Agilent U1253B Multimeter - Page 1
Forum section: electronics / testgear

author: Bryan
author_rank: Frequent Contributor
timestamp: June 15, 2013, 04:49:00 am
content: All:Watched the video review of the U1253A meter and Davey was quite critical of the speed of the continuity tester on the ohms range. Has this been improved in the U1253B model.Cheers and thanks

author: saturation
author_rank: Super Contributor
timestamp: June 15, 2013, 11:57:05 am
content: The wear out of OLED and burn in would be a bigger concern if one kept the meter for a few years:

author: M. András
author_rank: Super Contributor
timestamp: June 15, 2013, 01:10:35 pm
content: hmm the oled technology is not in the teenage years i assume

author: saturation
author_rank: Super Contributor
timestamp: June 15, 2013, 01:13:53 pm
content: From the Agilent forum, that photo was from a DMM barely a year old.Quote from: M. András on June 15, 2013, 01:10:35 pm

author: M. András
author_rank: Super Contributor
timestamp: June 15, 2013, 01:28:06 pm
content: thats not a good sign on the usability side if you wont see anything from the burned in parts of the oled screen

author: Bryan
author_rank: Frequent Contributor
timestamp: June 16, 2013, 11:18:23 am
content: Not a good sign, but perhaps there was a issue with the particular DMM, I am sure if it was significant problem there would be reports all over forums. But back to the original post, how is the response on the "B" version with regards to the continuity test.Cheers

author: nanofrog
author_rank: Super Contributor
timestamp: June 17, 2013, 06:59:44 pm
content: Quote from: Bryan on June 16, 2013, 11:18:23 amFWIW, I have a U1252B, and the continuity is still on the slow side. Usable if you slow down a bit (say ~1 second at a probe location or better), but nothing to rain praise down over, that's for sure.If I'll be doing a fair bit of continuity testing, I switch over to a different meter. Not that big of a deal to me, but I do have more than one meter to use when issues come up.

author: Andrusca
author_rank: Contributor
timestamp: May 22, 2014, 08:51:35 pm
content: Hello,Regarding the OLED wear out, I have a U1253A bought in 2009 that now has a completely fade display. It last less than 5 years. But the best of all is that the Customer Service Representative told me (quote) " I have looked up the model information and it states if the unit is no longer in warranty then it is cheaper to purchase a new unit. We have no repair option on this unit. I see the warranty expired June 16, 2012" So It is supposed that I have to spend USD 500 each 5 years for a new DMM?Beware of Agilent DMM...

author: jpb
author_rank: Super Contributor
timestamp: May 22, 2014, 09:03:01 pm
content: Quote from: Andrusca on May 22, 2014, 08:51:35 pmperhaps you should review this thread, Agilent's response seems to vary depending on whom you approachhttps://www.eevblog.com/forum/testgear/failed-firmware-update-on-u1273a-and-agilent%27s-response/

author: saturation
author_rank: Super Contributor
timestamp: May 22, 2014, 09:17:19 pm
content: It can't hurt to complain and see if they give you a new DMM. Firmware upgrade glitch is one issue as it will only affect a small number of owners who choose to try an upgrade. But a failed OLED screen is a different class of problem: it puts all devices with that OLED module at risk and its likely to happen past its 3 years warranty. Can you post pics of that faded screen?Quote from: jpb on May 22, 2014, 09:03:01 pm

author: VK5RC
author_rank: Unknown
timestamp: May 23, 2014, 12:21:26 am
content: I have a ~3-4yr old U1253b, used about 4-6hrs/wk, continuity still a bit slow compared with fluke but oled is fine, note Yaesu also had a problem with some oled screens I think on ftdx 30000,

author: nanofrog
author_rank: Super Contributor
timestamp: May 23, 2014, 12:37:26 am
content: Quote from: Andrusca on May 22, 2014, 08:51:35 pmI'd only be aware of the OLED models (not just Agilent; short lifespan is one of OLED's major issues yet). The LCD versions seem to be holding up just fine. Haven't seen a firmware update made available either (U125xB series' LCD screen models), so that eliminates any temptation to run one and end up with a bricked unit (happenstance perhaps, but I'll take it). There's also the users' choice to skip an update if it exists.In the specific case of Agilent, their customer service seems rather variable outside of the US (based on the "U1253B firmware update fail" thread).But I'm not sure this issue will be limited to just one company, especially for multinational entities.In your situation, $500 definitely doesn't qualify as disposable IMHO, so I'm withsaturation. May not get satisfaction, but you've nothing to lose but a little bit of your time at this point.

