timestamp: May 12, 2021, 04:59:13 am
content: I have a tektronix dmm4050. It is pretty nice. You can find good deals on used ones once in awhile. The boot time for power switch is instant long as your leaving the mains switch on. If that is unhooked it takes 30 seconds. Cant say I ever hear fan noise from it, probably fan-less. Its a great meter, all my hand held units are in a drawer somewhere now.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 12, 2021, 04:05:34 pm
content: TEK doesn't make DMM any more. I guess since they belong to the same company that owns Fluke so they leave the DMM and portable scopes business to Fluke.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 12, 2021, 04:17:12 pm
content: The Fluke equivalent (8846A) is sold by official distributors, new, certified and all, at a price (just) lower than second hand machines (in Europe at least). Go figure. Maybe they are planning to replace it or leave the market? It has been on the market since 2006.... But it is a very nice (but pricey) machine indeed.

author: HKJ
author_rank: Super Contributor
timestamp: May 12, 2021, 04:58:37 pm
content: Quote from: bateau020 on May 12, 2021, 04:17:12 pmThe 8846A is dated, all new bench meter uses a graphical color LCD display, not the VFD that ages rather fast. I have two 8846A, one need service, I hope it is a capacitor, but I have not had time to look at it yet. I do not doubt the precision of the 8846A, it is a very precise meter, but it is lacking the features of Keysight 344xxA and Keithley DMMxxxx. I suppose the Keithley meters are the replacement for it.

author: narkeleptk
author_rank: Contributor
timestamp: May 13, 2021, 12:32:15 am
content: Quote from: HKJ on May 12, 2021, 04:58:37 pmI was planning to go with a newer Keithley but found a steal on the 4050 for $500, couldn't resist it at that price.

author: bdunham7
author_rank: Super Contributor
timestamp: May 13, 2021, 11:44:41 pm
content: Quote from: HKJ on May 12, 2021, 04:58:37 pmI wouldn't typically recommend an 8846A to the "which DMM should I buy" crowd, but some of the criticisms of it are overdone or don't take into account the way they are used and abused. I have one and while it has its quirks (it likes to say 'overload' a lot), as a general purpose bench meter it by far outclasses anything else that I've tried.For example, the VFD issue is a a non-issue for the typical hobbyist or solo professional that takes care of their equipment and needs a high quality service bench meter. Although a high-quality TFT display with LED backlighting might be superior, the VFD is better than most lesser quality LCDs or any OLED when it comes to durability and viewability. Sure, I've seen some of these faded (but never failed, so far) but the oldest of these are 15 years old by now and probably have been left on for extended periods at the default (high) brightness. If you use the low or medium setting and turn the display off when you aren't using it, I would expect them to last a very long time. The only ones that last forever are the segmented LED displays, but imagine the whining about datedness if someone came out with those again.As for features, which features? Yes, the newer meters can have graphing ,histograms and so on, but are those the features you want? How about instant on, 1000VAC, 1Gohm, 5V/10V diode with 1.0 and 0.1mA current selection, most ranges and features selectable with one button push, two at the most? Fast continuity with selectable 1/10/100/1000 ohm set points? Accuracy approaching metrology-grade meters along with a very low tempco so it stays accurate in a non-controlled environment? It's definitely a pro model and you pay for it.Now there are downsides. The current measurement setup is a mess if you need precision as good as you would expect from an almost $2K meter without reading the spec sheet. However, the biggest trap is that they are not as internally physically robust nor as serviceable as their 8842A predecessors. I can only recommend the 8846A/DMM4050 for most if you either don't care about money and can just buy a new one, or you score a deal on a mint-condition used one. Buying a used/abused model is a recipe for disaster as broken ones are tough to fix for a variety of reasons. This has caused some people to sour on them, but I have seen no evidence that one of these that is acquired new or mint will give any problems as long as it lives a nice comfortable life. I definitely recommend not dropping them.

