Keysight U1272A / U1273A DMM - Page 1
Forum section: electronics / testgear

author: Vtile
author_rank: Super Contributor
timestamp: November 23, 2018, 10:20:45 pm
content: This meter seems to be pretty mature now, one of the reasons I decided go over it from Fluke 189 / Fluke 87V a few of my colleagues use when pure laptop and ethernet cable doesn't do the trick. I did go through Gossen and Hioki offerings also, but they did seem to be also somewhere in 90s with the Flukes.So it is a personal equipment for troubleshooting industrial machines, mostly control circuitry, some VFDs/Servos) all that low voltage probing, so just the field of use where it is designed for (not pure electronics).So far I'm impressed. I read a lot about that it does have ie. jumpy display, but I must say that I do like that "jumpy" display a lot and haven't found it disturbing, quite opposite. It reveals ie. a bad connection really quickly, since it seems to lock down when constant voltage is applied (it would be defective without).Double display is nice to see not so much the AC+DC so far, but DC + freq. or AC + freq.Also the configurable NC/NO continuity beeper seems to be handy for dry testing control wirings.From advanced features the configurable "alarm voltage level" is a gem. It does flash the back light and beep when the voltage level is above that. So I did put it to 22 volts and now the meter is nice for going through terminal blocks and switch contacts. Bleeb = GO / Silence = NoGO etc.The user configurable scale is rather nice also, but it would be even better with Inversion ability and real preset list with 4 corner points. Even now if you happen to have sensor with say 0 .. 300 bar = 0 .. 10V specs you can just put the scaling factor as 30.0ooo and can read the pressure from the screen. In case of reversed output 0-10V = 100% .. 0% you can but the scaling factor to 0.1ooo and then Null the reading in 10V source and now you do have 100..0% display.There is this negative resistance thing some are freaking out here, but this is something you should expect with null (referenced) measurement, since the point of contact and oxidation of the probe tips varies. Not much use for resistance yet, but one reason for U1272A were the low ohms range down to 1mOhm resolution (not accuracy).There is also jumping numbers (noise) in both dc and ac voltage measurement with open leads and some with shorted ones, but this is something one should expect from high impedance meter picking up random particles and triboelectric charges. I assume Fluke do use much more aggressive LPF or the sensitivity is worse.I wish it would have longer back light time setting (max 99 sec. currently). For situations you are diving somewhere inside the machine with poor light just under that part where the object of interest happens to be.So far happy with this well rounded orange.

author: hgjdwx
author_rank: Regular Contributor
timestamp: November 24, 2018, 01:46:46 am
content: Try using the DCV range of U1272A to test the drain voltage of switching power supply MOS, Than you will find Pleasantly surprised.DT4282 is all right.

author: Vtile
author_rank: Super Contributor
timestamp: November 24, 2018, 09:55:48 pm
content: Which kind of waveform? Do you mean typical PWM as AC with DC offset or some more complex mixed PWM as AC but with several DC offsets?

author: Vtile
author_rank: Super Contributor
timestamp: November 25, 2018, 01:00:08 am
content: What I did say about Flukes others being in 90s I meant that DMMs in my mind are indeed stuck in somewhere in the past. Ie. just look about eevblog member Madires (et. al.) $20 component tester.. That said ie. this Keysight U1272A could be much much more what it is, with just some ingenuity to functional palette. Ie. function that I do not know in any DMM is phase order detection found in 50€ pole testers, but not in 1000€ multimeters, every colleague of mine would pay arms and legs to have it included. Luckily there is again some real competition on the DMM market so Fluke and few other players can not just copy old products with new form factor year after year. Even my now 60 year old AVO8 meter can measure the Amps, Volts and Ohms as name suggest (still in specs btw).I found that in this Keysight they actually did try to include / gather some new / modern features to HH DMM.

author: plurn
author_rank: Regular Contributor
timestamp: January 15, 2019, 12:55:18 pm
content: Quote from: Vtile on November 23, 2018, 10:20:45 pmIf you set "bLit" to "oFF", it disables the auto off timer for the backlight - so the backlight stays on until you turn it off. Might not be exactly what you want but this is the setting I use. Just need to remember to turn the backlight off yourself.

author: rsjsouza
author_rank: Super Contributor
timestamp: January 16, 2019, 07:04:50 pm
content: I really like my U1273A, especially the Smart Ohms and the Zlow. I have used the data logging with the auto trigger (just like Dave on his Resistor tolerance Redux video) and I agree the NC/NO is a great feature.It also has the curious melody continuity tester that I show in the video below.https://youtu.be/fH6rL2U2oAI