Part – 5
U1272A – Just another one DMM, with Industrial profile? About single phase and three phase motors troubleshooting, the U1272A simply performs with an excellent manner.
The bright LCD back light offers a significant assistance in the dark engine rooms, the laud beeper is another strong point, which was missing from any DMM up to date.
Tasks like: Shortcut detection, measurement of coils - voltage – current – temperature - capacitor testing, everything is possible with the U1272A.
The new interesting add-on called as high voltage Alert, by setting the trigger voltage value, you can be alerted about over-voltage or spikes.
The only missing feature on it, it would be one phase rotation test about finding the correct phase sequence.
And I will speculate that it’s not that hard to be added, it does have on the display the symbols about positive and negative slope and it can use those two.
Note: I am afraid that I will disappoint the fellow electricians who work exclusively with VFD controllers and variable speed motors.
I do not have access in such systems, and I am unable to test the quality of the Low-Pass Filter, or the accuracy of the U1272A about measuring voltage or current on variable speed motors.
Frequency / Duty cycle / ms About Frequency and Duty cycle, everything works nice, and you have full control on measurements about PWM motors or Inverters, or any type of wave forms, up to 100 kHz.
I have to admit that the
ms function is something that I had never seen before.
It measures the active cycle of a wave form in microseconds.
I test a common 220V mains plug and it was 9.50mS at 50Hz.
In theory by having as known the
frequency / voltage / ms I think that I am able to draw this wave form in a paper, and possibly will look identical with the screen of one oscilloscope.
(I call this one as scientific function, good for students and scientists)
AC/DC Mixed mode: Yes impressive, the least that I can say about it.
I would think that this is useful more for electronic engineers, and complex designs.
If I detect mixed DC in one AC mains socket, the first that I would think would be that I am hunted by evil spirits, or that a troublesome DC/AC inverter is very near to me,
AC/DC Mixed mode +
AC/DC True RMS = I like it !
mV DC mode: My favorite one!
By connecting my Hall type AC/DC clamp probe (PAC 12 Chauvin Arnoux) on the U1272A, the DMM becomes a true Swiss army knife.
The fast measuring rate and those 30.000 counts of resolution, expand the total resolution of my clamp probe in to a further level, the added gain helps the most in the low current measurements.
Those AC/DC Current probes usually cost much of cash, but you can test even the charging current of batteries, and it is more than handy to be able to measure AC/DC amperes, especially in our days that in the name of Green-Energy, the Inverters and the batteries had become such close friends.
Part – 6
U1272A – Accuracy? How it feels on common tasks? Easy to use?
Resistance / capacitance / Diodes / DC-volts /
Agilent is a very respectable brand name about accuracy and measurements world wide, and I feel too small about challenging them in this area.
But I am crazy enough so to try it, even if they use the latest Fluke calibrators, or even offer a calibration report with its U1272A right from the factory.
I did my own accuracy tests, even by comparing U1272A side by side with the Fluke 28II (Brother of the 87V), or even by using some basic Precision Reference sources that I own.
Portable voltage and current calibrator:
1030 MicroCal (Time Electronics U.K.)
And my Home made resistors decade box: Resistors DALE USA 0.1% , 10 micro Ohm to 999K ohms.
Silver plated switches by JANCO California (airplane cockpit parts)
Plus one DC Precision Reference LT1021 10V
by Linear Technology Corporation in California.
After the end of my testing cycle, I can only say that I have lost my chance to find something wrong with it, and I ended up with a large smile on my face, even if had lost in this specific challenge.
The U1272A and the Fluke 28II and my testing gear, looks as one properly tuned orchestra.
The U1272A is a bit faster, and in the ohms range it is a pleasure to watch it.
The extra speed has also and one small downside, when you measure mV and the source is not that stable, the digits on the LCD will update in a high rate, which makes it a bit troublesome to watch the readings.
Thankfully Agilent added to it one function called as (Smooth), it can be automatically or manually activated, and adjusted by the user.
By adjusting the samples to about thirty, I did solve the problem in the specific measurement that I had a problem with.
There is many ways to deal with rabidly changing voltages, (Max/Min) it can assist too.
The Fluke 28II haves the same function, but it is a fixed factory preset.
The (Smooth) mode on the U1272A it’s totally customizable.
Basically this is the key point of the U1272A, everything is totally customizable.
With a minimum of effort you can adjust it so to fit in, in your specific need.
Easy to use?In the beginning when I got the unit, and I realized that I had to get in those menus and sub menus, and I started to dislike it.
I am 42 years old, and I do need good quality and easy to use tools.
I do not have any more so many free brain cells, as I was had when I was twenty years old, so to memorize all those extras, that Agilent loaded on the U1272A.
And even my vision, had just start to play games on me, about reading tiny letters in close range.
