Canadian Tire Mastercraft DMM New and old revision teardown

[retiredcaps]

DTM0660L

Thanks for that information and your comments.  If I didn't already have more meters than I need/want, I probably would have picked one of these up.  Maybe next time when it goes on sale again, I might be tempted again.  I'm a sucker for multimeters that use AA or AAA cells. 

[Paul Moir]

Yeah, well when you're knee deep in yellow meters, why would you look around for something else? 

[retiredcaps]

Yeah, well when you're knee deep in yellow meters, why would you look around for something else? 

Well, macboy made a convincing argument.  The other reason for getting one is I only recommend meters that I have used or own.  I can't honestly tell people to buy one if I don't have any hands on experience as I mentioned in post #11.

Well, this is currently (to end of today) on sale for $25 CDN so I thought maybe I'd buy one. Then I thought, the last thing I need is another multimeter. So I bought one.

[Paul Moir]

Yeah, I see your point. 
I also don't want to seem like I'm coming down from Mt Sinai with this thing here either.  I think you can get a UT-61E for only a few bucks more than the normal price of this meter, and I think they finally got around to responsible CAT ratings and what not?  Never mind the greater functionality.  This thing is a nasty cheap meter.  But it's got it's moments, is c/UL/US approved, and at $25 Canadian pesos (to borrow a phrase) it's a real deal.

[macboy]

Yeah, I see your point. 
I also don't want to seem like I'm coming down from Mt Sinai with this thing here either.  I think you can get a UT-61E for only a few bucks more than the normal price of this meter, and I think they finally got around to responsible CAT ratings and what not?  Never mind the greater functionality.  This thing is a nasty cheap meter.  But it's got it's moments, is c/UL/US approved, and at $25 Canadian pesos (to borrow a phrase) it's a real deal.

This one has what I believe to be a perfectly responsible CAT rating: CAT II 1000VDC/750VAC. Now, CAT II is nothing to write home about, but that's the point. It is believable, unlike those "CAT IV 600V" ratings on so many cheapies.  This CAT II meter has fuses on all current ranges, and they appear to be HRC, and are specified to have multi-kA breaking current in the manual. I can see at least a PTC and a MOV  inside, more than what is found those supposedly CAT IV meters. The combination of LEDs and warning beeper is a nice addition that will help prevent you from doing an "oopsie" measurement of mains voltage across the current shunt. This will certainly help to prevent the testing of the quality of those fuses. But in any case they should be good enough for measuring an inherently limited energy CAT II circuit. If you did that oopsie on a CAT IV high energy circuit ... nice to have known you.

[macboy]

Hey, this thing is pretty awesome for a cheapy, and I should know, I've owned an awful lot of cheapies. 
...
Hold is the typical useless type.  It'll even hold a blank screen while autoranging for you!

You are lucky to get a Hold function on a cheapie. I used it when comparing measurements between multiple meters (testing the same cap or resistor).

Input impedance of this model appears to be 11Mohm - manual claims 10Mohm. 

11 MOhm is common on some ranges especially the higher ones, as an extra resistor is added to the bottom of the 10 MOhm divider. If you check on a lower voltage range, you will likely see 10 MOhm (I haven't verified).

Not so good:
The uA range has a 100 ohm shunt so I guess 100mV/mA?

So on the 600.0 uA range, full scale burden voltage is only 60 mV? Not bad at all. Once again we are lucky to get a uA range at all for the price... and it's very accurate.

No mV range.

That's what I thought too. Actually it does have a 600 mV range, it just won't auto-range to it. Press the range button a few times and you will find it.

EUART TX goes into IC2, which appears to be an amplifier for the beeper and LEDs.  No data on it I'm afraid.

I am almost certain that I saw "24C02" with some prefix on that SOIC-8 IC2. That would make it an EEPROM. That's what I had assumed it would be so I didn't pay too much attention. I'll check again later.

[Bud]

Did you take the halo picture in daylight of electric light? You sure it is on the lcd and not on the internal side of acrylic cover?

The first pic was taken in daylight and to see have to manouver the dmm just right to see it in full

Ok i finally could see some tint if i stay by the window and "have my tongue at the right  angle"  ,though seems to be less pronounced then in your photo. Not visible in electric light.

[macboy]

FWIW, there is no issue with the LCD on mine. The contrast is good, but only when looking straight on or lower. If the view angle is from above, the contrast fades significantly.

[Bud]

Same here, with backlight on the view angle from above fades even faster.