author: Andrusca
author_rank: Contributor
timestamp: May 23, 2014, 12:44:40 am
content: Hello,I have just sent an email to KayLee Ritchie, Customer Service Representative saying:"I did not expected that the DMM could not be repaired, since the only thing that has to be done is to exchange the OLED Module for a new one, as it is a separate module. Apart from the display issue, the DMM is measuring well according to the specifications. It had a light use and was always well treated.So if I understand your answer correctly, should I have to spend USD 500 each 5 years for a new DMM? I think this is not acceptable, considering that the U1253A is Agilent´s top-of-the-line handheld DMM and I would expect it were made with high quality parts to last quite similar to my other Fluke multimeter, that has lifetime warranty and never got an issue in far more than 5 years.I would want you reconsider the possibility of repairing the OLED display alone or at least exchange my DMM for a new one at an important discount price. If that is not possible, I would prefer to purchase a new Fluke DMM."If I don´t receive any reasonable response, I´d consider to send a complaint letter to a higher representative person.By the way, I am posting pics showing the OLED display; one is at full and the other at minimum brightness.I´ll keep you updated about my megotiation.Regards

author: saturation
author_rank: Super Contributor
timestamp: May 23, 2014, 11:33:24 am
content: Thanks @andrusca, and from the look of the knob, you have been using this DMM quite a bit. I have the 1252a LCD version, its the same way, the rubber coating is flaking off. Please keep us updated on this thread.

author: saturation
author_rank: Super Contributor
timestamp: May 23, 2014, 11:43:43 am
content: My LCD versions are doing well and I updated the firmware on the 1272a some years ago due to functional defects during the v1.0 release, there has been another firmware update since, but given the 72a works well as is, I'm not updating unless I find a functional problem. My 1252a has been functionally well since purchase but the rubberized coat on the chassis is falling all off. Not something you'd expect in a $400 DMM, but I bought it as a close out for $140.One thing definitely annoying about Agilent's choice of LCD on any model I have, is the contrast is not very high on reflected light whereas on the Fluke 80 series excel on it.Given some reports of Agilent's response to warranty and support on this forum, I hope they realize competition is very keen in the DMM market and for the cost of these meters, every nation should expect premier service and if not, there are other competitors worth considering. There isn't enough unique functionality in Agilent HH DMMs line to warrant spending much more except on the hope of quality assembly and aftermarket support.Quote from: nanofrog on May 23, 2014, 12:37:26 am

author: linux-works
author_rank: Super Contributor
timestamp: May 23, 2014, 03:05:11 pm
content: man, agilent is really becoming the company to avoid, if you don't have bottomless pockets and infinite wallet.I was tempted to buy this oled meter; but now, I would not touch one with a 10 foot pole.I expect 10's of years from my test gear!!! geeze. might as well just keep buying older used gear instead of paying agilent to produce disposable crap.one of the reasons we would choose an agilent is that we don't want to keep rebuying chinese 'landfill fodder'; but if agilent is offering us the same options, uhm, why even consider agilent anymore?sure, its 'only' a $500 meter and not the big boys that agilent also makes; but this shows a side of the company that I'm sad to see and it makes me think that the real test gear company of yesteryear is really no more and the agilent of today is yet another mass producer of crap with no responsibility for long-term tool investment.maybe agilent should just fold up and die, as a company. they've had a really long run, but it sounds like they are changing for the worse and its often a one-way trip once you start acting this way toward your products and customers ;(

author: Orange
author_rank: Frequent Contributor
timestamp: May 23, 2014, 03:34:26 pm
content: When I first saw this OLED meter from Agilent, I already had second thoughts.OLED technology is pretty unreliable, and I honestly don't understand why a company as Agilent went for an OLED display. Sure it looks stunning, but you expect more as good looks from Agilent.The have another bench DMM with an OLED display, I think its the 34250A, looks pretty nice (when its working)Yaesu has the same problems with their $4000,- tranceiver the FT-5000 with two or three of these displays.....I avoid OLEDS in any durable stuff.

