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Author Topic: Ideal 61-481 Multimeter teardown.  (Read 4603 times)

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Offline Robomeds

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Ideal 61-481 Multimeter teardown.
« on: June 20, 2013, 02:33:00 PM »
True RMS meter with the usual plus frequency and RPM display and capacitance.  Buttons for hold, min/max, range and function.  About the same size as a Fluke 87 but a bit lighter. 
I picked this thing up recently for $9.  It was described as powering on but not taking readings.  I figured I would take a look and worst case have a spare set of leads.  So here is my quick review and tear down.  Note: I only did the most rudimentary testing and nothing that I would call accuracy testing.  The closest I got was comparing to a Fluke 77-3 to make sure the readings were at least on the same page. 
Starting with the readings.  The volts DC, resistance and current DC all seemed to agree with my Fluke within the range of the specs.  I had to bypass the blown fuses to get a current reading and only checked at ~100mA.  The bar graph updates quickly, unlike some cheap meters which update the bar graph no faster than the digits.  The auto ranging is Fluke 87 quick and the continuity test is almost as good.  It’s latched and only slightly slower than the Fluke. 
The controls feel OK.  There is a bit of that plastic breaking feel to the switch but nothing too bad.  The display is dim even with a good battery.  The boot is of reasonable quality (similar to Extech) and the tiling stand is at least as stable as a Fluke 87-V (not great but usable).  Like most modern meters (and unlike the pre ‘V’ Fluke 87s) the boot is nicely integrated with the meter’s industrial design.  Certainly there is nothing embarrassing about the meter on the outside. 
The battery compartment is closed with a screw and metal insert.  You have to remove the boot to get to the battery.  The fuses are accessed by removing the 4 self-tapping screws in the back. 
Inside, well it’s no Fluke. 
The housing has the sort of overlapping grove between top and bottom housings that Dave talks about.  Nothing too substantial but perhaps 3mm worth.  The battery cover has a pocket which separates the battery from the PCB near the input terminals. 
Moving on to the circuit board we can see some of Dave’s items of interest.  It appears there are 2 PTCs and two spark gaps on the voltage input terminals.  The current terminals are (in theory) protected by the two fuses pictured.  Notice the black burn mark on the PCB near the fuse terminal.  That was caused by a flash over between a small trace to the switch and the inner fuse (the low current fuse). 
It’s clear this meter had a nasty shock one day.  In addition to the obvious failure of the fuse, we can see the spark induced damage to the PCB and nearby components.  There is also visual evidence that the locking washer which holds the terminals in was subjected to quite a bit of heat where it contacts the riser.  I recall Dave being less than impressed with the Ideal overload circuits during his $100 meter comparison.  This might add some fuel to that fire. 
Still, perhaps the most remarkable thing is that despite the abuse this meter actually still works and is delivering what appear to be accurate results.  I’m not going to bother paying to replace the fuses.  I’m not sure this meter is worth that much.  If I have to deal with anything high power (and I almost never do) my Fluke will be my go to meter.  I’m not sure how I feel about the safety of this meter in its current state.  The blacken gap doesn’t make me feel good but that’s still a 2+ mm gap and without the fuses no current is flowing through there anyway.  I guess I’m asking if people think this would make for a safe “leave it in the car” meter after this over current incident.
Anyway, hope everyone enjoyed the guts of another electronic toy .
Sorry for any typos. 
« Last Edit: June 27, 2013, 10:01:44 AM by Robomeds »
 

Offline c4757p

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Re: Idea 61-481 Multimeter teardown.
« Reply #1 on: June 20, 2013, 03:33:53 PM »
That's pretty sad-looking. Looks like C15 (the MLCC they bodged into the spot for an aluminum) may not even be soldered on both sides. And those poor transistors look like somebody sat on them after installing...
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline retiredcaps

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Re: Idea 61-481 Multimeter teardown.
« Reply #2 on: June 20, 2013, 03:42:07 PM »
I have a distinct feeling after seeing your multimeter collection, Fluke 8025B 99 cent win and this recent 99 cent win, that you and I and perhaps others here are looking at the same auctions.  Obviously you have a huge advantage over me since you live in the USA (your meter arrived in 2 days too).

Thanks for the mini review, teardown and pictures.

The Ideal meter is a rebadged Appa Tech 97 II.  See

http://www.appatech.com/upload/pdmodel/pdmodel_image113574197212790.jpg

http://www.appatech.com/upload/download/file113498332710938.PDF

I hope you get a few more low cost meters and continue to share the information as above.
« Last Edit: June 20, 2013, 04:23:17 PM by retiredcaps »
 

Offline Robomeds

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Re: Idea 61-481 Multimeter teardown.
« Reply #3 on: June 20, 2013, 09:03:48 PM »
Thanks, I was wondering who would have been the ODM for Ideal. 

Overall I think this meter would have done OK in Dave's $100 review except for the input protection and internal build.  On the outside it's well enough constructed.  It lacks a backlight which would have hurt but it has really fast auto ranging and continuity.  But, just like the Ideal in his review this one is lacking good spark gaps and blast shields.  I suspect I wouldn't own this one had it not been for those lacking features.

Anyway, I'll try a few more tear downs.  The one I really want to do is my Metrix/BK Precision meter.  It's the same model family as the Metrix intrinsically safe meter and certainly a high end type meter (50,000 count, IP667, AC+DC TRMS).  Sadly I think it's a snap together housing. 

 

Offline retiredcaps

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Re: Idea 61-481 Multimeter teardown.
« Reply #4 on: June 21, 2013, 08:11:21 AM »
Starting with the readings.  The volts DC, resistance and current DC all seemed to agree with my Fluke within the range of the specs.
If you feel like turning pots, the "technical manual" shows how.

http://www.worldeyecam.com/pdf/61-480.pdf
 

Offline Robomeds

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Re: Idea 61-481 Multimeter teardown.
« Reply #5 on: June 21, 2013, 12:36:00 PM »
Thanks, I think I will pass.  The thing seems in spec and what more do I need of it.  The fuses would cost me more than the meter!
 

Offline Robomeds

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Re: Ideal 61-481 Multimeter teardown.
« Reply #6 on: September 16, 2013, 11:44:08 PM »
Just a follow up post.  As Mr Modemhead says, this meter was being passed on to another forum member via Mr MH.  In searching for something else I recognized the pictures of my damage.  What a simple fix!
http://mrmodemhead.com/blog/ideal-carbon-footprint/

Happy to see the problem was fixed so readily.  I also learned something new. 
 


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