[Paul Moir]

Oh I didn't mean to say that this one didn't meet it's CAT rating:  this one seems to meet the claimed CAT II to me, and apparently UL thinks so too.  And I doubt it's phoney given the amount of electrical gear CT brings in from China.  They must be wise to that.  I meant UNI-T might be worth considering they're not being so immoral anymore.  Also the LEDs:  I agree, an ounce of prevention is worth a pound of cure.  Root cause analysis:  why did he blow his arm off? dummy had the leads in the wrong sockets.  Why did he have the leads in the wrong sockets?   Dummy I guess.  Good enough for Fluke!   

10M confirmed on the lower ranges.  That makes sense, thanks!  Much better than the previously reported 1M which must have been an older model?

60mV:  I failed to do the math or even a ballpark estimate.  100mV/mA *sounds* like a lot, doesn't it? 
I'm very glad to have this function.  It's a big deal to me too.

mV Range:  Awesome, I completely missed that.  But I'm only seeing it on AC.  I'll have to play around a bit more.

IC2 - Meant U2, on mine it's the unlabelled chip below J8.  I'm sorta guessing it's a transistor array and that R29-30 are base resistors between it and IC1.  I do want to hunt a little bit more around on this thing.  Oddly the LED on the V/OHM/etc input socket is different from the ones on the current input sockets.  It has a clear lens while the others are red....

Oh, speaking of which, not much to report from the other side of the PCB.  4MHz crystal for the controller and not much else.  I took a photo if anyone cares, but there's not much to see.

[macboy]

My previous post updated including testing big caps (as in sixty thousand microfarad big).

[macboy]

I pulled a 66.6666 MHz oscillator from a junk box just to see if this thing would measure it. "66.68 MHz" on the display.   I was almost amazed. Sure it said 66.68 not 66.67, but to be fair, the oscillator frequency does shift with supply voltage and I was just hitting it with 5-point-something Volts. Then I pulled my old HP pulse generator from under the bench and set it up. The limit seems to be around 73 MHz.

The specifications on the package tell us that this meter will measure frequency up to 100 kHz. We've done nearly 3 orders of magnitude better. For capacitance as well, spec says up to 100 uF, but I measured nearly 60000 uF.

[Haplo]

Just a heads up for anyone else that wanted to buy this. This will be on sale from $29.99 (50% off) from August 14th to August 20th. I was waiting for this to go down and had it price warning turned on it for it and got an email just now.

[Connecteur]

I just bought this unit from Canadian Tire, and I think I know why they are blowing them out so cheap. They are probably getting massive returns of this item.  It doesn't say anywhere that batteries aren't included on the package or in the manual.  This leads the average buyer to conclude that it's probably a defective unit, and should be returned.  After all, it's rare for a DMM to come without a battery installed.

I was almost fooled myself; I decided to test it before I left the store parking lot, and saw that it didn't turn on. I looked in the manual to see if there were any special first-time use instructions regarding batteries, but there were none to be found.  It seemed unlikely that such a product would come without batteries, but I opted to look for a small screwdriver and I unscrewed the battery door. Inside, there were no batteries, so I went back in the store and bought some AAAs, and put them in.  It seemed to work perfectly.  All things being equal, I think this is a fabulous deal at $29.

[retiredcaps]

I just bought this unit from Canadian Tire, and I think I know why they are blowing them out so cheap.

They regularly go on sale for 50% or more.  Even at 50%, they are making money.

All things being equal, I think this is a fabulous deal at $29.

It is a good deal for Canadians because we don't have a lot of brick mortar choice for multimeters.  For many of us, we pass a Canadian Tire store on the way to work, school, errands, etc.  Canadian Tire also has a very generous return policy so if you don't like it or it breaks, we get our money back.

The name brands like Fluke, Agilent, etc all sell for CDN MSRP and with the weak CDN $$$, it is a lot of money for the hobbyist.  The same no name crappy meters that sell for $3 USD in the USA are sold here in Canada for $15 CDN.

[retiredcaps]

It seemed unlikely that such a product would come without batteries,

I can think of a few reasons why batteries are not included.

1) save cost
2) possible regulations prohibit shipping of batteries
3) AAA cells might leak due to cheap brand/poor build quality and/or expire between time of manufacture and sell date
4) prevent people from turning on the multimeter and purposely leaving it on in the store (yes, there are people like that), thus draining the battery and possibly causing it to leak
5) liability - prevents people from "testing" the multimeter by plugging it into a Canadian Tire store outlet while the range select is set to mA or A

[SkyMaster]

It seemed unlikely that such a product would come without batteries,

I can think of a few reasons why batteries are not included.