author: Terabyte2007
author_rank: Frequent Contributor
timestamp: May 23, 2014, 03:50:08 pm
content: The Agilent handheld DMM's have a few other quirky annoyances too. But in my opinion, OLED is dead. I don't think it's going to last much longer, but's that's just my opinion!

author: nanofrog
author_rank: Super Contributor
timestamp: May 23, 2014, 07:31:06 pm
content: Quote from: saturation on May 23, 2014, 11:43:43 amThe flaking rubber coating issue hasn't happened with mine thus far, but I do see your point, particularly when purchased at full price.Unfortunately due to the general trend of reduced quality, I've become conditioned to reduce my expectations to some extent.Doesn't mean I won't nitpick though (genuinely in hopes that enough similar comments could help turn things around).But like you, I didn't pay full price for mine either (got a U1252B with a $100 rebate). Not as good a deal, but it was still cheaper than a Fluke 287, which was the other model I was looking at (wasn't all that aware of/confident in Brymen at the time). So I'm a bit more willing to accept it, should it happen.Worst case, Agilent does sell the case parts for reasonable prices, and are actually the cheapest source I've found for fuses should you need them (in your case, I'm not sure the blue case parts are still available).Quote from: saturation on May 23, 2014, 11:43:43 amI've not really noticed this an issue on my bench. Outdoors in direct sunlight, I have (need to view it pretty much dead on). Can you reconfigure your lighting by chance (maybe use hoods or white nylon as a diffuser like you would for photography)?IIRC,mjlortondid something like this on his bench, and stated it helped.Quote from: saturation on May 23, 2014, 11:43:43 amI definitely agree. Without such comments (or willingness to pay attention to them), nothing will ever improve, and likely continue to get worse IMHO.Regarding unique(ish) functionality, FWIW the U127x and U125x models are capable of 4 wire measurements (not sure about any of the others).Quote from: linux-works on May 23, 2014, 03:05:11 pmThus far, it's just a couple of people with issues, so though we need to be vigilant with purchases (as per usual IMHO), I wouldn't go so far as to conclude the company has truly gone down the shitter. Users should be vocal about such things to help prevent this from actually occurring though, so I'm not saying ignore issues and blindly give them a pass.I'd also say we need them to keep other companies competitive (not get complacent and churn out warmed over crap each release cycle), as there's not that many players remaining in the general scheme of things (genuinely make their gear, not rebrand).As per OLED, just skip it. LCD works just fine, and has a good track record.Quote from: Orange on May 23, 2014, 03:34:26 pmPretty simple really, the Marketing folks love flashy stuff, and got their way.Quote from: Terabyte2007 on May 23, 2014, 03:50:08 pmI'd like to see it go away in it's current state on T&M gear, but that's me.As per OLED being dead, I'm not so sure. For big screens, it certainly looks that way, but for small screens (i.e. cell phones), it has a larger market that can pay for the R&D (seem to recall that some large OLED plants are being closed, while small screen plants will be expanded). Users are also less likely to notice it's current flaws due to how frequently they upgrade their phones (every couple of years or so?).

author: Wytnucls
author_rank: Super Contributor
timestamp: May 23, 2014, 08:13:59 pm
content: Quote from: nanofrog on May 23, 2014, 07:31:06 pmCould you please explain what you mean by 4 wire measurements, because AFAIK those meters don't do 4 wire resistance Kelvin measurements.The only meter I'm aware of with that feature is the Gossen 30M, which also does 4 wire temperature measurements.