author: tooki
author_rank: Super Contributor
timestamp: May 14, 2021, 10:59:57 am
content: Quote from: exe on May 11, 2021, 06:51:20 amYes, we get that. But since bench DMMs are designed for accuracy, and said accuracy necessitates a substantial warm-up period, boot time isn’t a high-priority design requirement. Hence why most bench meters take their time booting up.I have the Keithley 2015, and it boots in just a few seconds (so presumably, its sibling models do, too), and it’s fanless. But it doesn’t have Ethernet or dual display, so out of the running.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 14, 2021, 11:20:11 am
content: I agree! If accuracy isn't important then why use a bench DMM? They don't offer any more functionality than a hand held one except accuracy.

author: HKJ
author_rank: Super Contributor
timestamp: May 14, 2021, 11:26:34 am
content: Quote from: BeBuLamar on May 14, 2021, 11:20:11 amI may have gotten the wrong handheld meters and even believed that I had the most advanced on the market, but none of my handheld meters can match my bench meters in functionality.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 14, 2021, 11:33:10 am
content: .. plus less clutter on the desk. The handhelds tend to get in the way while working on a project. Many desks (mine at least) are always too small.

author: Kleinstein
author_rank: Super Contributor
timestamp: May 14, 2021, 11:44:51 am
content: 4 wire ohms is very rare with handheld meters. Another points is input impedance much higher than 10 M. Most of the other functions can be found with handhelds.Modern DMMs usually do a more or less extensive self test after turn on. This takes it's time as the circuit needs to stabilize first. Especially more modern meters takt the self test more serious, which is normally a good thing. Still faster boot time would be nice and not that difficult. However an OS like Linux with a relatively slow CPU takes it's time.Ethernet or Wifi are 2 rather modern parts, which excludes old meters.

author: HKJ
author_rank: Super Contributor
timestamp: May 14, 2021, 11:50:54 am
content: Quote from: Kleinstein on May 14, 2021, 11:44:51 amNot really, bench meter can sample much faster, show trend charts (A few handhelds support this), histogram and more statistic than handhelds.Handhelds have a higher CAT rating than bench meters and some can do stuff that bench meter cannot do.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 14, 2021, 01:08:59 pm
content: Quote from: Kleinstein on May 14, 2021, 11:44:51 amBoth 4 wire resistance measurement and high impedance above 10M are about accuracy. They improve the accuracy of the measurement not additional functions.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 14, 2021, 07:11:21 pm
content: With a heavy heart I come before you, to tell you that I have succumbed.My search for a good bench multimeter has lead me astray. I became enchanted by that, which I have sworn to avoid. I have just bought myself a slow booting bench multimeter. A keysight 34465A.The specs were just too much for me. That machine will finally allow me to more or less properly work on battery operated devices. I have decided to re-evaluate my priorities. Physical size and current sensitivity are finally more important to me than boot time. I'll get over those 25-30 seconds. And the price. With the free memory expansion on top of it, I will have gifted myself with a machine that will last me some years. I just hope that the change of OS that some rumour to be coming (the version of Windows CE that is embedded being EOL probably next year) will not suddenly make this machine obsolete. Now on for the hunt for some good kelvin probes.By the way, for future reference, here is my shortlist (and yes, machines of various categories in here, subjectively sorted from good to questionable):(only new, since second hand market in europe is very strained)Clones are not mentioned. And only meters with 4W and built-in ethernet connectivity are mentioned. A meter that has no ETH is outdated.* Yokogawa DM7560: fast boot (don't know how much, but fast), excellent specs and features, but hard to get here, and too deep for my bench.* Tek DMM6500: 15 sec boot, too deep for my bench, otherwise very nice.* Keysight 34461A: 25-30 sec boot, but the 34465A has higher current sensitivity.* Fluke 8846A (aka Tek DMM4050, but no longer sold new): 1 sec boot, but old design, repairs seem difficult* BK 5492C: boot time unknown, 1.2M count, too deep for my bench* Siglent SDM 3065X: 17 sec boot, 2.2M count, too deep for my bench* GW-Instek GDM9061: 1 sec boot, 1.2M count, but noisy (electrically) it seems* Siglent SDM3055X: 17 sec boot, 240k count, otherwise very nice for the price.* HMC 8012: 11 sec boot, 480k count, lower amp range not low enough for me, secondary measurements seem hampered.* AIM-TTI 1908P: 7 sec boot, 120k count, too slow sample rate (1/s), lower amp range not low enough for me* OWON XDM3051: 10 sec boot, 200k count, dual display but no DCV+DCI, looks very price-optimised.I've got more details about most of these meters of course, like ppm, price, sample rate and power consumption. If you want me to add that, can do, but most of these meters are already mentioned in the specialized multimeter topic (and selected numbers never do justice).

