Author Topic: EEVblog #56 – Agilent U1253A OLED Multimeter Review  (Read 30268 times)

0 Members and 1 Guest are viewing this topic.

Offline chemicaloliverTopic starter

  • Contributor
  • Posts: 11
    • Chemicaloliver.net
EEVblog #56 – Agilent U1253A OLED Multimeter Review
« on: January 24, 2010, 11:35:17 am »
I've been waiting for this review as when you mentioned you were about to review an Agilent meter I was just about to buy one, initially I planned to wait till after you reviewed it but got fed of of waiting and picked up the model at the other end of the range, the UT1241A and I'd just like to add a few comments.

The U1241A seems to not have some of the issues that the U1253A has, firstly it uses 4 AAA alkaline batteries which seem to give a much longer life, it also has slots for high voltage protection. 

The probes supplied with the U1241A seem to be better than the ones you had, they consist of a banana plug lead which plugs into a socket on the end of the probe. It also came with two sets of probes, one sharp one blunter.

It does share the same issues with continuity speed which I was disappointed with as even my old UNI-T meter is much faster.  I've now had two U1241A's (I returned the first) as the stand is crooked when laid flat, and it been the same in both that I've had which is a bit annoying.

Despite the shortcomings I think that these are very good value meters especially at the lower end of the range as accuracy wise it gives something nearer to the fluke 87 for nearer the price of the fluke 179. Maybe some of the issues I mentioned being different will have changed in the new version.
 

Offline Ferroto

  • Frequent Contributor
  • **
  • Posts: 289
  • Country: ca
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #1 on: January 24, 2010, 03:26:58 pm »
I wouldn't have given that product a thumbs up. I can excuse the placement of the fuses, the display only working indoors, the annoying music, the rechargeable 9v battery But the cold solder joint you showed us isn't consistent with something I'd be willing to pay up to $400 for. I'm quite shocked that Agilent would field this product as it is hopefully the next model isn't this bad.
 

Offline cybergibbons

  • Frequent Contributor
  • **
  • Posts: 400
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #2 on: January 24, 2010, 11:44:41 pm »
I was looking at getting one of this range, but the review has really turned me off the meter. Main reason being the slow autoranging and slow continuity beep. These are the kind of thing that would wind me up day after day. Maybe they'll fix it in the next revision.

Also, there's niggling things. The poor solder joint should have been caught by QC on a product this expensive. I wouldn't really trust a meter to hold accuracy if it was like this. Why make the fuses so hard to access? Why not make a bit more of the dot-matrix display?
 

Offline dc100GHz

  • Newbie
  • Posts: 3
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #3 on: January 25, 2010, 05:52:42 am »
Cold solder is a deal breaker. I'd expect a better QC for a $400 multimeter.

If HP were still around they would design a multimeter that could compete with Fluke. But ever since Agilent took over, they killed the HP way, and outsourced production and design.
 

Online Zero999

  • Super Contributor
  • ***
  • Posts: 19345
  • Country: gb
  • 0999
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #4 on: January 25, 2010, 02:15:23 pm »
Yes, it's probably made in China as everything is. It doesn't seem like we have a choice nowadays when even so-called high-end stuff is still poor quality.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #5 on: January 25, 2010, 09:54:48 pm »
Well, it looks like I've created a furore with my "thumbs up" rating in this blog!
So many emails, comments, and even a video response.
There might have to be a follow-up video on this!

Dave.

 

Offline qno

  • Frequent Contributor
  • **
  • Posts: 422
  • Country: nl
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #6 on: January 27, 2010, 08:13:40 pm »
Hi Dave,

Congratulations on your review.
I have a bit mixed feelings. I wanted the Agilent to be good and at least in the Gossen class equipment.
I have used HP equipment for many years and they earned my respect.

However some aspects of this meter are a bit disappointing.
I have a feeling that different design principles have been used at Agilent than when it was HP.
The NEC processor is a tell tale sign where the design came from.
I hear the same about the oscilloscopes I have evaluated a 3000 series and was not really impresses with the UI.

Lets hope they fix some of the issues in the B version and have the top model also with an LCD.
 