author: nanofrog
author_rank: Super Contributor
timestamp: May 23, 2014, 08:47:54 pm
content: Quote from: Wytnucls on May 23, 2014, 08:13:59 pmAccording to a data sheet I've seen, it does do Kelvin.From Agilent (DMM Datasheet):QuoteSource(.pdf, pg. 17 & look to the upper right).It's also listed in theProduct Compare page.What is strange, is that it's not mentioned in the manuals I've downloaded from what I can see (certainly not indicated under Resistance Measurements).

author: Wytnucls
author_rank: Super Contributor
timestamp: May 23, 2014, 09:11:43 pm
content: Someone got carried away with the specs for the 1250 series. The manuals are probably more reliable. There is no range selector position for a 4W feature and the jacks are not marked for sense anyway. The 1272A has a smart Ohm feature, but that's not 4 wire measurement.

author: nanofrog
author_rank: Super Contributor
timestamp: May 23, 2014, 09:33:29 pm
content: Quote from: Wytnucls on May 23, 2014, 09:11:43 pmI could see that on the compare page, but would think a bit more oversight with the datasheets.In the case of my U1252B, I don't recall anything in it's settings, and oddly enough, still haven't ever tried it (just don't usually think of an HH DMM for 4 wire measurements). Only caught my notice a couple of months ago, when checking/verifying something for a post.Might give it a proper try once I get my mess sorted out (meter's easily available, parts are not as the bench is ripped apart and everything scattered in misc. boxes).Went to try a quick test of what would happen just plugging hot leads into both the V and either current locations (thinking about the probe sense feature), but the battery is flat.Will get it on a charge, as I'd at least like to give that a go and see if the audible alarm sounds or not when set to resistance mode.

author: electr_peter
author_rank: Unknown
timestamp: May 23, 2014, 09:33:50 pm
content: Quote from: nanofrog on May 23, 2014, 08:47:54 pmAccording to that comparison, even 123x series has 4-wire measurent - clearly that is a mistake on the page. I'm not sure about 125x series, but 127x series do not have 4 wire measurement. 127x has typical input layout which does not allow 4 wire measurement.

author: Andrusca
author_rank: Contributor
timestamp: June 03, 2014, 02:42:07 pm
content: I have good news!!Finally afer sending several emails to the Sales Rep. asking for buying them the OLED module ALONE as a spare part, he kindly phoned me and explaind me that Agilent's policy is not to sell electronic modules of its instruments as spare parts and that my case was a very rare one. As a compensation he offered me a NEW U1252A (the one with standard LCD display) FREE of any charge. Of course I accepted it (I don't have a precision DMM working properly at this moment!) and he will send it to Argentina via a Courier service from USA in these days. Well, we both agree that when we are talking about Agilent of Fluke you expect a customer service far better than what you get buying cheap chinese stuff. So now, I think I have recovered my faith in Agilent and this shows that when you are asking for some common sense, it finally shows up...You will hear about me when I receive del DMM!Thanks to all of you for your comments and supportAndrés

author: saturation
author_rank: Super Contributor
timestamp: June 03, 2014, 03:40:10 pm
content: Great, I wonder if posting on forums helped? Keep us updated. They did not offer an OLED as replacement or did you not want another oneQuote from: Andrusca on June 03, 2014, 02:42:07 pm

