[Poll] Benchtop DMM Acceptable Power On Time? - Page 1
Forum section: electronics / testgear

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 11:15:48 am
content: I just upgraded to the Keysight 34465A and noticed that it took an age to turn on.I had been using an Agilent 34401A which powers on from fully off (mains disconnect power button) to being able to measure a DC voltage in under 3 seconds. This is about the time it takes me to adjust my chair.The Keysight 34465A takes a whopping 25 seconds FROM STANDBY! The unit isn't even fully powered off. This just leaves me twiddling my thumbs waiting for the unit to turn on when all I might need to do is check a resistor.With the 34401A I could walk to my bench, perform the measurement and be back to my desk halfway through typing an email before the 34465A has even turned on.I know that for any meaningful measurement you should allow your test equipment time to stabilise its internal temperature; but there are times you just need a quick and dirty measurement, so for those general purpose times what is your opinion?

author: Black Phoenix
author_rank: Super Contributor
timestamp: November 18, 2022, 11:26:55 am
content: My first DMM was the 289 and at the time the around 5s from pressing the button until being ready to measure was acceptable for my needs, compared with that the equipment in question can do.At the time I didn't know better, back in 2007. Nowardays after some more years and now also owning the 87V I must say I love the almost instant on of it, to the point that I think the 189 would had been a better choice back at the day.Still I think that anything close to 5sec is the right amount.

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 11:32:12 am
content: I hadn't considered handheld multimeters. A fast on time is even more important with them, since you're always switching them off to conserve the battery.The 189 is definitely faster than the 87IV (I don't have either of mine to hand to check)

author: David Hess
author_rank: Super Contributor
timestamp: November 18, 2022, 12:07:24 pm
content: A handheld meter should be ready immediately. A bench multimeter can take time because it is going to be left on all day anyway.

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 12:08:19 pm
content: I just decided to measure the power on time for all the multimeters my firm has laying around.Unfortunately these are all older models (read software light) so I don't have any comparison to other current model top brand meters.

author: BeBuLamar
author_rank: Super Contributor
timestamp: November 18, 2022, 12:21:14 pm
content: I said less than 1 second for a hand held DMM. For the bench it really doesn't matter.When Fluke said they couldn't repair my 87 (original 87) any more around 2004 they offered me $100 discount if I buy another meter so I bought the 189. A couple of months later they offered me a $100 Home Depot gift card for 1 hr interview about their new DMM.So they came with the 287/289 simulator on their laptop. They asked me a lot about the features but one thing I didn't realize that the simulator hided 2 aspects of the 287/289 that I hated the most when I actually had them around 2015. First is the very slow start up time and second is the very low contrast of the display.

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 12:35:41 pm
content: I agree that a lot of engineers do leave their bench-top equipment on permanently throughout the day - often for good reasonWhich I also will do when I'm making certain measurements.My needs of a benchtop DMM are somewhat sporadic - I might run it 24/7 for weeks, and other times I might use the meter for one or two measurement in the day.So I tend to switch it off when it's not in use.That's before you even get any office managers wanting the equipment switched off to save money on electricity/reduce noise

author: Hydron
author_rank: Super Contributor
timestamp: November 18, 2022, 01:07:24 pm
content: No "It depends" choiceIn my case the ~15s power-up time of my DMM6500 became much more acceptable once I placed a 34401A next to it, so I have something with really fast boot (a bit over 2 seconds, add another second if using the hidden settings-recall option) for quick measurements. The boot time of the 3446xA meters was a major turn-off when I was DMM shopping, and one of the reasons I went for the significantly-faster Keithley.

author: tautech
author_rank: Super Contributor
timestamp: November 18, 2022, 06:42:19 pm
content: Sorry but useless poll, define DMM, bench or handheld. Then edit the topic title to accurately represent what you want the thread and poll to portray.TIA.

author: Grandchuck
author_rank: Super Contributor
timestamp: November 18, 2022, 07:35:03 pm
content: It states at the very top:What is an acceptable boot up time for a general purpose bench multimeter

author: BillyO
author_rank: Super Contributor
timestamp: November 18, 2022, 08:36:35 pm
content: I go into my lab in the morning, turn everything I may need during the day on (if it's not already on), then go get a coffee. Nothing is ever still starting up by the time I get back, so for my process it's meaningless.

