Author Topic: EEVblog #56 – Agilent U1253A OLED Multimeter Review  (Read 24014 times)

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Offline saturation

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #25 on: July 29, 2010, 11:10:20 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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #26 on: July 29, 2010, 11:58:10 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, 12:01:03 pm by safarir »
 

Offline orbiter

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #27 on: August 01, 2010, 08:48:45 pm »
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, 08:51:30 pm by orbiter »
 

Offline safarir

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #28 on: August 05, 2010, 08:58:43 pm »
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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #29 on: August 07, 2010, 03:04:13 am »
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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #30 on: August 07, 2010, 08:57:26 am »
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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #31 on: August 07, 2010, 12:17:25 pm »
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, 02:00:53 pm by PetrosA »
I miss my home I miss my porch, porch
 

Offline cybergibbons

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #32 on: August 07, 2010, 02:27:46 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!
 

Offline squeezee

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #33 on: August 07, 2010, 11:18:47 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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #34 on: August 08, 2010, 01:04:58 am »
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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #35 on: August 08, 2010, 02:15:31 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!

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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #36 on: August 08, 2010, 02:44:59 am »
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

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Re: EEVblog #56 – Agilent U1253A OLED Multimeter Review
« Reply #37 on: August 08, 2010, 08:46:22 am »
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.
 




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