I changed my mind about it, as soon I discovered how useful the U1272A can become with all the extra tweaking.
By thinking the digital menu, as to was another one round range switch,
I found my balance, and now I can get in the menu and adjust anything in seconds.
Part – 7
U1272A – Robustness Test - Back light durability – battery consumption Robustness Test:I never had an Agilent DMM or another Agilent product in my life, and some how I needed to find out how robust the U1272A truly are.
The good part of participating in such testing events are that you have the Agilent HH organization on your side, and its like having an endless warranty plan, and so my hands was free about stressing it, with no second thoughts.
I loaded on it, my fresh rechargeable Ansmann 1100mAh batteries (930mAh nominal), the most powerful NiMH AAA up to date.
And I set it to run for hours on (Auto) data logging with small intervals like 1–5 seconds, so to be always busy.
I repeated those stress tests lots of times, in some of them it was running continuously for 30 hours.
In total it did about 14 days of data logging.
Back light Durability:The plan was to find out:
1) If the back light circuitry are durable enough?
2) If those LED’s are durable enough?
3) How the DMM behaves with extremely discharged batteries?
My NiMH was at 50% of charge at the beginning of this test, confirmed with the Ansmann digital (Professional battery tester).
Everything was ok at the first 12 hours, and I let it run for even more.
At about 14 hours in total, the batteries had lost all their charge and the back light was still on, but the LCD digits were fading to the point that you could not see them any more.
I turned off the unit, loaded fresh charged batteries, and it booted up ready again for even more action.
Results:LCD Back light circuitry = Immortal
LED durability = Excellent
Extremely discharged batteries = No problem
Battery consumptionBy my measurements:
9-10 mA: at every AC mode = Active RMS converter.
3-5 mA: other modes.
+1 mA: Active data logging.
0.03 mA: sleep mode (Not uA so to keep it simple)
56 mA: AC Mode + Back light High
45mA: the back-light alone (There is four active LED in it).
I could not resist testing the Fluke 28II against the U1272A. About 14 months back I got one Fluke 87V I was happy with it for about six months, even so I did get the Fluke 28II at the end, because this has IP67 and is more suited for what I do.
The first thing that I did notice on the 28II, was the less bright back light in comparison with the 87V, it looks to have only two LED as display back light, but it does have back light for the key pad. (I love the back light on the key pad)
28II : 2.0 mA: at every AC mode
1.8 - 5 mA: other modes.
0.07 mA: sleep mode
13.6 mA: AC Mode + Back light low
33.5 mA: AC Mode + Back light High
31.5 mA: the back-light alone (There is two active LED in it)
Well if I remove the back light consumption from the equation, the Fluke looks to handle better the battery consumption.
From the other hand, the specific Fluke has only two LED on the display = 50% brightness in comparison with the four LED on the U1272A = a very bright display.
Personally I will give my vote to the bright display and I will move on.
One battery set of four alkaline in a year time it is not a big deal.
And there is no need to say, that if you get rechargeable batteries, you will be able to do endless (Auto) Data logging with out thinking about batteries.
About running the DMM with NiMH, and according to my rough calculation, if my AAA NiMH can truly deliver nominal 930mAh I would had 93 hours of continues operation ( Auto data logging)+ (AC mode = 10mA) = 4 Days.
On any other mode with an average consumption 2-4mA, on another rough calculation it will probably run with NiMH for about 310 hours (13 days).
With high quality alkaline the duration in hours will probably increase.
Dave L. Jones is master on such calculations I will accept his word as fact, about the average battery life with alkaline.
Part – 8
U1272A – LCD display – Multiple functionsThe dual display serves best the AC + DC capability, and the Data logging.
The main display has nice shaped digits, they are large enough, and you will not have any trouble even by watching them under angle.
I hate the LCD displays with the fat bold digits, the U1272A has elegant fonts and symbols, but I need to nag a bit for the symbols around the range switch I would prefer them to were a bit larger.
About the second line with the smaller digits, I like to watch the thermometer in the top of the display.
I would probably expand the functionality of it by using my own ingenuity, as personal reminder about getting a hot or cold coffee, according to the weather or season.
Part – 9
U1272A – Front and back panelI would not change anything on it, or almost.
The DMM it’s not bulky or over-weight, the rubberize body of it, it does protect it against impacts and offers the anti slip characteristic.
The probe holders at the back works nice, the probes get in the holder with a gentle move, and they stay securely in place.
The addition of the hang hole it does help allot too.
Easy fuse and battery access, yes it is easy, I just hate the tiny screws on the battery cover. (I will not stop nagging about that)
About the IR-USB slot on the DMM I would prefer to have a rubber cover, so to be protected against dirt.
