Recommendation for garage multimeter -- must work in full sun! - Page 1
Forum section: electronics / testgear

author: torch
author_rank: Frequent Contributor
timestamp: July 18, 2025, 08:07:55 pm
content: I have a number of digital handheld multi-meters, from Chinese cheapies to keep in the trunk or under a motorcycle seat to a decent Fluke. They all suffer from a common problem -- the LCD display does not care for full sun. The display tends to disappear and while sometimes it comes back when the unit cools, sometimes the display is permanently damaged.Is there a design out there, suitable for automotive use, with a sun-tolerant display? I don't need fancy features like bluetooth and uA. Something like DC voltage up to at least, say, 30v with one decimal place accuracy. 300vac @60hz would be nice. Ohms and continuity. DC amps (20A would be nice, but most are 10). A backlight for night or under the dash. Some measure of splash resistance in case of rain and tough enough to get tossed in the top of the toolbox.

author: Gyro
author_rank: Super Contributor
timestamp: July 18, 2025, 08:28:16 pm
content: Until you mentioned a backlight, an old Fluke 25 / 27 was a good fit. Built like a tank and Mil spec. Operating temperature spec of -15 to 55'C (85'C storage).EDIT: LCD polarizer UV damage is likely to be a problem with all LCDs over time though, not just temperature.

author: Fungus
author_rank: Super Contributor
timestamp: July 18, 2025, 10:30:46 pm
content: Analog meter?

author: DaneLaw
author_rank: Frequent Contributor
timestamp: July 18, 2025, 11:34:20 pm
content: Many vendors highlight good sun visibility on models with implemented TFT/LCD screens, and they often give you a brightness slider, but the penalty comes in battery-drain.If its for "garage work" bikes, cars etc... A clamp meter can also be handy, and quite a few of these have most of the DMM-feature-palette incl..

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 19, 2025, 12:02:25 am
content: LCD panels don't like heat. It's not the light from the sun, but the warming up that wrecks visibility. It's also common with bicycle "computer" speedometers. I also had one going completely black on me during a a bicycle trip on holiday in France. But the display did recover as soon as it cooled down again.

author: danno_cj
author_rank: Contributor
timestamp: July 19, 2025, 03:02:36 am
content: Oled multimeters could be the answer but are more expensive. The cheapest must come from Uni-T UT171C or Voltcraft VC590, CEM DT-9968/9968BT. Keysight also have models but come with premium price.

author: BillyO
author_rank: Super Contributor
timestamp: July 19, 2025, 03:49:19 am
content: "Garage" implies there is protection from sunlight. It also implies precision is not essential. A good analog meter will sustain reliable operation in direct sunlight and will be plenty good enough for all "outdoor" automotive needs. OLED meters really, really suck in direct sunlight and LCDs get hot and black and both can be easily damaged by prolonged exposure. However, that damage takes a little time so, if life and limb requires you to work in direct sunlight, shade your meter when not in use, and make your measurements expediently. I have both a cheap digital meter and a decent analog meter in my garage. Between the two I get by very well.*** The following is supposed to be a joke, but... ***If you need uV precision out in the desert at noon for extended periods, "ringing" out your '66 Valiant, perhaps a psychiatrist might be of more help.*** Back to facts ***Just a little fact. I have kept a multi-meter in my glove compartment since 1977 when I bought my first brand new car. 8 meters have held that glorious position. In all that time I have used one 4 times. Mind you, one of those times it saved the day, money and effort well spent. But

author: Psi
author_rank: Super Contributor
timestamp: July 19, 2025, 04:29:04 am
content: Quote from: danno_cj on July 19, 2025, 03:02:36 amAlso they CHEW through batteries. But yes they are much easier to read.

author: BillyO
author_rank: Super Contributor
timestamp: July 19, 2025, 04:40:25 am
content: Quote from: Psi on July 19, 2025, 04:29:04 amChew? Maybe, but they suck in full sunlight and UV will kill them quick.

author: Psi
author_rank: Super Contributor
timestamp: July 19, 2025, 04:40:59 am
content: Sorry yes, fixed,It depends why exactly the sun is a problem.Sometimes the issue isn't sun on the display but the fact that you are on your back looking up and sun is shining at you making it hard to see the dim reflected light on an LCD. So moving to a display that emits its own light, like OLED, can help a lot.If you have enough sun/reflection hitting any display its going to be hard to read.