Why spend money I don't have on things I don't need to impress people I don't like?
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #7 on: January 27, 2010, 09:00:55 pm »
Hi Dave,

Congratulations on your review.
I have a bit mixed feelings. I wanted the Agilent to be good and at least in the Gossen class equipment.
I have used HP equipment for many years and they earned my respect.

However some aspects of this meter are a bit disappointing.
I have a feeling that different design principles have been used at Agilent than when it was HP.
The NEC processor is a tell tale sign where the design came from.
I hear the same about the oscilloscopes I have evaluated a 3000 series and was not really impresses with the UI.

The 3000 series Agilent oscilloscope is just a rebadged Rigol. The 6000 series and up on the other hand is Agilent design, and that really shows, that's one of my favorite scopes.

Yes, I agree the Agilent is disappointing in a few areas, they need to work on it. It is a not suitable as a mainstream everyday use multimeter.

Dave.
 

Offline jahonen

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: fi
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #8 on: January 28, 2010, 12:28:46 pm »
I believe Agilent has been relatively recently expanding their low-end product range. When they were part of HP, they primarily made their products for those customers who weren't interested of the price tag (or if you must ask the price, then it is too expensive for you).

They are probably focusing their in-house designs at high-end market where they can be competitive, and outsourcing the rest.

Regards,
Janne
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #9 on: January 28, 2010, 09:16:45 pm »
Yes, they bought Escort, so that's the group that is producing a lot of Agilents low end handheld stuff now I believe.
 

Offline Veramacor

  • Regular Contributor
  • *
  • Posts: 111
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #10 on: January 28, 2010, 10:45:14 pm »
Let's see,

The main page clearly states the following in the first sentence...

"The EEVblog is an off-the-cuff video blog and Podcast of interest to anyone involved in electronics design."

Off-the-cuff.    The definitions for 'Off the cuff' that best describe what Dave is doing are:

"an impromptu speech"
"a few unrehearsed comments"

After watching Dave and his podcasts, does anyone really think that he planned and rehearsed to say things like:

"It was like I was being mooned!" (on opening the Agilent and seeing the back side of board first)
"Someone at Agilent should be shot!" (on Agilent's short battery life)

Dave is speaking to a camera in an impromptu manner.  Whatever comes to his mind about the subject at hand is obvious.  

You can't get put off by the negative comments Dave makes about the reviewed products.  They are extremely helpful in deciding if its the product for you.  If the positive outweighs the negative for YOUR needs,  then the product "is the shit!".  If it's the other way around, then "its a piece of shit!".

If you want polished reviews of products, go to Consumer Reports.  If you want NO BULLSHIT points of view and opinion,  Watch Dave.

Come on now!  I bought the reviewed Rigol Oscilloscope Dave reviewed:

* without ever seeing one in person
* without being able to touch one in person
* relying it would get here in one piece from China

$400, that's how much I spent.  Never would have sent my money to China if it were not for Dave's invaluable reviews.  I was  >   <  close to buying a PC USB digital o-scope.  Cheaper by far than the real thing.  But Dave's review on PC DSO's changed my mind.  I made the right decision.

One thing about blogs,  doesn't matter the subject,  There is always a pissing match eventually.  


EEVBLOG = VALUE.    nuff said.
« Last Edit: January 28, 2010, 10:52:19 pm by Veramacor »
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #11 on: January 29, 2010, 02:05:38 am »
One thing about blogs,  doesn't matter the subject,  There is always a pissing match eventually.  

Ain't that the truth!
If there is one thing I've learned with this blog (and all my forum stuff over the years) is that you can't even please a minority, so it ain't worth trying.
Publish and be damned!

Normally I ignore the trolls, but this time a few regulars (whose comments I take seriously) had concerns so that's why I thought I'd try and clear it up.

And I think it's great when someone like Stormbytes has the guts to produce a video response, rather than just pissing in the wind with anonymous comments. That alone deserved a response.

Dave.
 

