Amprobe AM-520 - A Peek Under the Hood

[SherlockOhms]

I just got this meter yesterday, I decided to go ahead and take a look inside. I'm pretty impressed. I'll be interested in hearing what the experts have to say about it.

[Wytnucls]

Is this one manufactured in China? I see a lot of similarities with the UNI-T61E.

[SherlockOhms]

Yes, made in China.

Link to the datasheet http://content.amprobe.com/DataSheets/AM520_DA_low.pdf
And the place I bought it from (no affiliation) http://www.testequipmentdepot.com/amprobe/multimeters/am-520.htm

[PedroDaGr8]

Yes, made in China.

Link to the datasheet http://content.amprobe.com/DataSheets/AM520_DA_low.pdf
And the place I bought it from (no affiliation) http://www.testequipmentdepot.com/amprobe/multimeters/am-520.htm

Yeah this has a lot in common with Uni-T meters.

A lot of things are in a similar location (crystall oscillator, the screws, the arrangement of the ports).
The company of the smd caps are the same (including some same values).
The battery holder is of the same design.
The PTC appears to be the same brand as my UT61E

Some bad things I notice:
One difference(between this one and my UT61E) is the soldering quality is actually worse on this one. Check VR1 and look at that nice little "tree branch" of solder coming off it.
The flying diode! That is a hazard all by itself.

I'm curious to see the other side of the board. To check out the main IC etc.

[SherlockOhms]

A few quick impressions -

DC and AC volts are on the same switch position and AC is the default, you have to hit the select button for DC. Minor annoyance for electronics tinkering.

The continuity check is very slow. I thought it was the probes at first, but better test leads don't really help.

Diode check will light up red, green, blue and white LEDs,  but only provides voltage reading for the red and green. Blue and white were 0L.

The non-contact voltage check seems to work well.  I rarely touch mains wiring, but this might be a nice double check for the once in a blue moon when I need to swap out a light switch or whatever.

Compared to a calibrated Fluke 27, the Amprobe is within 0.2% of it on Ohms and DC volts (all I've checked so far).  A 20k .01% resister measures 20.02 KOhms.

[FenderBender]

I'm curious to see the other side of the board. To check out the main IC etc.

Me too.

[PedroDaGr8]

Also I just noticed the outside says 10AMax on the A socket but the fuse is a Fluke 11A DMM fuse.

[T4P]

Fluke does the same thing and besides isn't amprobe owned by danaher?

[jarvis]

What's the main chip inside ?

[nanofrog]

Also I just noticed the outside says 10AMax on the A socket but the fuse is a Fluke 11A DMM fuse.

Agilent does the same as well.

Fluke does the same thing and besides isn't amprobe owned by danaher?

Yes.

[TorqueRanger]

I think I will be picking up a new meter soon hear but not sure if I would be better off with a used Fluke meter???

Would you guys change out the stock test lead or stick with them

[Lightages]

For $90 or less you can buy a new Amprobe AM-270 with the functions and safety for almost any job you might want to do as a hobbyist. At this point after seeing everything I have seen, I cannot think of a better deal for a multimeter right now. If I didn't have $90 to spend on a multimeter I would buy something like the UT33C at $15 and wait until I could afford the AM-270. The AM-530 looks really good too at $60 but the AM-270 is much more accurate.

[Wytnucls]

For $90 or less you can buy a new Amprobe AM-270 with the functions and safety for almost any job you might want to do as a hobbyist. At this point after seeing everything I have seen, I cannot think of a better deal for a multimeter right now. If I didn't have $90 to spend on a multimeter I would buy something like the UT33C at $15 and wait until I could afford the AM-270. The AM-530 looks really good too at $60 but the AM-270 is much more accurate.

The UT120C is also pretty good as a simple 4000 count pocket meter and it does mA/uA too, for $19.00 delivered.


http://dx.com/p/uni-t-ut120c-portable-1-8-lcd-digital-multimeter-grey-red-1-x-cr2032-152493

[zaoka]

Good luck with your new meter!

HIOKI 3804-50 is my best pick for $100, fastest reading speed (7 times per second), high accuracy, very good quality and trusted brand behind it.

[FenderBender]

For $90 or less you can buy a new Amprobe AM-270 with the functions and safety for almost any job you might want to do as a hobbyist. At this point after seeing everything I have seen, I cannot think of a better deal for a multimeter right now. If I didn't have $90 to spend on a multimeter I would buy something like the UT33C at $15 and wait until I could afford the AM-270. The AM-530 looks really good too at $60 but the AM-270 is much more accurate.

The UT120C is also pretty good as a simple 4000 count pocket meter and it does mA/uA too, for $19.00 delivered.


http://dx.com/p/uni-t-ut120c-portable-1-8-lcd-digital-multimeter-grey-red-1-x-cr2032-152493

I always find it interesting when a product flaunts the CE mark like its such a remarkable accomplishment. Haha. All jokes aside, it could be a good meter.

[Bored@Work]

I always find it interesting when a product flaunts the CE mark like its such a remarkable accomplishment. Haha.