And if this rubber cover was connected with a rubber ring, I could possibly pass it thru from the IR-USB cable (when the slot are in use), and it could stay there secured on the cable, until to finish the job.
The body of the DMM it is very well balanced, by having in mind how stably it stays with the tilt stand open.
I do not know how I will feel if I see any damage on the rubber body of this multimeter, caused by a small accident like a burn or damage from a sharp object.
My suggestion to Agilent would be to make easily available all the external replacement parts of the U1272A, in a friendly pricing, so to stop thinking about it.
About the key pad, I am a bit skeptical or I worry too much about those symbols on it, and the possibility to fade in long term. (I love to press those buttons!!)
Part – 10
U1272A – Testing under extreme temperatures I love my tools and I do babysit them allot, and so I am always careful with them about to not exposing them to extreme temperatures with out a good reason.
But because of this review, I took advantage of the hottest summer days in the hart of July in Greece, so to perform the Extreme temperature test.
The plan was to find out what happens with temperatures above the 40C.
And because I love comparisons, I set the U1272A and the Fluke 28II under the direct sunlight for 45 minutes.
As soon the internal K probe of the Agilent stabilized in the temperature of 45.5C,
I took both units instantly back in my work shop, and I tested their accuracy at 10V DC, and the Ohms range.
Both units were spot on.
Other observations from the extreme heat test:
No problem with the LCD at such high temperatures, like fading digits, or no digits at all.
The orange is a bit darker color than the yellow Fluke holster, and so the U1272A it did run a bit hotter internally by +3C.
The paradox was that at 45.5C = 113.93F the Fluke holster started feel as very sticky in my palm, I got motivated to check and the U1272A, and I found that the rubber body of it was very hot as expected but no sticky.
Part – 11
U1272A – Build to last & Conclusion
Even 30 years back the DMM industry was capable to create well made DMM, and some of them are still alive.
I got my first semi professional DMM before 22 years with my first toolbox and it was made in Taiwan (Pros’-Kit with Mastech PCB), still have it, and the accuracy is still good enough.
Some others were made 25 years back or more, and I got them at 2010 as second hand cheap and still accurate for simple tasks, like those old Fluke bench top 8010A 8012A 8050A.
I am also happy even about finding this old analog BBC Metrawatt MA4S (Industrial version of 1987), silver plated PCB / easy to read / 25A range,
I needed one true needle to be on my work bench for special purposes.
And I have even in good use my tiny UT30D from Uni-Trend Group Limited, as I can easily hide it in my toolbox.
Nice made tools, some of those were made with excellent craftsmanship, but they do not belong in the category of the main tools by having in mind the modern needs of 2011.
Modern CAT directives, New safety rules, Inverters, square waves, variable speed motors, Pulse With Motors, Duty cycle, and many more demanding measurements, leads the modern technician so to upgrade and select new and modern tools, capable to handle the modern needs.
My latest upgrades were the Fluke 28II as True RMS, and the UNI-T UT15C volt-tester with phase rotation test.
Excellent tools made by respectable brands, respectable for different reasons, but still respectable at list by me.
Conclusion:The U1272A is an excellent modern multimeter, my answer to the Agilent HH marketing organization would be that yes, the U1272A it did managed to empresses me, and so I am suggesting the U1272A for advanced troubleshooting on the field and bench work, it is a features rich DMM at 30.000 counts.
The teardown video of the U1272A, presented by Dave L. Jones electronics engineer, and owner of the EEV Blog. (Episode #171)
Revealed high quality in manufacturing and high quality parts from respected parts makers like the DALE resistors, and IC’s.
The latest firmware 2.0 improved the software of this mini computer by allot.
Not to say that the easy firmware update method with the use of the IR-USB cable, raises the expectations about adding on the U1272A even more options in the secondary functions.
My personal wish list would be:
1) Low voltage warning (I need that, I really do)
2) Temperature: High/Low warning
I would predict that soon enough the U1272A it will get one large market segment, every modern professional appreciates and builds confidence, by having next to him one company who responds back and solves any issues in just few weeks.
Those new DMM uses lots of software in them, they are complex to build, and we are aware of it, we are professional’s technicians too.
This is why the active link between us and the manufacturer, it is so important to us.
The U1272A it is a modern tool for experienced technicians and the experienced technicians are few and picky.
We feel good about our investment in tools, when there is proper availability of spare parts, at reasonable prices, and with world wide coverage.
Agilent needs only to improve the spare parts sales on their website.
With one well organized E-shop, I would have fewer second thoughts about to become an Agilent customer too.
I like to thanks the Agilent HH marketing organization, for the opportunity that they offered to me, about reviewing the U1272A.
It was a major technical & educational experience for me.
And I feel wiser all ready. KIRIAKOS TRIANTAFILLOU
GREECE