Agilent U1213A Clamp Meter Teardown

[BravoV]

Agilent U1213A Clamp Meter, Teardown & Short Video Review

Recently bought this current top tier Agilent clamp meter for field works. and it will be used to measure big current stuffs in hundreds of Amps both DC and AC in big factory and also for big machines like tractors and etc in mining industrial complex.

Measurement capabilities :

Function	Ranges	Accuracy	Resolution
DC Amp	40A -> 1000 A	±1.5%	0.01A - 1A
AC Amp	40A -> 1000 A	±2% (True RMS)	0.01A - 1A	(45 Hz - 1kHz)
DC Volt	4 V -> 1000 V	±0.2%	0.001V - 1V
AC Volt	4 V -> 1000 V	±1% (True RMS)	0.001V - 1V	(45Hz - 400Hz)
Resistance	400 Ohm -> 40 MOhm	±0.3%	0.1Ohm - 0.01MOhm
Capacitance	4 uF -> 4000 uF	3%	0.001uF - 1uF
Frequency	99.99 Hz -> 999.9 kHz	±0.2%	0.01Hz - 0.1kHz
Duty Cycle	0.1% -> 99.9%	0.3% per kHz + 0.3%		(20Hz -> 2 kHz)
Temperature	-200°C -> 1372°C	±1% + 3°C	0.1°C	(Thermal Type K)

For further details, download the datasheet in pdf about 270KB -> http://cp.literature.agilent.com/litweb/pdf/5990-5083EN.pdf

Actually I was planning to do a short video on it's capabilities at various measurements, sorry folks, too bad at last minute I have to travel, and just finished the teardown shots only. Hopefully I can do it once I'm at home this weekend.

So here we go, the teardown details and comments for each picture at below thumbnails.


01. Standard Package.jpg
Came with the holster and standard Agilent multimeter probes, and not in picture are few paper manuals and the calibration certificate signed at Agilent's Malaysia factory.

02. Holster.jpg
Nothing special actually, it has a separated smaller compartment at inner side enough for probes. Took this particular shot at the back side to show the belt hook up, its made from cheap & thin synthetic leather that I think it can be easily torn up especially this meter is made for field work, Its not that difficult to use stronger or even the exact same material for the holster to make that belt hook-up rather than this crap leather thingy. Ideally I preferred a strong steel belt clip. 

03. Front & Rear.jpg
The body material feels solid and strong, the whole meter's body is stiff enough that won't twist by hands, while the jaw when closed is tightly fit and sealed properly at the tip, and the join doesn't wiggle when twisted gently using fingers. Overall for external build is pretty good imo. For current measurement using the clamp, its designed for one hand operation to open/close the jaw, and to turn the switch using thumb finger as other single hand clamp meter.

04. Back & Batt Cover.jpg
Battery cover is secured by one screw, and underneath it has two IR interface that is probably for firmware or diagnostic purposes, and this IR feature is not mentioned in the manual.

05. Bad & Good Back Cover Screws.jpg
The whole back cover body is secured by only 2 screws, the top and the bottom one which is accessible only when the battery cover is opened. Now the bad part, see for yourself the different among those screws, just hate that self tapping screw at the right one.
Agilent should give the "boot" for the case designer and the one who approved it  , adding just "one" additional nut embedded screw like the one for the battery cover won't add up the cost, especially for this >$300 price range clamp meter, this is just plain bad design & decision.

06. BAD Self Tapping Screw Hole.jpg
Honestly, when everytime I saw this, this reminds me of those cheap China made $15 meter that are using the exact self tapping screw to secure the case.

07. Crappy Battery Connector.jpg
Another bad design, this one is nasty cause I know this pretty much when I was a kid when fixing toys, this kind of 9V connector is well known to have connection problems like broken cable solder joints inside the connector head, and its a pita to fix.

08. DC Current Flow Direction.jpg
DC current direction pointer location.

09. Jaws Join.jpg
One small note, the exposed iron core at the left one is coated with thin clear coating, guess its for rust prevention.


..... continue to 2nd post , 10 pics limit per post ....

[BravoV]

10. Rear Opened.jpg
Back cover opened view, wonder why no RF shield ? Definitely going to test it with a cellular phone actively transmitting while doing measurement.

11. Top PCB.jpg
It has two PCBs stacked, and this is the top one, nothing special, just bunch of resistors and caps.

12. Top Board.jpg
Interesting spot is the fixed jaw at the left has two small white labels, I guess those are some calibration data or part numbers

13. Sensor Connections.jpg
Close up at the Hall sensor connection to the fixed jaw using 8 wires.

14. Jaws.jpg
Opened jaw, the moving jaw with the exposed metal at both ends does not have any electrical connection at all to the circuitry.

15. Top PCB Lifted & Unfolded.jpg
Lifted top pcb, the rotary switch has contact points both at top & bottom boards.

16. Top PCB Various Angles.jpg
Two viewing angles from the top board, looks like this is the analog part for the signal from the probes. Since all current measurement through the clamp only, no fuse needed nor spotted.