author: torch
author_rank: Frequent Contributor
timestamp: July 19, 2025, 07:14:36 am
content: Quote from: danno_cj on July 19, 2025, 03:02:36 amThat Voltcraft VC590 looks interesting. I wonder if the screen is visible in bright light though?Quote from: Fungus on July 18, 2025, 10:30:46 pmDisplay works, accuracy is adequate for the need, but they tend to be less tolerant of life in a toolbox.Quote from: danno_cj on July 19, 2025, 03:02:36 am"Garage" was meant to imply where it lives. In my case it often gets dragged outside because there's too many other things that also reside in the garage (work benches, machine shop, welding shop, winter tire storage, etc. etc.) Not much room left to actually do any work on a car, never mind a boat on a trailer, etc.Guess I can cross the OLED Voltcraft off the list then.Quote from: danno_cj on July 19, 2025, 03:02:36 amI must have worse luck. Or older vehicles. And friends with older vehicles... <lol>

author: darkspr1te
author_rank: Frequent Contributor
timestamp: July 19, 2025, 07:46:39 am
content: I have had a e-technics dual type multi meter for the last 15 years, i regularly leave it on a dash in the african sun and it still works.this is a similar modelhttps://www.alibaba.com/product-detail/KT7310-Original-Authentic-Precision-Digital-Dual_1600513659523.html?spm=a2700.details.you_may_like.1.d36b6346zIgIakmine is the kt7032 which i cant find on the net but the kt7340 does pop up although it's a different shape but identical in all other ways.https://www.ebay.com/itm/186221284028?chn=ps&norover=1&mkevt=1&mkrid=711-153320-877651-5&mkcid=2&itemid=186221284028&targetid=325425753764&device=c&mktype=pla&googleloc=1028770&poi=&campaignid=20797223261&mkgroupid=156754070580&rlsatarget=pla-325425753764&abcId=&merchantid=745738218&gad_source=1&gad_campaignid=20797223261&gbraid=0AAAAAD_QDh_03El3g8vAOIJOCMqf4C0FQ&gclid=Cj0KCQjwhO3DBhDkARIsANxrhTrspVnUEn64jdW6rNBLebD4NWZrKeI2H-0B_97c6suNZlZN9BJWiPQaAnk5EALw_wcBusual 10amp current rating, cat 3 and battery life you would not believe. i change them once per two-ish years sometime longer.with the dual display i can have my cake and eat it, a great example would be testing dyno's on boats/bikes as the needle show current spike way better than the lcd can update, pulsing from alternators is another thing it shows well.meter will also work without a battery in analogue only for some readings like volts(ac/dc), all in all it's been my goto meter over my Uni-t scope meter or fluke lcd based meters.darkspr1te

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 19, 2025, 11:06:30 am
content: Quote from: BillyO on July 19, 2025, 03:49:19 amNah. Just add a 2 TEU air conditioned metrology calibration lab.

author: tooki
author_rank: Super Contributor
timestamp: July 19, 2025, 11:41:59 am
content: Quote from: torch on July 18, 2025, 08:07:55 pmMeaning what model?I don’t know about cheaper models, but the Fluke 87 V has automatic temperature compensation for the display contrast. I would expect the 28II (aka 87 V Max) to have the same. Those are widely used outdoors, so they’d have to work in the sun.

author: Gyro
author_rank: Super Contributor
timestamp: July 19, 2025, 12:28:41 pm
content: Quote from: Fungus on July 18, 2025, 10:30:46 pmThe red scale markings on analogue meters will bleach out really quickly in full sunlight.

author: Aldo22
author_rank: Super Contributor
timestamp: July 19, 2025, 01:35:54 pm
content: Quote from: Gyro on July 19, 2025, 12:28:41 pmIs that a Ц4324?It will soon be 50 years old.

author: Gyro
author_rank: Super Contributor
timestamp: July 19, 2025, 01:38:11 pm
content: Ha, yes it is, but it faded in the first couple of years, just from sunlight coming through a window (UV block). It's been in a box since then. I've seen plenty of other meters with the same problem.

author: Aldo22
author_rank: Super Contributor
timestamp: July 19, 2025, 02:39:10 pm
content: Quote from: Gyro on July 19, 2025, 01:38:11 pmMine doesn't look very fresh either, but the scale is still good.It is from 1978.You can use it as a cheap LoZ meter.