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: June 03, 2014, 10:03:08 pm
content: I'm definitely glad to hear Agilent's trying to fix up their customer service situation after the whole failed firmware update debacle. I certainly understand that for the typical pro customer, human resources are more expensive and thus claiming "replace instead of repair" is a reasonable MO, but then it also seems like it's worth the few extra bucks to keep faith in the brand when things like this happen. I certainly don't want to be in 30 grand for a DSO7K series and have them dicking me around on repair costs and times, even if I'm more confident it'll get worked out in the end.As for the display, I do LOVE the OLED indoors, and haven't experienced the fade (though I definitely don't use mine as much as you). The battery life is a huge loser, but if I'm inside I'm near the charger and other meters anyway, and if I'm outside, I'm not using the Agilent because the display is totally useless. Luckily, I don't ever need to measure things with 4.5 digit precision outside.Of course, the ORIGINAL question was re: continuity, so I'll speak to that. People seem to complain that the Agilent's continuity detection is slow. That's fair, it is. But it's always compared to the 87-V, which has a much worse continuity mode. Here's why.The way both continuity modes work is to measure resistance and sound a buzzer if it's below 10 ohms or something like that. The fluke is fast because it's sort of crippled, in a way: in continuity, it ranges to the lowest ohms range (600) AND STAYS THERE. So if you probe, say, a 1K connection, you won't hear a buzzer and the screen will display OL.On the other hand, the Agilent uses its full ohms range, so if you probe a short, it'll autorange all the way from the top, which takes some time. It works out that it introduces a delay of a half second or so, where the fluke is more or less instant.Here's the thing though: on the Agilent, you can simply manually range down to the lowest 50ohms, if you really need the buzzer to be snappy. On the Fluke, you can manually range UP to show actual measured resistance, but you can't set it to autorange in continuity mode.I find it's more often the case that, on my bench, I have plenty of time for probing and the quickness isn't an issue, whereas I'd like to see what a value is if it ISN'T a short. For example, probing a power regulator, I can tell "these two nodes are connected" or "here's the top feedback resistor [as opposed to bottom]" in one probe, where with the fluke that'd be a PITA.Basically, the agilent gives you the option, even if the default choice is the slower one. The fluke doesn't, so using continuity secondarily as a resistance measurement is annoying or impossible.

author: saturation
author_rank: Super Contributor
timestamp: June 04, 2014, 11:24:23 am
content: FYI the 1252athat you mention is a discontinued model, its the one I have, but the only difference is the color of the chassis.The current production LCD model is 1252b, cheaper by $50 vs the OLED 1253b.The 1252a LCD was liquidated at $120 before the model was discontinued, just to give you an idea of what the profit margin is on these DMM and likely why repair is worse than getting a replacement [ human labor to repair vs robot costs in production]. I'd consider either LCD model a better deal so as not to have OLED which is a problem waiting to happen, and come out with a working meter of identical functionality.

author: saturation
author_rank: Super Contributor
timestamp: June 04, 2014, 11:35:30 am
content: Technically continuity means near 0 ohms, so the Fluke IMHO is configured correctly: one isn't concerned with the actual ohmic value so it should range low and stay there when selected: even 10 ohms is a bit high for continuity particularly in power circuits. Its a fast troubleshooting tool because the next step if needed is to check the ohmic value.In the 1252a, continuity as you describe is somewhat moot given the time response of both meters, the problem is more the volume and that its non-latched so its harder to hear. Continuity beepers are for field work fast troubleshooting, where its often noisy, so louder is best. Luckily, the 1252a was designed as in electronics meter and meant indoor use or even labs.Quote from: alexwhittemore on June 03, 2014, 10:03:08 pm

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: June 04, 2014, 04:36:08 pm
content: If you're probing for continuity, that's true. But in my experience, I'm rarely probing for only continuity with zero interest in actual ohmic value.

author: saturation
author_rank: Super Contributor
timestamp: June 04, 2014, 04:43:01 pm
content: Yes, you're right likely just ohms is more valuable that the continuity beeper. But it can be a timesaver so your eyes needn't be on the screen. The 1272a flash its LCD with a beep, which is even more helpful than just a beep, and it is near Fluke 87v loud too.Quote from: alexwhittemore on June 04, 2014, 04:36:08 pm

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: June 04, 2014, 04:45:46 pm
content: Actually, now that I play, it looks like the agilent actually ranges down to 500 ohms in continuity just like the fluke - maybe that was a firmware update or something. The agilent also has a convenient "tone" mode for continuity where the frequency of the tone is proportional to the actual resistance, so you can audibly tell the difference between a dead short and, say, 100R. I really like that.