Offline shawn01

  • Newbie
  • Posts: 5
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #12 on: January 30, 2010, 08:11:48 am »
I noticed on the agilent website …

An 8 hour battery life for the u1251b……. What if this meter has to serve 3 shifts of employees round the clock… apparently it was designed for the hobbyist. It appears there is no power supply for the meter that will provide the user with power in the event of a battery shortage                                                                                                                                                                                                                                             

One solution for someone who has their sights set on the u1252 is to buy the meter for the 50000 count/.accuracy, and solder an external supply in to the battery compartment.
Although This is being cheap and relationships with data acquisition tools that start out that way are normally hell bent on disaster, this could be a good workaround if you already have one.. 

Or you could get a 50000 count bench meter between 4x and 5x more $ that can be  plugged into the wall. 
 

Andrew

  • Guest
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #13 on: January 30, 2010, 08:48:05 am »
One solution for someone who has their sights set on the u1252 is to buy the meter for the 50000 count/.accuracy, and solder an external supply in to the battery compartment.
Although This is being cheap and relationships with data acquisition tools that start out that way are normally hell bent on disaster, this could be a good workaround if you already have one..  

I don't know for whom Agilent designed the meter, apparently not for me. I wouldn't buy it, and that would be the end of the story for me. No need to get excited or agitated. Thousands of companies produce products every day that are simply not my cup of tea.

I would recommend against "fixing" the meter by soldering an external supply to the battery compartment. This breaks the isolation and you can forget about the 600 V or 1000 V CAT safety rating. In my book breaking safety is fare more worse than ridiculous battery lifetime, and in the particular case perverts the idea of "buying brand", aka paying for safety as kind of a life insurance.

Quote

Or you could get a 50000 count bench meter between 4x and 5x more $ that can be  plugged into the wall.  

No, even an brand bench meter like one from Agilent ;) would just set you back 450 USD (U3401A). More 1x times the price of the U1252A, than 4x times the price. A *cough* Mastech MS8050 *couch* would set you back $250 (don't take this as a recommendation).

« Last Edit: January 30, 2010, 09:42:13 am by Andrew »
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #14 on: January 30, 2010, 09:53:38 pm »
I noticed on the agilent website …

An 8 hour battery life for the u1251b……. What if this meter has to serve 3 shifts of employees round the clock… apparently it was designed for the hobbyist. It appears there is no power supply for the meter that will provide the user with power in the event of a battery shortage                                                                                                                                                                                                 

The U1251A is 72 hours battery life, not 8, I believe the B model is the same.

The U1253A was not designed for the hobbyist, it was designed for professionals who need an accurate 50000 count meter with bright OLED display.
The U1252A is the exact same thing for those who want an LCD display and longer battery life
The U1251A is slightly lower spec with double the battery life again.

No point arguing silly "what if" scenario's, you buy the appropriate meter for the job at hand. IMO none of these meters would be suitable for 3 shift round the clock use.

Dave.
 

Offline jahonen

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: fi
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #15 on: January 31, 2010, 10:07:55 am »
Not all Flukes are much better either on the battery life, my Fluke 89IV has 72 hours of battery life (according to the manual), and it uses 4 AA's! Well, at least it does not rattle and the fuses are easily accessible in the battery compartment :)

Regards,
Janne
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #16 on: January 31, 2010, 11:42:02 am »
Not all Flukes are much better either on the battery life, my Fluke 89IV has 72 hours of battery life (according to the manual), and it uses 4 AA's!

Yes, the equivalent precision high end Fluke's have roughly equivalent power consumption to the Agilents (when you take into account display and battery type), they just sensibly use a lot of AA's instead of a silly 9V battery.

Dave.
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 17728
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #17 on: February 02, 2010, 06:12:54 pm »
I can see the thumbs up side for this meter it certainly look like a stunny peice of kit precision wise the sort of thing you would keep in the lab as the god of all meters and "the one" when it comes to ultimate accuracy, but it should be pointed out that this is about the only use this meter may ever have. I'd certainly not want to be carrying it around with me.

I think that on the protective holder they kind of missed the point, yes I hate those holders but hey they wouldsave the meter if dropped out on a hard surface, even my cheapo crap chinese meter has a well fitting and decent looking holster, in fact better than flukes, Agilent kind of missed the point with those "bits" yes it looks sleekeer but for something with that accuracy I'd want more protection unless ? I'm going to frame the damn thing and never touch it.
 

