ISO-TECH (APPA) IDM105 DMM.

[firewalker]

Another cheap multimeter.

I bought for 10 euros an APPA 105 multimeter. The only reason for buying? It looked like a Fluke 87 and wanted to check it out.



You can exchange the rubber cases with no problem.



The rubber case feels and weighs like the Fluke's one. The plastic casing also gives you the impression that it is a really rugged multimeter. Metal threaded screws, o-ring for the case and the screws.



The inside though is another story. The construction is exactly what I was expected. No high voltage cut outs e.t.c.







It uses a JRC (Japan Radio Corporation) NJU9210F.





One thing I haven't seen before, is that the multimeter remembers the dual function key after you turn it off. If for example you choose the continuity test on the ohms rage it will default to continuity mode the next time you turn it on or change the position of the rotary switch. Also the dual function key is universal. If you select the second function for a position and you rotate the switch in a new place with a dual function it will default to the second function. Really annoying...

There is no back light, and the chip doesn't seem to have the option.

[voy]

Hi
 I now is far from date , but model appa on the picture is a fake . When i discavered this post i open my appa DMM - definitely its completely different inside like this one above . Crap review in my opinion . Thanks.

[retiredcaps]

Hi
 I now is far from date , but model appa on the picture is a fake . When i discavered this post i open my appa DMM - definitely its completely different inside like this one above . Crap review in my opinion . Thanks.

Rather than accuse someone who you don't know of photoshopping something and calling it a crap review, why don't you post pictures of your multimeter and supply a review?

You do know that manufacturers can make revisions and keep the same model number?

[firewalker]

This is not a review. It doesn't state anywhere that it is a review. It's just a tear down of a DMM. It would be great if someone provides pictures of another revision or the real one (if mine is fake one. I can ensure though that the pictures are not edited in any way apart from resizing).

Alexander.

[rsjsouza]

I am not 100% sure if I agree with the "complete crapiness" of this DMM, as it looks like a 20+ year old equipment (the datecode on the 4027 is 1990).
I have a 1987 Fluke 8060a and, despite the HRC fuse is inside its own plastic container on the Fluke, it is not terribly different than this one in terms of input protection, clearances, etc... I see there is a great deal of PCB space between the input jacks and the other circuitry.

[Wytnucls]

I don't see much wrong with this 4000 count meter either. Definitely not a fake, with decent protection and components on the board, like the Caddock 1776 voltage divider .
After a quick calibration, it should still give years of reliable service.
There is even space on the PCB for a proper 400mA HRC fuse and matching fuse holder.

[jucole]

It has a similar ring to my Appa 305.
https://www.eevblog.com/forum/reviews/iso-tech-305-dmm-%28under-the-hood%29/msg140262/#msg140262

[rsjsouza]

It has a similar ring to my Appa 305.

Call me old fashioned, but I absolutely love the bargraph in the shape of an arc of the DMMs shown in the other thread (Sanwa also has this). 

[firewalker]

It has a similar ring to my Appa 305.
https://www.eevblog.com/forum/reviews/iso-tech-305-dmm-%28under-the-hood%29/msg140262/#msg140262

Does this model have the same behavior with the dual functions?

Alexander.

[voy]

Hi
This is my ISO-TECH

[jucole]

It has a similar ring to my Appa 305.
https://www.eevblog.com/forum/reviews/iso-tech-305-dmm-%28under-the-hood%29/msg140262/#msg140262

Does this model have the same behavior with the dual functions?

Hi,  I've just checked on both my 305's and they both reset the dual function mode after the rotary switch is moved off the current selection.

[voy]

...I'm pretty sure - this one presented like idm105 on the top is Chinese copy.
Thanks

[jucole]

...I'm pretty sure - this one presented like idm105 on the top is Chinese copy.
Thanks

Voy - how can you tell?  please explain

[jucole]

I think the top one is just an older pcb version and Voy's ones is just a revised pcb revision.

[firewalker]

Or maybe vou's one is a fake.

Alexander.

[voy]

Jucole , maybe you right

[voy]

Hi Firewalker
Maybe is fake but better build like this one from you pictures 

[jucole]

Firewalker's is clearly marked as "105 1A" and in Voy's picture "IMG_0668.jpg"  it is marked "105N 2A" so although they are the same meter, they are clearly different, the date code on the chipset suggest Voy's is the later version as well.  Both very tweakable meters I might add,  when you read the chipset datasheet!

[voy]

..thanks  Jucole 
Now all is clear .