author: nctnico
author_rank: Super Contributor
timestamp: May 14, 2021, 10:00:29 pm
content: Quote from: tooki on May 14, 2021, 10:59:57 amSorry, but that is utter nonsense. Since the dawn of the electronics industry you can buy bench DMMs which aren't designed for accuracy. There is more to a bench DMM than accuracy: stackability, better readability of the digits and a mains cord so it doesn't need batteries. I don't get why and how people have gotten the idea that a bench DMM should be all about accuracy.

author: tautech
author_rank: Super Contributor
timestamp: May 14, 2021, 10:10:43 pm
content: Quote from: nctnico on May 14, 2021, 10:00:29 pmYep it's all about needs.Small repair shop 1000km from me uses 3x SDM3045X on their repair benches that give sufficient accuracy, enough capability and zero fan noise.

author: tooki
author_rank: Super Contributor
timestamp: May 14, 2021, 11:19:02 pm
content: Quote from: nctnico on May 14, 2021, 10:00:29 pmSorry, I accidentally said “accuracy” when I meant “precision”.Beyond that, it’s not “utter nonsense”. Look at the bench DMMs on the market: almost nonearen’thigh-precision, high-speed meters. You imply that they’re just the same as handheld meters but mains powered and with different displays, whichisnonsense. Plus, do you see the word “only” in my statement? Nope. Because I wasn’t enumerating what the virtues of a bench meter are. What Iwassaying is thatbecause(practically all) bench metersaredesigned for high precision and high accuracy, they rely on high accuracy circuits that need to warm up.That they have other characteristics is irrelevant to the point I was making.I never said bench meters are “all about accuracy”, that’s what YOU chose to hear based on things Ididn’tsay.So you can get off your high horse now.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 15, 2021, 04:41:46 am
content: gentlemen, gentlemen. It's all a matter of perspective and needs. The claim that "(practically all) bench meters are designed for high precision and high accuracy" is true for some brands. There are however many brands that propose meters with 20.000 count or less. Aliexpress has a nice selection of them. These meters mostly do not need a long warm up. And there is market for them.

author: beanflying
author_rank: Super Contributor
timestamp: May 15, 2021, 05:00:40 am
content: Quote from: bateau020 on May 15, 2021, 04:41:46 amThen off you go as you know the answerFor most of us here under a few hundred K (more like 1 million+) and 4 wire minimum spec isn't a Bench DMM it is a 'Bench formfactor DMM'. Your initial 'requirement' of rapid boot time simply doesn't gel with proper bench DMM's. These are used for more accurate and hence STABLE readings that stability comes after 10-30 minutes so boot time just isn't a factor.Also most non specific 4W capable DMM's as distinct from Milliohm meters SUCK at sub ohm measurements so milliohm resolution is also a bit pointless.Power consumption reallyNothing wrong with screwing a good handheld to the wall and using that if it gets the job done. The pair of junkers below are generally used for USB Temperature logging and sit to one side of my bench. As needed I also use them for other non critical logging jobs from time to time. They are always there but I still use my 6 1/2 digit meters for measurements as they sit on the right side of the bench.So save your $ and buy a good Handheld with connectivity.