Offline TopherTheME

  • Regular Contributor
  • *
  • Posts: 196
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #18 on: July 28, 2010, 01:55:31 am »
Hello. Long time viewer, first time poster. I know this is an old thread but I just picked up one of Agilents newer B models, the u1242B. Not the equivalent of the u1253B but with all the controversy over the u1253A, I thought I would post some a mini review of it anyway to show some of the improvements Agilent has made.

Here's a quick overview of the features that I think make this meter special:
-300h battery life with 4 AAA batts
-Harmonic ratio measurement
-Manual and automatic data logging (to the meter ONLY)
-Dual temperature probe measurement
-Switch counter
-Comes with two sets of probes and one set of test leads (very high quality)
-$220 price tag (I got mine for $200 w/coupon)

So of course, before I even turned the thing on I had to take it apart.



The case is held together using four machine screws that thread into metal inserts. (thumbs up!) First things I noticed was the isolated input PCB and the IR LEDs. The higher up model DMMs that Agilent offers (u125XB) offers the ability of PC communication using a IR USB cable while the u124XB series supposedly does not. Why it has IR LEDs in it, I don't know. Maybe for calibration or something. Anyway, almost all components are SMT except for a few through hole parts including a large sized 2.4576M crystal. Everything looks to be very high quality and fairly well laid out. The back panel is almost entirely shielded and includes a separate compartment for the batteries but not the fuses.



The input plugs are soldered directly onto their own PCB and connect to the main PCB via small aluminum (I think?) standoffs. The 10A input port has a small 2-pin header connected to which plugs into the main PCB as well. I'm guessing its for lead detection. The banana jacks have o-rings around them for sealing. One thing to note is that the case itself does not contain any o-rings or seals.



A pic with the input PCB removed.



Heres the other side of the board where you can now see all the input protection components and stupid fuse placement. Notice the shiny looking shunt resistor for 10A current measurement.



Heres a pic of the bottom side with the screen taken off showing the main uC. The die reads "Samsung C011, 38825AXZZ-TW8A, K4X890. Yeah, I had no idea Samsung did uCs like this either. I'm guessing its an ASIC of some sort.



And the last pic is of the window for the two IR communication LEDs. If the meter contains two IR LEDs I really don't understand why Agilent would not allow the use of connecting these things to a PC. Seems kind of stupid to me.


In summary my opinion of the u1242B in a single paragraph:
From first impressions, it looks to be a really nice meter. It obviously doesn't have any of the major pitfalls of the u1253A like short battery life (300h w/4 AAAs) or a display you can't see outside. The display is very clear and easy to read and the orange backlight makes it very easy to read even at high angles. There are still a few quarks that carry over from the A series such as the slow response continuity check but voltage, resistance, and capacitance readings are all fairly quick. The case does leave a little bit to be desired as its obviously not as rugged as a Fluke 87 but I work (and play) in a lab setting so thats not a big deal for me. The main selling points for me were that I wanted a good accurate meter that I could rely on which also had the ability to log data in the field (I do a lot of fuel cell, solar, and battery stuff) and do dual temperature measurement. With the exception of the chinese pieces of crap that claim a BS accuracy, this is the meter I liked best given my $200 budget.



« Last Edit: July 28, 2010, 02:21:32 am by TopherTheME »
Don't blame me. I'm the mechanical engineer.
 

Offline TopherTheME

  • Regular Contributor
  • *
  • Posts: 196
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #19 on: July 28, 2010, 02:16:49 am »
Forgot to add that Agilent included these multimeter skins that you can stick onto these things. I chose the gogreen one to match my hippie personality.

Don't blame me. I'm the mechanical engineer.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #20 on: July 28, 2010, 04:50:45 am »
Awesome work, thanks for the pics and breakdown.
Looks like a really great meter, shame about the still slow continuity buzzer.
Layout looks pretty good apart form the underside fuse which is just plan silly.

Looks like awesome value for $200.

Did it come with a cal certificate?

Dave.
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #21 on: July 28, 2010, 10:24:10 am »
Great job, and thanks for posting pics. :D
Best Wishes,

 Saturation
 

Offline TopherTheME

  • Regular Contributor
  • *
  • Posts: 196
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #22 on: July 28, 2010, 12:19:38 pm »
Did it come with a cal certificate?