As long as people believe the CE mark means anything manufacturers will parade it around.

Interestingly, didn't Uni-Trend say Europe is not a market they care about? So why don't they save the ink?

[unbiased]

I know this thread is somewhat old but I am new to the forums (just joined) and saw this thread titled for an Amprobe AM-520 Tear Down but in every title of every post it says "Amprobe AM-530 Tear Down"!  How's that? 
So I figured, I'd help y'all out and show you the insides of the real AM-530 DMM which I just purchased from amazon.com.  From the looks of it, the build is very similar to the AM-520 except for some improvements. For one, the battery screw is not a self tapping into plastic screw but a full metal insert anchored screw.  Various PCB runs and component parts layouts are a bit different too. 
I bought this AM-530 after returning an Extech EX-430 in search of a new decent multimeter.  I like this meter, but I wanted more resolution, so now I just ordered a Brymen BM869 instead.  I still plan on keeping this AM-530 though.  It seems like a well built and sturdy meter.  Just a bit slow in polling cycles for my tastes but will serve most purposes I will use it for.
Anyway, here's the insides of the Amprobe AM-530 for reference:

[P90]

I know this thread is somewhat old but I am new to the forums (just joined) and saw this thread titled for an Amprobe AM-520 Tear Down but in every title of every post it says "Amprobe AM-530 Tear Down"!  How's that? 
So I figured, I'd help y'all out and show you the insides of the real AM-530 DMM which I just purchased from amazon.com.  From the looks of it, the build is very similar to the AM-520 except for some improvements. For one, the battery screw is not a self tapping into plastic screw but a full metal insert anchored screw.  Various PCB runs and component parts layouts are a bit different too. 
I bought this AM-530 after returning an Extech EX-430 in search of a new decent multimeter.  I like this meter, but I wanted more resolution, so now I just ordered a Brymen BM869 instead.  I still plan on keeping this AM-530 though.  It seems like a well built and sturdy meter.  Just a bit slow in polling cycles for my tastes but will serve most purposes I will use it for.
Anyway, here's the insides of the Amprobe AM-530 for reference:

That diode above the ma fuse, in the second pic looks goofy! 

[unbiased]

Yeah, I personally am not that anal about such discrete mounted components. It does not affect overall operation one bit. I agree that the way the diode is mounted crooked and all does make it appear a sloppy though.  I know eevblog Dave usually frowns on seeing such components mounted on a surface mount PC board design but really it does not affect the overall performance of the circuit for the most part in these meters (unless you are dealing with very high frequencies where stray capacitance and component placements and trace leads matter).  But this diode I am sure won't make a darn in changing accuracy or performance of the meter.  The meter works great for its price point.  However with all that said, I have to say I had returned this meter back to Amazon.com for a refund because it I had noticed that the AM-530 model that they advertised on their website picture is an updated more current model with different front panel layout and higher CAT ratings!  The one I got looks like the old style model with lower CAT ratings and less function switch selections (no battery test selectors).  So I did not get what was advertised and figured maybe Amprobe has a newer revision of it... or that Amazon.com posted a fake or wrong picture of a prototype AM-530?  Anyway, since I got a Brymen BM-869 and a new Greenlee DM-830A (which is a rebadged Brymen BM-829S), I don't really need the old Amprobe AM-530 really.  Too many multimeters in my tool box.  But I can say the Amprobe AM-530 performed really well and is much cheaper than the higher end meters I wound up settling on.

[Wytnucls]

Gossen is not averse to some through-hole tweaking either, even on one of their most expensive meters.

[P90]

Yeah, I personally am not that anal about such discrete mounted components. It does not affect overall operation one bit. I agree that the way the diode is mounted crooked and all does make it appear a sloppy though.  I know eevblog Dave usually frowns on seeing such components mounted on a surface mount PC board design but really it does not affect the overall performance of the circuit for the most part in these meters (unless you are dealing with very high frequencies where stray capacitance and component placements and trace leads matter).  But this diode I am sure won't make a darn in changing accuracy or performance of the meter.  The meter works great for its price point.  However with all that said, I have to say I had returned this meter back to Amazon.com for a refund because it I had noticed that the AM-530 model that they advertised on their website picture is an updated more current model with different front panel layout and higher CAT ratings!  The one I got looks like the old style model with lower CAT ratings and less function switch selections (no battery test selectors).  So I did not get what was advertised and figured maybe Amprobe has a newer revision of it... or that Amazon.com posted a fake or wrong picture of a prototype AM-530?  Anyway, since I got a Brymen BM-869 and a new Greenlee DM-830A (which is a rebadged Brymen BM-829S), I don't really need the old Amprobe AM-530 really.  Too many multimeters in my tool box.  But I can say the Amprobe AM-530 performed really well and is much cheaper than the higher end meters I wound up settling on.

Is that even possible?     

[P90]

Gossen is not averse to some through-hole tweaking either, even on one of their most expensive meters.

Wow, now that's interesting...   

[VK5RC]

I can hear the design engineer, just after the production run has started,  'why didn't board design 3.2 get through,  oh f...'  His mates ribbed him for weeks!