author: nctnico
author_rank: Super Contributor
timestamp: May 15, 2021, 07:55:29 am
content: Quote from: tooki on May 14, 2021, 11:19:02 pmAll bench meters? No. Just go around and count the models. You'll see there are way more models with less than 5.5 digits compared to models with 5.5 (or more) digits. Or if you want to go by accuracy / precission (words which mean about the same so let's not start a semantic discussion) better or worst than 0.02% . You just have to look in the right places.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 15, 2021, 08:54:59 am
content: I think I understand the point is this:Quote from: beanflying on May 15, 2021, 05:00:40 amWhat meters are allowed to be called "Bench DMM" and what are not. It is like "Real Men Don't (fill in what you dislike)". Let's just agree definitions/opinions differ. But that is not the point of this thread. This thread did not start out as a "what is a bench meter" question. It started out as "what meters can start quickly". Some can do that, some don't. And yes, although I did not state it, I am aware that for higher accuracy one needs a warm up period. (I don't know if warm-up has an evenly significantly impact on precision though, would be interesting to know.)To steer this discussion to a more objective direction, are there any meters that use low power standby (<2W should be enough if well isolated) to achieve very short warm-up and startup time? Frankly, that would be nice.The 8846A, although a fast booter out of standby, still needs a fairly long warm-up AFAIK. I haven't found them. Maybe they don't exist yet.<rant>And yes,Quote from: beanflying on May 15, 2021, 05:00:40 amLet's not get political here. Power consumption is important to me. Already for the likely related fan noise, as I stated, but also because I try not to be wasteful. Taint me green, yes, I have a solar panel and an electric car. In short, I care. There are more around here that do. My choice. Why would that be bad?And it IS possible. Some meters pull > 30W, some < 11W. Yes, those numbers exist. Even if it pales to the consumption of a hot air gun, it is still something.</rant>

author: beanflying
author_rank: Super Contributor
timestamp: May 15, 2021, 09:08:00 am
content: You clearly are missing any points put so if you ask for information don't argue against it take it in. If you claim to KNOW the answers then don't waste our time!Your opinion and attempted 'required specification' of what makes a Bench meter YOU require is WRONG and shows a lack of basic understanding. Further your requirements read like and are better suited for a good quality handheld and NOT a bench meter.You need to seriously look at and understand what 4W on a bench DMM is and is not. 4W does not make any meter nesecerilly able to resolve 'accurately' milliohms. My three 6 1/2 digit DMMS are put to shame by my milliohm meter by chunks. 4W is not magic.Yep I question 'power consumption' used as you suggest quick boot then measure and then presumably turn off how much power are you planning to save?

author: bateau020
author_rank: Frequent Contributor
timestamp: May 15, 2021, 09:52:54 am
content: Torn between not replying to further feed a discussion that is not really helpful and softening the situation a bit.Quote from: beanflying on May 15, 2021, 09:08:00 amAnd I agree if you take into account only a part of all this, and if you take a specific definition of what a bench dmm is.One of my reasons (that I should have stated more clearly) is that I do not want another handheld; I have enough of them, and some very good ones. I want more desk space. Accuracy is not my prime goal. Hence my quest for a relatively capable and more or less universal tool. Sometimes it will be for 1 single measurement, sometimes it will get prolonged use. Depends on the needs of the moment. Yes, I have a lack of full understanding and no doubt I have false expectations. I do want to learn more about it, it's been a long time since I've used any serious bench meter.And to make this a bit less personal:there are plenty bench meters (or bench formfactor meters) for which accuracy is not the ultimate goal. And still, some of them are slow. Hence the thread.The fact that I chose another meter is for my personal reasons.

author: nctnico
author_rank: Super Contributor
timestamp: May 15, 2021, 11:04:18 am
content: Quote from: beanflying on May 15, 2021, 09:08:00 amI agree here. As an owner of a Keysight 34461A I have to say measuring low resistance is not it's strong suit and it is easely outperformed by other, more specialised instruments.@bateau020: for your requirements it might be better to buy 2 bench DMMs. A cheap everyday one like the VC8145 (I'm using one as a daily driver for nearly 10 years already) and one with more precission / better interfacing for automated tests. Then you have the best of both worlds. In many cases it is nearly impossible to have one instrument fill all the requirements.

author: tooki
author_rank: Super Contributor
timestamp: May 15, 2021, 11:33:14 am
content: Quote from: nctnico on May 15, 2021, 07:55:29 amFirst of all, STOP PRETENDING I USED THE WORD "ALL". That's blatantly dishonest, as I did not say, and am not saying now, that it's "all".Beyond that, let's look at a typical test gear vendor, Tequipment. Of 47 bench meters they have,fourare 4.5 digit, the rest are 5.5 digit and up. Distrelec: six of 88 are under 5.5 digits. Conrad: 13 of 62. Farnell: 21 of 91.Reichelt (which is much more consumer-oriented) is the first one I checked that has more <5.5 digit meters: 14 of 24. But being consumer-oriented, they carry much more low-end stuff, and very little high-end, so in isolation, it's not a representative sample.Sure, if you start including crapola on AliExpress, where low-end stuff dominates and every item is listed 300 times by different vendors under different brands, you'll end up with high numbers, but I don't believe that's even distantly representative of the market, and of market penetration.

author: BeBuLamar
author_rank: Super Contributor
timestamp: May 15, 2021, 12:20:29 pm
content: How can a bench DMM gives more desk space than a hand held DMM? The OP kept saying he needs more desk space.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 15, 2021, 12:29:11 pm
content: Quote from: nctnico on May 15, 2021, 11:04:18 amYes, you're probably right. That or ET3240 or something other cheap. If not only for the startup time of the 34465A probably.Quote from: BeBuLamar on May 15, 2021, 12:20:29 pmGot shelves above the desk. Putting the meter there frees up space. A handheld there is not practical since you risk pulling it off the shelf, you cannot see the screen well, and manipulation is cludgy. Unless I screw it to a wall of course.

author: nctnico
author_rank: Super Contributor
timestamp: May 15, 2021, 12:32:48 pm
content: Quote from: BeBuLamar on May 15, 2021, 12:20:29 pmSimple. You either have to put a handheld DMM in front of other equipment or lay it flat. Neither is ideal. A bench DMM OTOH can be stacked into a pile of other test equipment with the leads tucked away nicely if you want. The result is a much less cluttered work area. I have gotten rid of all my handheld DMMs except one (which I only use when I need to measure something which is not on my workbench) for this reason.

author: bdunham7
author_rank: Super Contributor
timestamp: May 15, 2021, 01:59:50 pm
content: Quote from: bateau020 on May 15, 2021, 08:54:59 amNo, the 8846A does not need any warmup time out of standby--the whole reason it has the standby mode is to keep the LM399 reference heated and stabilized. And since it is a fanless low-tempco design, it only requires about 15 seconds from a cold boot to be fully ready for use. I don't know what its standby power consumption is--probably more than 2W--but it doesn't seem to get warm at all in standby, so likely not much.

author: bateau020
author_rank: Frequent Contributor
timestamp: May 15, 2021, 02:20:35 pm
content: ah, the user's manual says "Accuracy specifications are valid for 61⁄2 digit resolution mode after at least a 1-hour warm-up with Auto Zero enabled."Might be just to cover their behinds.That meter is interesting indeed.

author: bdunham7
author_rank: Super Contributor
timestamp: May 15, 2021, 02:32:13 pm
content: Quote from: beanflying on May 15, 2021, 09:08:00 am4W actually is magic, IMO. But the issue with very low resistances isn't because the 6.5 digit DMM can't resolve milliohms--they certainly can on a relative basis. The problem is the zero point, and that is just a result of measuring the very low voltages involved. So trying to read 1 milliohm with a 10mA test current--the most I've seen from a precision DMM--is the same as trying to measure 10uV and you have all of the same issues. I can get stable readings down below 1mR, but it takes some careful set up of leads and quite a bit of patience. A milliohm meter is one way to make this easier, but I just use a bench PSU and move my 4W source leads to the PSU and supply 1 amp--then set the DMM to volts and I have a microohm meter.If you really want to see magic, look at the Fluke TL2X4W split-jack test lead sets.

author: bdunham7
author_rank: Super Contributor
timestamp: May 15, 2021, 07:03:40 pm
content: So for all you lurkers, here's a deal.https://www.ebay.com/itm/154445651615?ul_noapp=trueThis is a Fluke 8808A equivalent, so make sure you know what that is before you bid. 5.5 digit 100ppm basic DC accuracy, limited high-impedance range, goes for $800-900 new. Dual-display with dedicated segments instead of the matrix-type on the 8845A/8846A.

author: Markus2801A
author_rank: Regular Contributor
timestamp: March 02, 2022, 04:27:47 pm
content: Quote from: PeterKlop on May 10, 2021, 06:46:16 pmHello Peter,did you have time to get more in touch with your unit? I really would like to hear your experience with the GW Instek GDM-9061.