Yes. It comes with a signed certificate of calibration from Agilent which includes the data and readings from the calibration process. I think for about $50 more you can get a cal certificate from NIST.
« Last Edit: July 28, 2010, 12:24:52 pm by TopherTheME »
Don't blame me. I'm the mechanical engineer.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #23 on: July 28, 2010, 12:31:16 pm »
Is there any reason they put the 11A fuse on the bottom?
Can it be desoldered and moved to the top?  ;D

Dave.
 

Offline safarir

  • Regular Contributor
  • *
  • Posts: 80
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #24 on: July 28, 2010, 11:37:32 pm »
Hey guys,

I just receive my u1252B after 3 month of wait. The big suprise: Every board (3) have a u1251 silkcreen on it.

Maybe the u1251B can be hack to the u1252B...

The bad new: The windows as a big bubble in the center  >:( and now that I take it appart, the rotary switch don't fell as good as when it was new.
« Last Edit: July 28, 2010, 11:48:46 pm by safarir »
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #25 on: July 29, 2010, 01:10:20 am »
can you take a big picture, what is this 'big bubble'?

If the rotary switch feels different, it might pay to open it again and check that its seated properly.



Hey guys,

I just receive my u1252B after 3 month of wait. The big suprise: Every board (3) have a u1251 silkcreen on it.

Maybe the u1251B can be hack to the u1252B...

The bad new: The windows as a big bubble in the center  >:( and now that I take it appart, the rotary switch don't fell as good as when it was new.
Best Wishes,

 Saturation
 

Offline safarir

  • Regular Contributor
  • *
  • Posts: 80
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #26 on: July 29, 2010, 01:58:10 am »
I already reopen it 2 time but it probably in my head...

The "big bubble" is in fact pretty small (2mm diameter), just enough to scrap my joy but I will probably keep it like that...
« Last Edit: July 29, 2010, 02:01:03 am by safarir »
 

Offline orbiter

  • Frequent Contributor
  • **
  • Posts: 619
  • Country: gb
  • -0 Resistance is Futile
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #27 on: August 01, 2010, 10:48:45 am »
I already reopen it 2 time but it probably in my head...

The "big bubble" is in fact pretty small (2mm diameter), just enough to scrap my joy but I will probably keep it like that...

Are you sure it's not another screen protection sheet with a trapped air bubble below it? My U1252B meter came with two plastic screen covers. The first was a larger thicker peel-off type plastic sheet, with a much thinner peel-off sheet below it. I only noticed the very thin sheet as mine also had a small bubble underneath it.

orbiter
« Last Edit: August 01, 2010, 10:51:30 am by orbiter »
 

Offline safarir

  • Regular Contributor
  • *
  • Posts: 80
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #28 on: August 05, 2010, 10:58:43 am »
I already reopen it 2 time but it probably in my head...

The "big bubble" is in fact pretty small (2mm diameter), just enough to scrap my joy but I will probably keep it like that...

Are you sure it's not another screen protection sheet with a trapped air bubble below it? My U1252B meter came with two plastic screen covers. The first was a larger thicker peel-off type plastic sheet, with a much thinner peel-off sheet below it. I only noticed the very thin sheet as mine also had a small bubble underneath it.

orbiter

After a closer look, I think you are right
 

Offline spackard

  • Newbie
  • Posts: 8
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #29 on: August 06, 2010, 05:04:13 pm »
Since this thread was woken up again I just wanted to mention I bought a U1253A several months ago based primarily on Dave's review of it.  I didn't really need another DMM (I have bought a few over the decades) but when a U1253A came up on EBay for cheap I went for it.

Two things:
1)  Dave's review briefly mentioned how quick this meter is to take a measurement and lock into a correct reading, but I didn't realize how quick it really is until I used it.  It's very impressive!  I hit the circuit with the probes and bang! it's made up its mind what the voltage is and its opinion doesn't change.  It's much quicker than my other meters.  It's really something to see in person!