author: Gyro
author_rank: Super Contributor
timestamp: July 19, 2025, 06:33:57 pm
content: They're beautifully built inside though... once you get past the stamped pitch seal. Still like new after 50 years!.P.S. The only thing that put me off it as a teenager is that the scale markings are (were, back then) not intuitive.

author: torch
author_rank: Frequent Contributor
timestamp: July 20, 2025, 05:04:19 am
content: Quote from: tooki on July 19, 2025, 11:41:59 amFluke 175

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 09:04:37 am
content: On the subject:Apparently it is about 3 different phenomena:1. legibility due to contrast etc.2. heat (IR). The limits of the specification, even 50°C, are quickly exceeded.3. UV light gradually destroys the LCD.If you ask me, I would simply adopt a strategy to keep the DMM out of the sun.my 2¢

author: torch
author_rank: Frequent Contributor
timestamp: July 20, 2025, 09:46:19 am
content: Quote from: Aldo22 on July 20, 2025, 09:04:37 amYeah, that pretty much sums things up so far. I would add that it should be robust enough to withstand minor drops and dings. Not always possible to keep it out of the sun though and every so often I am unable to get it back into a shaded area in time. I lose a meter this way every so often. The most recent incident had me climbing in and out of a boat on a trailer trying to track down a gremlin. By the time I got back to the meter the screen had gone dark and this time the bottom segments never returned.I just thought there might be a better option available than buying replacement meters every couple of years.

author: NE666
author_rank: Frequent Contributor
timestamp: July 20, 2025, 11:52:54 am
content: Rather tangential, and not an inexpensive solution but have you considered something like the Fluke 233, with its detachable screen? All the quality and robustness of a Fluke instrument (with the attendant premium price) but you could position the display independently of the meter body, possibly out of the direct sun whilst you're making measurements.That model has been on the market for long enough that you do sometimes see used units come up for sale in the usual places.

author: coppercone2
author_rank: Super Contributor
timestamp: July 20, 2025, 12:26:03 pm
content: nothing better then a 3478A for maximum visibility

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 12:30:46 pm
content: Quote from: NE666 on July 20, 2025, 11:52:54 amIf this is a solution, there are some options for much less money.For example, the Owon 2100b clampmeter with bluetooth.The measured values are displayed on your smartphone and you can have the values read out acoustically.There are also charts and data logging.https://play.google.com/store/apps/details?id=com.owon.imeterBut the smartphone doesn't like the sun either...

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 20, 2025, 12:56:53 pm
content: A typical non backlit LCD display can be read most clearly under bright sunlight. However, if the OP has problem with the heat from the sun cause the LCD to malfunction (getting too dark) the sun must heat it up very hot. How hot the meter is does the OP know?

author: themadhippy
author_rank: Super Contributor
timestamp: July 20, 2025, 01:31:10 pm
content: instead of trying to read the display why not listen to it

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 02:16:27 pm
content: Quote from: themadhippy on July 20, 2025, 01:31:10 pmThey have closed down.The OWON app that I linked to on the previous page also speaks.

author: torch
author_rank: Frequent Contributor
timestamp: July 20, 2025, 05:15:36 pm
content: Quote from: themadhippy on July 20, 2025, 01:31:10 pmTALKING METERS ARE AN OPTION??? OMG, that would be SOOO handy at times...

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 05:53:44 pm
content: Quote from: torch on July 20, 2025, 05:15:36 pmAs I said, the owon app can do this:https://youtu.be/pLUVRxyz74g?t=1596

author: NE666
author_rank: Frequent Contributor
timestamp: July 20, 2025, 06:09:29 pm
content: Quote from: torch on July 20, 2025, 05:15:36 pmMaybe in some situations. And probably utterly useless and detrimental in others. I don't own one and have never used one so I'm guessing here. My guess/intuition being that it would ineffective at spotting rapid fluctuations or transients. Exactly the kinds of behavior that it might be important to visualize in some cases.I'll add to that: You only need look at the demo given in the YT video linked above to see how slowly (at least, that particular implementation) responds. I'd compare the situation to the continuity beeper, which generally annoys the hell out of people if it is not 'fast'.On that note, I think an audible pass/fail tone would be more useful in a meter. Configure the pass/fail thresholds for the reading, and the meter beeps if the measured value is in range, and goes silent outside.