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 08:42:33 pm
content: Quote from: Hydron on November 18, 2022, 01:07:24 pmI've added an it depends choice. I didn't think of that option.Had I known the 3446xA meters boot time I may have changed my choice; I still have the 34401A so I guess that will remain as the quick to use meter.

author: Leeima
author_rank: Contributor
timestamp: November 18, 2022, 09:23:55 pm
content: Quote from: tautech on November 18, 2022, 06:42:19 pmI've updated the topic to refer specifically to Benchtop instruments (this was on the poll question but I missed it on the topic).But even that is broad, as I know many hobbyists use handhelds on their workbench as their primary meter - which you could class as a benchtop meter in a sense.The purpose for the poll was to get people discussing the power on time of instruments - I just happened to have an issue with a DMM today.The power on time is not something I have often see on spec sheets or talked about.Ideally I'd want to see the reasoning behind the various choices people are making, but I not familiar enough with the poll tool - if it's even possible.I suspect their would be regional opinions.

author: thm_w
author_rank: Super Contributor
timestamp: November 18, 2022, 10:23:59 pm
content: Doesn't really matter, if the extra time comes with suitable featureset.eg if all it does is display voltage, resistance, etc. and nothing else, it should boot in 2s. If its a sophisticated meter that logs, graphs, converts, has color screen, then 30s is fine.Quote from: David Hess on November 18, 2022, 12:07:24 pmYeah if you are checking a resistor, use a handheld DMM for that.

author: coromonadalix
author_rank: Super Contributor
timestamp: November 18, 2022, 10:29:11 pm
content: 34410a is around 6-7 secs .. witch is acceptable for me

author: sokoloff
author_rank: Super Contributor
timestamp: November 19, 2022, 01:44:23 am
content: If I want a fast, ~2 digits of accuracy measurement, I've got plenty of handheld DMMs that are capable to do that with a boot-up time that is practically zero.If I'm using a benchtop meter, it's almost always for a measurement where the handheld DMM wasn't appropriate for some reason. For those cases, I'm never doing it at virtual gunpoint and the meter has been on all day.

author: bdunham7
author_rank: Super Contributor
timestamp: November 19, 2022, 03:10:51 am
content: A precision 6.5 digit meter like the 34465A is not a 'general purpose' DMM and bootup time is my least concern for an instrument like that. A handheld DMM isn't necessarily what you want either, as those are aimed at portability more than anything else. So a second bench meter that turns on instantly is good to have since it is always in one place and always ready to go (unless the power goes out...). Lots of older bench DMMs fit the bill and are ready to go in a second or two, but perhaps without their ultimate accuracy in some cases. The tradeoff is that they don't do as many things as more modern versions.

author: floobydust
author_rank: Super Contributor
timestamp: November 19, 2022, 03:30:37 am
content: I believe 34401A is roughly 256KB of firmware with no OS. Keysight 34465A was over 30MB last time I checked. That's around 100X more and it takes a long time to boot.Then add the several minutes for the voltage reference to heat up and stabilize. Then add the time to poke around the settings menus. Not much fun.

author: Leeima
author_rank: Contributor
timestamp: November 19, 2022, 09:10:08 am
content: Quote from: bdunham7 on November 19, 2022, 03:10:51 amWhat level of precision do you consider to no longer be a general purpose meter? For me I'm thinking 7.5 digit and 8.5 digit are not general purpose.At my place everyone has at least one 6.5 digit meter.There's not much in the price between a 5.5 digit and 6.5 Benchtop meter, so I don't tend to bother even looking at the 5.5 digit models.

author: skander36
author_rank: Frequent Contributor
timestamp: November 19, 2022, 01:21:27 pm
content: As many said here, I always keep on the table a handheld DMM with enough precision(0.025) for quick measurements. If I need precision of a benchtop DMM (0.0025) then I need it to be stable enough, so it need at least 20-30 min. Even the DMM will be able to load his software and UI ready for measurements, the thermal stability need to be reached, and this is another story...

author: coromonadalix
author_rank: Super Contributor
timestamp: November 19, 2022, 01:48:35 pm
content: Some Keysight have an windows ce embedded if i recall, that's why it can take a while,other Keysight are linux / vxwork ... based ...

author: Black Phoenix
author_rank: Super Contributor
timestamp: November 19, 2022, 01:49:22 pm
content: Quote from: Leeima on November 18, 2022, 11:32:12 amSorry the title before didn't specify type and I'm not that verse with model no.

author: bdunham7
author_rank: Super Contributor
timestamp: November 19, 2022, 05:03:33 pm
content: Quote from: Leeima on November 19, 2022, 09:10:08 amThat's a fair question and I suppose different people use the term 'general purpose' differently. I was thinking 'basic', like check this battery or do a quick continuity check. I'm not at a bench full time or even every day, so leaving the meters on all the time is not really a good option. In the sense that they do everything--capacitance, diodes, current, frequency, digitizing--I suppose modern 6.5 digit meters are 'general purpose', but so are many 7.5 and 8.5 digit models. My thought is that if you actually need 6.5 digits worth of precision, waiting 30 seconds is no big deal--you can turn the meter on first and then get set up to measure.That said, I suppose 25 seconds from standby is a bit hard to understand--why even have the standby function? Still, I think the best solution is multiple meters since it is pretty common to need to measure 2-3 things at once. After some experimentation, I settled on the solution pictured--the 'boot times' from top to bottom are ~15 seconds (2 sec from standby), 3 seconds and 0 seconds. This works better than handhelds because I don't have to rummage around for the meter, find a place to put it and untangle the test leads--it's just there and ready to go. I don't know what you can buy commercially today to replace these.

author: nukie
author_rank: Frequent Contributor
timestamp: November 28, 2022, 05:22:03 am
content: This is a good reason for buying a DMM with a instant on nature. If you are not willing to leave your 6.5 digit meter on 24x7 then buy a fast starting 4.5 DMM. Generally bench meters are meant to be powered on and kept warm. Solar panels perhaps. I can't tolerate a 'booting up' portable dmm.

author: Kleinstein
author_rank: Super Contributor
timestamp: November 28, 2022, 12:24:14 pm
content: The startup has 2 parts: one is booting the OS, that modern DMMs, especially those with graphics or LAN interface use. The parts is doing some self test on power one - for certain instruments new regulation require a self test. The problem there is that a really stringent self test also needs the analog hardware to be reasonable settled a possibly even thermally reasonable stable (e.g. for a heated reference) before the more sensitive parts of the self test are done.With a standby mode the boot time should be relatively short - no real excuse for more than some 10 s there.For high accuracy measurments one needs the warm-up time anyway, but quite often one also uses the meter (maybe not so much a 8 digit one) for tasks that don't need the full performance and just want a fast result. With 4 wire ohms a handheld meter is not really an option there.

author: Jester
author_rank: Frequent Contributor
timestamp: November 28, 2022, 05:15:16 pm
content: What I wonder is, what the hell is the software doing that takes 30s?Many many years ago I got out voted on the OS for a new portable product, the consensus was to use Windows CE I think it was called. Product turned out to be the biggest looser of anything our company ever designed. Boot time was in the order of 5 minutes. We had 90% return rate.Next time round we used Linux, far more complicated product, boot time was 18s

author: Kleinstein
author_rank: Super Contributor
timestamp: November 28, 2022, 06:43:09 pm
content: One part the OS is usually doing is some kind of hardware test and looking for possible present hardware (especially if you don't turn that part off explicitely). Parts of the OS can be encrypted / compressed in some way and may need to be precessed first. There can be some kind of check-disk running to make sure the file systems are OK. Some installations copy hundreds of files to a RAM disk. Linux does a lot of configurations from scrits that need to run through. The newer version are often made for a more up to date hardware, like GHz and more CPU speed - so the developers often don't see the long boot times with a slow system.I don't know about WinCE, but with Linux there is a tendency for many distributions to start and install a lot of features / expensions / compatibility hacks that are often not really needed. For linux this may require to compile your own, hardware specific kernal. Things already get a lot easier by skipping multi CPU support, often not needed with small systems. Reducing this to a bare minimum can speed up the boot time a lot and reduce the required memory.Windows typical would be trying to get a network connection (including waiting for time-outs) in case there is an update available or a time server available.

author: colorado.rob
author_rank: Frequent Contributor
timestamp: November 28, 2022, 07:45:49 pm
content: What's it doing?Booting OS, programming FPGAs, negotiating IP via DHCP, calibration and self test.Depending on what "standby" means, it may need to do everything but boot the OS. The start time could go from 45 seconds to 25 seconds. Programming FPGAs and DHCP are certainly not instantaneous operations.You could get rid of almost all but DHCP by using an embedded system, analog calibration, and ASICs. But that's high-risk and expensive. Time to market for Linux/Android systems with established UI conventions, FPGAs which can be reconfigured, and digital calibration/self-test to ensure long-term accuracy/stability has huge advantages for manufacturers (cost/risk) and for consumers (price/features).

author: sokoloff
author_rank: Super Contributor
timestamp: November 28, 2022, 08:10:40 pm
content: Quote from: Jester on November 28, 2022, 05:15:16 pmDemocracy is a terrible structure for product design and engineering decision-making.

author: Leeima
author_rank: Contributor
timestamp: November 29, 2022, 12:54:53 pm
content: Quote from: Kleinstein on November 28, 2022, 12:24:14 pmI wasn't aware of specific regulations related to self-test, what you've said is all valid.It's now quicker for me to switch on my 500 MHz scope than use the DMM

author: 2N3055
author_rank: Super Contributor
timestamp: November 29, 2022, 01:20:55 pm
content: There are few confusions here..First standby doesn't necessarily mean OS standby. It might mean some parts of device stay powered (OCXO, voltage reference) but system still boots full every time.Also I'w seen WinCe devices that booted in 8-10 sec. With full GUI.There were ways to optimize which parts of CE get loaded, and which you don't need at all.Same thing is happening with Linux today: if you use "lean" distribution tailored for the hardware you can get super fast boot. If not, it boots much more slowly..