author: saturation
author_rank: Super Contributor
timestamp: June 04, 2014, 06:36:49 pm
content: Really? Hmm will look into it, didn't know such existed.Quote from: alexwhittemore on June 04, 2014, 04:45:46 pm

author: alexwhittemore
author_rank: Frequent Contributor
timestamp: June 04, 2014, 06:44:39 pm
content: Yeah, if you go into setup, second page, under Continuity there are three options, single, tone, and off. Single is what you'd typically expect (latching buzzer, on when short), and tone will beep low-frequency if there's a relatively high (couple hundred ohms) resistance, and will increase in frequency to a continuous tone at short. Off is kind of stupid, it lets you set no tone at all, instead it just displays an open/closed switch graphic on the left of the screen. But it's tiny, the bar graph and display are both much more obvious. You could just as easily display the switch graphic in both other modes. And of course, the display doesn't flash or anything in any of those modes like the 1272 does.

author: Andrusca
author_rank: Contributor
timestamp: June 24, 2014, 12:26:01 pm
content: Well, finally I received the U1252A in compensation for my U1253A. They neither offered me a new U1253A nor I want it! Although the U1252A is discontinued, also it is mine U1253A. So, I think it was not so unfair to receive A U1252A instead of a U1252B. Maybe when I have some spare time, I would try to replace the OLED display by a new one and so I would give this instrument a better use. I think that posting here made some difference in the way that Agilent treated this case. I referenced this post when I contacted Agilent´s technical and sales representatives.Thank you for your comments.

author: nanofrog
author_rank: Super Contributor
timestamp: June 24, 2014, 11:56:23 pm
content: Quote from: Andrusca on June 24, 2014, 12:26:01 pmI'm surprised they had any A variants remaining.But I hope it serves you well, and more importantly, allows you to get back to building circuits.

author: saturation
author_rank: Super Contributor
timestamp: June 25, 2014, 03:31:29 pm
content: Enjoy, and give us any feedback of any major differences between the 1252a and the 1253a or 1253b. IIRC the only key difference was the color and the OLED screen.

author: Andrusca
author_rank: Contributor
timestamp: July 05, 2014, 08:11:20 pm
content: Hello,I have discovered an annoying difference between my old U1253a (with the worn out OLED display) and my just-received U1252a (from Agilent as a compensation). According to the datasheets, both DMM can measure up to 4V in "Diode" function. My U1253a behaves correctly but the strange issue is that the U1252a only displays the right voltage value up to 2V. From this value and upwards, it shows Open Circuit even when actually the voltage is below 4V, as I checked measuring the voltage between the proves using another DMM. I attach two pics showing the test of 2 LEDs in series, one using my U1253a and the other using my U1252a. I would want to know if someone has found a similar behavior in U1252a. I want to be sure if this is a general limitation of this model or Agilent has just sent me a faulty DMM...Thnak you

author: Owen
author_rank: Contributor
timestamp: July 05, 2014, 09:36:36 pm
content: Quote from: Andrusca on July 05, 2014, 08:11:20 pmFrom the user's and service guide (Tenth Edition, May 4, 2012) "The meter can display the diode’s forward bias of up to approximately 2.1 V. A typical diode’s forward bias is between the range of 0.3 V to 0.8 V." .... So it looks like this would be normal. They've probably changed the specs on the newer orange ones...

author: zaoka
author_rank: Frequent Contributor
timestamp: July 05, 2014, 11:10:36 pm
content: Andrustca get HIOKI meter... Agilent meters are full of bugs.I have U1272A and its capacitance range is unusable.. you just cant go to the field..., test capacitor and be sure its OK or not..If capacitor has higher ESR or change in dialectric this meter just cant measure it.. it just keep changing measured value like crazy.. Also if you measure on different range sometimes it shows over 60% of difference...Smooting mode does not work...I also had U3401A they had problem with beeper when measuring diodes..Those big companies they dont care about end users who own less expensive meter.. their representatives cant to anything except collecting user information and statistics..HIOKI, FLUKE or Gossen... i will never buy another handheld meter from different company