2)  In practice I don't find the continuity check to be slow.  I was ohm'ing out a dead microwave and thinking I'd have to be cautious with probing then waiting for the meter to beep, but I quickly learned I can go as fast as I want along a circuit.  It did seem strange that if all I was doing was touching and releasing the probes in my hands I could get a bit of slowness from the meter, but that doesn't happen when probing actual circuits.

The microwave:  It ended up being an open winding on the primary side of the transformer for the circuit board electronics (it was the small transformer, not the big inverter transformer).  I thought this was very strange, as I thought components downstream of a transformer would blow long before a winding on a transformer itself.  Nevertheless, that's what it was.  I replaced only the transformer and the microwave worked fine again.

The microwave had been plugged into a branch circuit that the homeowner had been having problems with for several months, and a few microwave ovens before this had gone bad after a few months of use.  They called me when the branch circuit finally got bad enough their refrigerator would not run when plugged into a socket on the branch.  I traced the source of that problem too (using the U1253A though any general-purpose DMM would have worked).  It was an open neutral on a multiwire branch circuit (I should mention I'm from the United States so these electrician terms may be different in .au).  You can see a good Powerpoint presentation of what happens to the voltages on such a broken circuit here if you're interested:  http://www.code-elec.com/userimages/Lost Neutral.ppt

I found:
a) all the neutrals from two branches were not pre-twisted together (some people disagree if pre-twisting is necessary; I think it is).
b) the wire nut was not on tight at all.  The straight exposed copper shafts from the stripped neutrals were just barely touching each other.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #30 on: August 06, 2010, 10:57:26 pm »
Since this thread was woken up again I just wanted to mention I bought a U1253A several months ago based primarily on Dave's review of it.  I didn't really need another DMM (I have bought a few over the decades) but when a U1253A came up on EBay for cheap I went for it.

Two things:
1)  Dave's review briefly mentioned how quick this meter is to take a measurement and lock into a correct reading, but I didn't realize how quick it really is until I used it.  It's very impressive!  I hit the circuit with the probes and bang! it's made up its mind what the voltage is and its opinion doesn't change.  It's much quicker than my other meters.  It's really something to see in person!

And to think every kicked up a real stink about me liking this meter!

Dave.
 

Offline PetrosA

  • Frequent Contributor
  • **
  • Posts: 625
  • Country: us
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #31 on: August 07, 2010, 02:17:25 am »
The microwave had been plugged into a branch circuit that the homeowner had been having problems with for several months, and a few microwave ovens before this had gone bad after a few months of use.  They called me when the branch circuit finally got bad enough their refrigerator would not run when plugged into a socket on the branch.  I traced the source of that problem too (using the U1253A though any general-purpose DMM would have worked).  It was an open neutral on a multiwire branch circuit (I should mention I'm from the United States so these electrician terms may be different in .au).  You can see a good Powerpoint presentation of what happens to the voltages on such a broken circuit here if you're interested:  http://www.code-elec.com/userimages/Lost Neutral.ppt

I found:
a) all the neutrals from two branches were not pre-twisted together (some people disagree if pre-twisting is necessary; I think it is).
b) the wire nut was not on tight at all.  The straight exposed copper shafts from the stripped neutrals were just barely touching each other.



That's some good sleuthing (a lot of electricians have a really hard time figuring out shared neutrals). So I understand you're an electrician and an appliance repair person all-in-one? That's pretty rare. We should also explain what a wire nut is since they don't use them in most other countries - to make a splice, you twist the wires together in a clockwise motion and then twist a wirenut on which is an insulated spring type device that narrows towards the tip. As you screw it on to the twisted wires, it clamps down tight and makes a very solid splice when used correctly. As far a pre-twisting, many wirenuts nowadays are designed so you don't need to twist the wires with a pair of pliers first, but you DO need to twist very hard for the wirenut to do the twisting. Some guys just don't get that part of the instructions ;)

Edit to add photo of wirenuts in action:
« Last Edit: August 07, 2010, 04:00:53 am by PetrosA »
I miss my home I miss my porch, porch
 

Offline cybergibbons

  • Frequent Contributor
  • **
  • Posts: 400
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #32 on: August 07, 2010, 04:27:46 am »
It amazes me how different mains wiring standards are between the US and UK.