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 06:31:53 pm
content: Quote from: NE666 on July 20, 2025, 06:09:29 pmYes, this is really only useful for measuring static values if you don't have a hand free to hold the DMM.If you want to record changes, the OWON app can make up to 3 readings per second, which you can track directly or save for later.

author: tooki
author_rank: Super Contributor
timestamp: July 20, 2025, 06:43:11 pm
content: Quote from: torch on July 20, 2025, 05:15:36 pmI think they’ve existed for a long time. But not from any big brands.

author: NE666
author_rank: Frequent Contributor
timestamp: July 20, 2025, 07:18:18 pm
content: Quote from: Aldo22 on July 20, 2025, 06:31:53 pmWhich is exactly why I own exactly that clamp meter:)I was looking for a parasitic drain on my car (which ultimately, didn't exist). A complication being that, as with many modern vehicles, a lot of the controllers remain active for a period after the car has been locked. Using the Owon clamp meter, I was able to log the current drain from within the locked vehicle, watch everything power down and then look for anything remaining or returning over time.It also has pretty good accuracy, for something that is reasonably priced.

author: torch
author_rank: Frequent Contributor
timestamp: July 20, 2025, 08:48:27 pm
content: Quote from: Aldo22 on July 20, 2025, 06:31:53 pmInteresting options. I can see where monitoring parasitic drain could be particularly handy. But I don't actually own a spy phone, I'm an old dinosaur that has stubbornly stuck to my mil-spec, intrinsically safe and virtually indestructible flip phone. Is the BT protocol open? Could one link to, say, an Arduino instead of an app? Would it be compatible with an old I-Phone that doesn't have a SIM card?

author: Aldo22
author_rank: Super Contributor
timestamp: July 20, 2025, 09:02:52 pm
content: Quote from: torch on July 20, 2025, 08:48:27 pmYou can read the measurement data with the ESP32, for example, but the app offers very convenient functions whick you don't have in this way.https://github.com/sercona/Owon-Multimeters

author: torch
author_rank: Frequent Contributor
timestamp: July 21, 2025, 04:00:16 am
content: Quote from: Aldo22 on July 20, 2025, 09:02:52 pmI'll give this a try. I have my late mother's iPhone, which seems to run the app for now. Even if that doesn't work out, it meets the needs as a basic garage multimeter and the clamp function is nice for higher currents. I doubt the display is any more resistant to the sun than any other but the voice function is intriguing and if that works out I can always lay the meter face down (the leads even come out the bottom).

author: Aldo22
author_rank: Super Contributor
timestamp: July 21, 2025, 07:28:28 am
content: Quote from: torch on July 21, 2025, 04:00:16 amThe CM2100B will certainly find its use in a car workshop.Although with 100A it can measure higher currents than a normal DMM, its strength lies in measuring mA (e.g. parasitic drain) without interrupting a circuit.In a car, of course, higher currents than 100A occur.Bluetooth is important, as it is the only way to use the app and thus the logging, charts/graphs and voice output. So don't buy the CM2100 but the CM2100B( e.g.https://www.aliexpress.com/item/1005008209469661.html).As NE666 has already said, the voice output is more of an emergency solution. It always lags a little behind, which can be confusing.This is simply due to the time the voice output takes and the intervals at which it talks.I think it can be really helpful in exceptional cases, but you won't want to use it every day.

author: torch
author_rank: Frequent Contributor
timestamp: July 21, 2025, 11:36:50 am
content: Quote from: Aldo22 on July 21, 2025, 07:28:28 amYes I ordered the BT version. After watching several review videos so I have an idea about the delay issue -- not something I plan to use every day, just another tool in the box. I can see using it when I'm tucked up under the dash wishing I had one or two more hands while the meter lies on the carpet beside me where I can't see it or while I'm jiggling my head trying to get both display and DUT in the same area of the bifocals (Don't get old, it sucks). (Although I suppose it's still better than the alternative!The other potential advantage I can see is the use of the phone as a remote display. That seems to follow the main display pretty closely and could be useful when the point I need to measure is over there but the wires I need to jiggle are over here. In the past I've made up LOOOONG jumpers by putting an alligator clip on each end of a spool of wire (two spools actually -- gotta remember the return path!)The biggest problem will be keeping the phone charged between uses. It's an i-Spy phone so I'm sure it's still trying to do things even when it is "off".

author: BILLPOD
author_rank: Frequent Contributor
timestamp: July 21, 2025, 01:36:21 pm
content: Quote from: torch on July 21, 2025, 11:36:50 am

author: Arts
author_rank: Regular Contributor
timestamp: July 21, 2025, 07:01:55 pm
content: I gave up on LCD display meters years ago. Hard to see, gotta be at the right angle, don't work well at temperature extremes etc.On my benches I'm using mostly Nixie tube meters, except for a Siglent SDM3055 and an ancient HP 3476A, and for portables, LED types.I use Fluke 8040a, Simpson 360-2 (not really "portable", haha) and Simpson 461-2 meters for everything off-the-bench. They are so bright that seeing them at any angle or distance is never an issue. And those NiMH rechargable batteries last forever.

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 21, 2025, 10:23:53 pm
content: I just can't believe the sun can raist the temperature of the LCD high enough to cause problem.

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 21, 2025, 10:29:26 pm
content: Quote from: BeBuLamar on July 21, 2025, 10:23:53 pmHave you never had a sunburn?

author: Fungus
author_rank: Super Contributor
timestamp: July 22, 2025, 02:27:53 am
content: Quote from: BeBuLamar on July 21, 2025, 10:23:53 pmYou ever touch a car dashboard when the car's been in the sun?Quote from: KungFuJosh on July 21, 2025, 10:29:26 pmThat's caused by ionization from UV light, not temperature.

author: torch
author_rank: Frequent Contributor
timestamp: July 22, 2025, 07:42:56 am
content: Quote from: KungFuJosh on July 21, 2025, 10:29:26 pmAs noted, that's UV. The heat is IR wavelength. But you only have to make a slight correction to your comment, like so:"Have you never had a cat?"See? It works now.

author: BeBuLamar
author_rank: Super Contributor
timestamp: July 22, 2025, 06:13:05 pm
content: Quote from: KungFuJosh on July 21, 2025, 10:29:26 pmNo never. I never had sunburn. My skin is very tolerant to sunlight.

author: BillyO
author_rank: Super Contributor
timestamp: July 23, 2025, 02:04:40 am
content: Quote from: BeBuLamar on July 21, 2025, 10:23:53 pmI assure you it can. And quickly too.

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 23, 2025, 03:28:26 am
content: Sure, heat is a problem from thesun, but UV exposure damages LCDs too. 🤷

author: BillyO
author_rank: Super Contributor
timestamp: July 23, 2025, 03:30:17 am
content: Yes, but that takes a little while.

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 23, 2025, 04:31:03 am
content: Heat + UV on a dedicated garage meter. It doesn't sound like it will be used for 5 minutes once in a while. It will obviously also get a sun burn!

author: torch
author_rank: Frequent Contributor
timestamp: July 23, 2025, 08:20:25 am
content: Quote from: BeBuLamar on July 22, 2025, 06:13:05 pmI am jealous.Myskin is highly susceptible to sunburn.

author: Gyro
author_rank: Super Contributor
timestamp: July 23, 2025, 11:41:50 am
content: Quote from: BeBuLamar on July 22, 2025, 06:13:05 pmI don't (want to) know your ethnicity, but you should maybe get checked under one of those UV scanner / camera things that highlights skin damage. You might be surprised.

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2025, 09:43:27 am
content: Quote from: BeBuLamar on July 21, 2025, 10:23:53 pmPerhaps not in all seasons and/or in all locations. But there are plenty of conditions where sunlight can easily heat things up. Have you never experienced hot concrete (never mind hot asphalt!) in the summer? It’s way hotter than the surrounding air, and the sun is why.

author: torch
author_rank: Frequent Contributor
timestamp: July 25, 2025, 12:04:18 pm
content: For those interested, the most recent event (that permanently affected the LCD) was at an ambient temperature of about 30°C (~90°F) in full sun with the sun approximately 60° above the horizon. I didn't time it but would estimate the meter was in the sun for <30 minutes. The meter was sitting on the angled motor well of a painted aluminium boat. I'm guessing the angle of the well is perhaps 20° plus the boat was on a trailer facing north with the stern low so the LCD may well have been pointed almost directly at the sun.

author: tooki
author_rank: Super Contributor
timestamp: July 25, 2025, 05:03:31 pm
content: It also depends on location on the globe and time of day. “Full sun” near the equator is way stronger than “full sun” at a distant latitude, and midday sun is far stronger than early or late sun.

author: KungFuJosh
author_rank: Super Contributor
timestamp: July 25, 2025, 05:22:53 pm
content: Why do I get the feeling this conversation is going to shift into discussing the airspeed of an unladen Swallow?