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: July 06, 2014, 01:41:24 am
content: Quote from: Andrusca on July 05, 2014, 08:11:20 pmHi Andrusca, can you tell us approximately how many display on hours and total lifetime (including shelf time) for that oled meter?. Wow it is very dim..

author: VK5RC
author_rank: Unknown
timestamp: July 06, 2014, 11:40:02 am
content: @Andrusca, are you aware you still have the LCD protecting plastic on your old U1253A? Removing it may allow a few extra photons out! HiHi

author: nowlan
author_rank: Frequent Contributor
timestamp: July 06, 2014, 12:49:22 pm
content: That is a truly shameful oled display.I am also concerned about the rubber used on edges and dial.

author: Andrusca
author_rank: Contributor
timestamp: July 06, 2014, 11:42:40 pm
content: Hello,@Owen: You are right, but in the DC specifications states it can deliver up to 4.2V (page 152 of the same manual). It is quite pointless to be ready to measure up to 4.2V and only display up to 2.1V. This situation could be confusing in some cases since in my test I have the two leds in series tested that are (poorly) shinning, but the DMM is indicating open circuit. In fact, U1253a manual states (in both user guide and specifications sections) it can display voltage up to 3.1V and it does this ended, as I checked it out using the two leds in series. At the end, I have to accept my U1252a is working according to the manual, but it is a pity I could not detect more than 2.1V of voltage drop when testing for example the behavior of integrated circuits.@chickenHeadKnob: I have the U1253a since September 2009, with 5 hours of use per week aprox. The thing is I sometimes work in dirty environments and my hands are not so clean. Regarding the peeling off, part is due to once trying to clean the knob using Isoprophilic alcohol, I think it softened the plastic.@ VK5RC: Yes, I am aware, but I always prefered to keep it to avoid scratches. I think you are right that is time to take it off... (but I get not much change in brightness)

author: lowimpedance
author_rank: Super Contributor
timestamp: July 07, 2014, 01:31:33 am
content: I just checked 2 RED LEDs each having a Vf of 1.65V on my 1252a and when in series the display is OL, but noted that each LED was dimly lit.So It would appear your 52a is working correctly!. Would be interesting to see if someone with a 1253a or b could also test to see if the display shows the VF or OL.

author: Andrusca
author_rank: Contributor
timestamp: July 07, 2014, 01:51:07 am
content: @lowimpedance: I have made the same test with my u1253a and it shows de VF properly (see my pics in a previous reply). So U1252a is not equivalent (worse) to U1253a in "diode function"

author: VK5RC
author_rank: Unknown
timestamp: July 07, 2014, 08:25:27 am
content: A U1253B doesn't cover 2x1.8V LEdiodes at the same time. It does cover two signal diodes or one LED.From the manual " This multimeter can display diode forward bias of up to approximately 3.1 V. The forward bias of a typical diode is within the range of 0.3 V to 0.8V."The battery (rechargeable LiPo) life is a lot better since the software upgrade, which went well, (battery charging programme terminated early) I reckon I get about 20 hours, mostly 5mins at a time. I last charged in ~April.I have had no problems with the display on my unit now about 3-4 years old, nor the rubber, please see below pics.I have looked on other fora and can not find an 'avalanche' (pun intended) of OLED failures in Agilent DMMs.I have a Fluke 87V as well, but I reach for the Agilent first as the display is so good.

author: saturation
author_rank: Super Contributor
timestamp: July 07, 2014, 02:26:02 pm
content: Yes, not to mislead readers so its good you provide some balance. The key issue is compared to other primary rival display technologies such as standard backlit color LCD or simple reflective LCD, which have ~ far lower rate of failures, relatively speaking.In summary:http://eitidaten.fh-pforzheim.de/daten/mitarbeiter/blankenbach/vorlesungen/displays/ed_OLEDs.pdfQuote from: VK5RC on July 07, 2014, 08:25:27 am