U1273AX is an commercial trick ??? - Page 1
Forum section: electronics / general

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 12:59:04 am
content: Hi there guys .So im the owner of an U1273A.Mine U1273A has the following temperature rating, from: -20C° to 55C°.The U1273AX is going from -40°C to 55°C .Basically both of this DMM's got the IP54 water and dust resistance.Mine suspect is this :i think that both of them are indentical and maybe are also tricked by the internal software to operate only in the allowed range of temperature.So for example, mine U1273A is limited up to -20C° ,meanwhile the U1273AX model is unlocked up to -40C°.At this point guys ,i hope that somebody can show to us some teardown of the AX version to be sure that both of them are really defferent from inside.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 08:22:21 am
content: Quote from: JoeN on December 28, 2016, 08:12:33 amwhat's wrong man ?the A and AX version have both IP54 grade protection,but for some reason the AX can go deeper in cold temperatures.So i just want to check the internal differences over them.If you have the AX version ,please post an teardown ,because i didn't find something on google images.

author: TheAmmoniacal
author_rank: Unknown
timestamp: December 28, 2016, 08:43:25 am
content: Okay, I will give a serious answer...The temperature range given by Keysight is the temperature range for which the device is guaranteed to work.The only real difference between the two meters is the screen, the AX is OLED, the A is LCD.The LCD itself will not operate properly below -20 C, because the liquid become too viscous and crystals within it won't rearrange properly.The OLED can operate down to -40 C before it freezes up.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 08:57:09 am
content: Quote from: TheAmmoniacal on December 28, 2016, 08:38:30 am

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 08:59:30 am
content: Quote from: TheAmmoniacal on December 28, 2016, 08:43:25 amU1273A KEYSIGHT is still an oled display ...............

author: TheAmmoniacal
author_rank: Unknown
timestamp: December 28, 2016, 09:02:16 am
content: Quote from: Ig_sherwood on December 28, 2016, 08:59:30 amDamn you are right, no idea thenGood questionBut no, there's nothing inside the meter that will make it not work at some temperature.

author: EEVblog
author_rank: Unknown
timestamp: December 28, 2016, 09:02:46 am
content: Quote from: TheAmmoniacal on December 28, 2016, 08:43:25 amI think in my Fluke 28II test video I put it in the freezer and you can see the LCD segment update really slows down at -5degCThe fluid does indeed become viscus.

author: JoeN
author_rank: Frequent Contributor
timestamp: December 28, 2016, 09:03:46 am
content: I'm laughing because I've never seen an instrument or IC that will check the temperature and if it is out of the guaranteed range, it will refuse to work. The guaranteed range may be from binning or may be from some subtle difference of the way that part is made or the parts that the instrument is made of (eg, the manufacturer may simply be using the wider temperature grade parts from their suppliers, and the suppliers may simply be binning parts based on manufacturing testing), but there is never a lockout. What happens is simply that the performance was not tested by the manufacturer out of that range and it is not guaranteed to work or work quite to quoted tolerances. TC is a real thing! But hey, you might get lucky. In fact, you might get lucky nearly all of the time, depending on different factors. But there is no lockout like you were talking about.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 09:27:29 am
content: For those who really doesn't understand me....Im talking about that maybe the difference over the both models are just the Letter X at the end + the final price,so this means that maybe Keysight haven't really made an different multimeter from the U1273A.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 09:29:29 am
content: What is the thing or things which makes the AX model more resitent then the U1273A ?Did you have some pics of the internals ?Can you show me something???Where are the specifications which can tell us about why this model is more realible under -40C° then the simple A model???There are this details about it ?What is making the AX model more resitent,better enclousure,better isolation ,better IC's ,what??Pls show me this information and i will keep my soul in peace.

author: wraper
author_rank: Unknown
timestamp: December 28, 2016, 10:28:43 am
content: Have you heard about different working temperature range grades of the electronic parts? They don't need to have any different construction, just tighter testing and tolerances. So all need to be done by Keysight is either use more expensive grades of the same parts. Or even just do a tighter testing of the assembled boards, while using the same parts.QuoteUnlocked. Nobody have lock it. That means operation to the spec below -20oC is not guaranteed.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 11:21:27 am
content: My question was born just because i was unable to see some teardown of the AX model.

author: VK5RC
author_rank: Unknown
timestamp: December 28, 2016, 11:32:43 am
content: @IgSherwood - sorry I can't help answer your question - at those temperatures the battery could start to degrade in function- perhaps better battery temperature insulation. According to the Product data sheet they weigh the same - so the difference may be pretty small.I am a happy U1253B owner x2 (and no - there hasn't been any OLED problems) I really like the display.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 11:40:52 am
content: Happy new year to allP.S I really love teardowns

author: SeanB
author_rank: Super Contributor
timestamp: December 28, 2016, 12:57:44 pm
content: Just a guess is that the extended temperature range is because of electrolytic capacitors being replaced in the AX version with either solid tantalum, solid electrolytics or extended range versions, along with slight differences in the sealing materials to improve low temperature performance, so replacing cheaper elastomer materials with a wide range silicone. These are all higher cost options, so reflected in the price for basically the same meter.

author: Ig_sherwood
author_rank: Regular Contributor
timestamp: December 28, 2016, 02:10:20 pm
content: Thx ,you was very useful