17. Double VRefs.jpg
For voltage reference, it uses 2 ics which are LM385 1.2 Volt and 2.5 volt.

18. Bottom PCB.jpg
This has to be the digital part, while small portion near the rotary switch probably for power circuit.

19. Bottom PCB CPU.jpg
Looks like the big ic is the mcu and also below this ic is directly attached the lcd and the front panel buttons. The white piece of plastic probably is a high voltage insulation against the probes handling circuit from the top board above it. I stopped dissambling at the bottom board since the other side/below this pcb are just boring lcd panel and those pads for buttons, nothing interesting there.



About the short video review, my plan actually to show the measurement process at each different tasks, this should at least give a clue how it performs especially for field work such as :

- How fast it reads and settles on various measurements from using the clamp to probes at volt/resistance/diode/capacitance ?
- How is the continuity test beeps ? Is it fast and good enough ?
- The LCD backlight, actually this thing is quite dim compared to other agilent meter I have, you shall see it in the video.
- Testing the meter while placing a transmitting cell phone side to it, this will be interesting to watch cause it doesn't have the metal shield like other Agilent meters I know of.
- etc..etc..

and

- Other suggestions from you guys if you think you want to see how its performing at certain test, I will try my best.

[PetrosA]

Thanks for this. I've wondered since I got my U1211A whether I should have forked over the extra $100 for the U1213A. I didn't need temp or DCA at the time and the extra $$$ didn't seem worth it. Here's what I can say about the U1211A that might give you some things to check on yours:

Voltage readings can take FOREVER to settle down on ACV. I haven't really noticed the same thing with current readings and DCV readings are lightning fast so I'm guessing it's something in the RMS processor. I don't use it for resistance measurements anymore (that's for the U1272A now...) but I've never been upset about the continuity speed. One thing about Agilent meters in general is that they have the continuity beep level set pretty low so that a good light bulb won't make it beep (~16-18 Ohms) so for that kind of test you need to look at the screen.

BTW, I have verified that the IR port on my 1211 does work with the PC software There's just no good way to connect the cable to the meter unless you fabricate a replacement battery cover.

[MarkS]

Never in my life have I had a plastic standoff break through normal use. Only by repeated opening of the device did they break. I think they have a pretty good design there. The screw that users are likely to remove, the battery cover screw, has a metal threaded insert. A typical user will never open the case. Sure, that could have added additional protection with a metal insert, but why?

[BravoV]

Thanks for this. I've wondered since I got my U1211A whether I should have forked over the extra $100 for the U1213A. I didn't need temp or DCA at the time and the extra $$$ didn't seem worth it. Here's what I can say about the U1211A that might give you some things to check on yours:

Voltage readings can take FOREVER to settle down on ACV. I haven't really noticed the same thing with current readings and DCV readings are lightning fast so I'm guessing it's something in the RMS processor. I don't use it for resistance measurements anymore (that's for the U1272A now...) but I've never been upset about the continuity speed. One thing about Agilent meters in general is that they have the continuity beep level set pretty low so that a good light bulb won't make it beep (~16-18 Ohms) so for that kind of test you need to look at the screen.

Thanks, I will re-check again on the settling time at the ACV, currently I'm on travel. But from my faint memory, I think mine doesn't have this slow settling time, but again, I will verify it once I'm back at home.

Yeah, I noticed the U1211A and U1212A series are somehow crippled so badly, thats one of the reason I choose U1213A. Btw, just curious, any chance for your U1211A teardown in the future, really eager to see what are the differences between them.

Continuity test is my case is not too demanding, I'm pretty sure the guys that are going to use it at the field won't bother too much about it's sensitivity.

BTW, I have verified that the IR port on my 1211 does work with the PC software There's just no good way to connect the cable to the meter unless you fabricate a replacement battery cover.

What PC software does it work with ?

Yeah, I don't see the point of using the IR port especially this thing will be used intensively at the field work rather than at desktop, let alone going thru the trouble getting IR signal thru the batt cover.

Never in my life have I had a plastic standoff break through normal use. Only by repeated opening of the device did they break. I think they have a pretty good design there. The screw that users are likely to remove, the battery cover screw, has a metal threaded insert. A typical user will never open the case. Sure, that could have added additional protection with a metal insert, but why?

Why ? I know this is subjective, but with $350 price tag, imo they could have done better, like the metal threaded insert, they already made two of them, why leave out the last one with self tapping screw ? From case construction and plastic molding difficulty level, I don't see why this can not be done easily and "cheap" too.

Again, its all about the price, if this within $75 to $150 price range, personally I can't complain much and will be happy to live with it.

[Zermalmer]

Hi,
I know. This Thread is a little bit older.

A customer sent us two of this for calibraton and both show a very same case defect.

I will try to find out if the customer can comment on the handling and when he bought it.