1) save cost

It has to be to save cost, and make more profit by "forcing" the buyer to buy name brand batteries off the shelf.

Even when on sale at 50%, Canadian Tire is probably still making a profit in the neighborhood of 80% on these products.

Canadian Tire could sell quality DMM and still make a profit, but Canadian Tire decided to sell bottom of the barrel quality DMM in order to make even more profit.


Nothing wrong buying these when someone has only a small budget for a DMM, but these DMM look like extreme low quality even when they are still in their plastic blister.

[saturation]

Those are decent CATII safe meters at the sale price.  The UL marks are easy to confirm.   Note safe does not imply functional, reliable or accurate.

52-0052-2

http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=PICQ.E228905&ccnshorttitle=Measuring,+Testing+and+Signal-generation+Equipment&objid=1075935173&cfgid=1073741824&version=versionless&parent_id=1073991173&sequence=1

FWIW UL is the most expensive of the NRTL labs, less manufacturers use them today, even Fluke just uses CSA.

E.g. costs to certify:

http://www.seldirect.com/ratebudget.html

[Paul Moir]

Canadian Tire could sell quality DMM and still make a profit, but Canadian Tire decided to sell bottom of the barrel quality DMM in order to make even more profit.

You should actually try one before condemning it.  It's a great little meter for the price.  I've seen a lot worse for a lot more money.  You may be right and it's a loss-leader, but that's a common retail practice and nothing to get wound up about.

Thanks for the heads-up, I think I'll get a second one.  Last time all the local stores were sold out, except one where they forgot to hang up the sale price tag.  They had a bunch. 

[SkyMaster]

Canadian Tire could sell quality DMM and still make a profit, but Canadian Tire decided to sell bottom of the barrel quality DMM in order to make even more profit.

You should actually try one before condemning it.  It's a great little meter for the price.  I've seen a lot worse for a lot more money.  You may be right and it's a loss-leader, but that's a common retail practice and nothing to get wound up about.

Thanks for the heads-up, I think I'll get a second one.  Last time all the local stores were sold out, except one where they forgot to hang up the sale price tag.  They had a bunch. 

I am not condemning them. I was actually impressed by the measurement results posted from macboy, a while ago.

I buy from Canadian Tire every week. Once I went to the DMM alley, the DMM were one sale. There was a bunch of them available. They all looked wrong; LCD display crooked in the case window opening, yellow paint incorrectly applied on the selector knob, etc.

I already have 10 DMM (handheld and Bench type), half of them bought used, yet I could not convinced myself to spend $30 (or so) on a 52-0052-2 DMM.

Again; Nothing wrong buying these when someone has only a small budget for a DMM.

[SkyMaster]

Those are decent CATII safe meters at the sale price.  The UL marks are easy to confirm.   Note safe does not imply functional, reliable or accurate.

52-0052-2

http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=PICQ.E228905&ccnshorttitle=Measuring,+Testing+and+Signal-generation+Equipment&objid=1075935173&cfgid=1073741824&version=versionless&parent_id=1073991173&sequence=1

FWIW UL is the most expensive of the NRTL labs, less manufacturers use them today, even Fluke just uses CSA.

E.g. costs to certify:

http://www.seldirect.com/ratebudget.html

Thank you for posting these URL.

I wonder if it is possible to the Chinese manufacturers to get their approval in China from authorized certification labs. These Chinese labs rates would be significally lower.

[Paul Moir]

I think they do have labs all over, but perhaps labour isn't the big cost.   There's companies like Intertek (ETL mark, CSA & UL competitor) that do it apparently cheaper than both and are acreditied in Canada & US.

I'm not particularly price sensitive but for a couple toss around meters for the home workshop and cottage or various other places you say "I wish I had a meter for this...".   

[Kappes Buur]

http://www.canadiantire.ca/en/pdp/tools-hardware/electrical-tools-accessories/electrical-supplies-parts/testers/mastercraft-deluxe-digital-volt-meter-0520055p.0520055.html#.Vc7ZP7R0fGJ

The sale started today. At that price I bought 2.
An interesting feature is, an LED lights up when the leads are either not attached or not inserted all the way.

[retiredcaps]

http://www.canadiantire.ca/en/pdp/tools-hardware/electrical-tools-accessories/electrical-supplies-parts/testers/mastercraft-deluxe-digital-volt-meter-0520055p.0520055.html#.Vc7ZP7R0fGJ

Can you post some teardown pictures of this manual range meter for us please?

[Kappes Buur]

I hope these will do
Click on image for larger size