I've worked with both systems, and it does seem that wire nuts are more prone to user error than the terminal blocks used in the UK. You've also got the complication of having two phases, and hence problems like the one mentioned!
 

Offline squeezee

  • Contributor
  • Posts: 47
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #33 on: August 07, 2010, 01:18:47 pm »
Hmm i don't know if anyone noticed this, but the (now discontinued) BK Precision 2890A looks to be the same basic meter as the agilent U1252.
 

Offline saturation

  • Super Contributor
  • ***
  • Posts: 4787
  • Country: us
  • Doveryai, no proveryai
    • NIST
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #34 on: August 07, 2010, 03:04:58 pm »
Its likely an Escort designed DMM with a B&K brand.  Agilent bought Escort in 2008 and now use their technology in their DMMs.  They have similar keys with a different layout and screen, but Agilent's own data strongly suggests they are identical, but you'd have to compare function for function on the Escort to be sure.

Sorry for big photos, but the details show far more clearly.

Cross referencing Escort DMMs with Agilents:

http://www.home.agilent.com/agilent/editorial.jspx?ckey=1441000&id=1441000&nid=-536902435.0.00&lc=ger&cc=DE


 
On some of the acquisitions, Agilent didn't bother change the design at all, just the name:






Hmm i don't know if anyone noticed this, but the (now discontinued) BK Precision 2890A looks to be the same basic meter as the agilent U1252.
Best Wishes,

 Saturation
 

Offline PetrosA

  • Frequent Contributor
  • **
  • Posts: 625
  • Country: us
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #35 on: August 07, 2010, 04:15:31 pm »
It amazes me how different mains wiring standards are between the US and UK.

I've worked with both systems, and it does seem that wire nuts are more prone to user error than the terminal blocks used in the UK. You've also got the complication of having two phases, and hence problems like the one mentioned!

There are some pretty big differences, for sure! I really like the terminal blocks used outside the US and I use them here for many things (we can get them, but most guys don't think to use them). The shared neutral works in a three phase wye system as well but I didn't do enough electrical work during my stay in Poland to know whether they use it on branch circuits in industrial systems or not beyond the shared neutral in the feeder. The math works out a little differently in three phase, so you have to share the neutral between all three phases to cancel out the load obviously. The photo I posted shows shared neutrals in a three phase system here and you might be able to make out that I bundled the three phases and their neutral on the incoming wires to keep things safe.
I miss my home I miss my porch, porch
 

Offline squeezee

  • Contributor
  • Posts: 47
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #36 on: August 07, 2010, 04:44:59 pm »
Its likely an Escort designed DMM with a B&K brand.  Agilent bought Escort in 2008 and now use their technology in their DMMs.  They have similar keys with a different layout and screen, but Agilent's own data strongly suggests they are identical, but you'd have to compare function for function on the Escort to be sure.
Ah good information, I figured it was rebranded from someone else. Likely explains some of the odd design decisions in the Agilent meters, being carried over from Escort rather than a new ground-up design by Agilent.

I mention the BK since i've seen a few pop up new for a bit over half the price of the U1252A; Just thinking it might be a good deal to jump on one of them.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 37664
  • Country: au
    • EEVblog
Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #37 on: August 07, 2010, 10:46:22 pm »
Its likely an Escort designed DMM with a B&K brand.  Agilent bought Escort in 2008 and now use their technology in their DMMs.  They have similar keys with a different layout and screen, but Agilent's own data strongly suggests they are identical, but you'd have to compare function for function on the Escort to be sure.
Ah good information, I figured it was rebranded from someone else. Likely explains some of the odd design decisions in the Agilent meters, being carried over from Escort rather than a new ground-up design by Agilent.

I mention the BK since i've seen a few pop up new for a bit over half the price of the U1252A; Just thinking it might be a good deal to jump on one of them.

Escort used to be a third party designs house that sold rebadged gear to everyone, including Agilent and BK Precison. But since Agilent bought Escort and used it to form their new low cost instrument group out of Malaysia, BK Precision can no longer get updates to these products. But they are allowed to continue to sell and modify the the old design. That is why the new BK Precision LCR meter I have is a new design to the Agilent/Escort one.

Dave.
 




Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf