Canadian Tire Mastercraft DMM New and old revision teardown

[saturation]

Welcome.  Yes, effectively all safety organizations have branches in China, given its manufacturing prowess and labor costs.  Any of the safety mark will do as they differ only in cost to the manufacturer, the test is standardized by the IEC.  If any organization fails to live up the standard, they will lose accreditation, testing is their business they have incentive not to be corrupt. 

UL remains more expensive and stricter,  UL may test to UL standards which were/are often stricter than IEC, which is good to see from a safety perspective. 

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.

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...".   

[Len]

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 couldn't resist, I picked one up. For $30 I'm quite pleased with it, except for the probes.

The probes are made of the crappy plastic they use for cheap toys, including sprue marks. They have a UL mark, but there's also a double-insulated symbol (square-in-a-square). Does that even make sense? I don't see how they can be double insulated, because obviously the probe tips are exposed.

[retiredcaps]

I hope these will do

Thanks for posting the pictures.  It is appreciated.

Compared to the auto ranging meter, the manual one sure uses a lot more components.  For example, there are electrolytic caps on the manual and none on the auto.  In addition, the manual meter has a PTC, but no MOV that I can see.

[ralphd]

I have the old version of this meter, which was reading voltages 0.6% to 0.7% high.  I figured out VR1 is the voltage trim pot and have it adjusted to within 0.1% now.
http://nerdralph.blogspot.ca/2015/08/calibrating-cheap-crappy-tire-multimeter.html

My biggest beef about the meter is the 1MOhm input resistance.  If they put the new one on their 60% off sales this fall I think I'll go for it.

[macboy]

I have the old version of this meter, which was reading voltages 0.6% to 0.7% high.  I figured out VR1 is the voltage trim pot and have it adjusted to within 0.1% now.
http://nerdralph.blogspot.ca/2015/08/calibrating-cheap-crappy-tire-multimeter.html

My biggest beef about the meter is the 1MOhm input resistance.  If they put the new one on their 60% off sales this fall I think I'll go for it.

The new one has 10 MOhm input at 60 V and higher ranges and 11 MOhm at 6 V and lower (both AC and DC). This is as measured, not from the spec sheet.

[ralphd]

The new one has 10 MOhm input at 60 V and higher ranges and 11 MOhm at 6 V and lower (both AC and DC). This is as measured, not from the spec sheet.

Have you noticed where the new one switches from 3 digits after the decimal place to two?  On the old one it is around 4V.  So I can measure a 3.3V source down to 1mV resolution, but I only get 10mV resolution at 5V.

[ralphd]

The new version looks like the Colluck HH0308C, rated 0.3% accuracy.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAM/6000_Count_Digital_Multimeter.html

And if that's right, the answer to my last question about the mV range is 6V.

[ralphd]

The new version looks like the Colluck HH0308C, rated 0.3% accuracy.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAM/6000_Count_Digital_Multimeter.html

It also looks like the HH2205D, 0.8% and 1mV resolution only up to 4V.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAf/Trms_Digital_Multimeter.html

[macboy]

The new version looks like the Colluck HH0308C, rated 0.3% accuracy.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAM/6000_Count_Digital_Multimeter.html

It also looks like the HH2205D, 0.8% and 1mV resolution only up to 4V.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAf/Trms_Digital_Multimeter.html

Yes, it looks similar to both but it is definitely 6000 count (see earlier posts in this thread) despite the specs which imply 4000 count as the old version had. To be really pedantic, it is 6200 count, so this means that you can measure up to 6.199 VDC with millivolt resolution. The accuracy (on mine) is much better than 0.3%, again see earlier posts.  Contrary to the Colluck specs, I have measured frequencies over 70 MHz (spec say 600 kHz) and capactiance over 60000 uF (specs say 100 uF).

[ralphd]

The new version looks like the Colluck HH0308C, rated 0.3% accuracy.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAM/6000_Count_Digital_Multimeter.html

It also looks like the HH2205D, 0.8% and 1mV resolution only up to 4V.
http://www.colluck.com.hk/diyhp/9359/enus/c-25520/p-AAASX6AAgAAB4SWAAf/Trms_Digital_Multimeter.html

Yes, it looks similar to both but it is definitely 6000 count (see earlier posts in this thread) despite the specs which imply 4000 count as the old version had. To be really pedantic, it is 6200 count, so this means that you can measure up to 6.199 VDC with millivolt resolution. The accuracy (on mine) is much better than 0.3%, again see earlier posts.  Contrary to the Colluck specs, I have measured frequencies over 70 MHz (spec say 600 kHz) and capactiance over 60000 uF (specs say 100 uF).

Thanks for clarifying.  Somehow I missed you April 17th post when I was reading through the thread.
Will definitely watch for the next time it goes on sale...

[ralphd]

Found it on 50% off sale for $30, so I bought the last one on the shelf at my local CT.
Some initial measurements with some TL431s suggest it is reading about 0.1 - 0.2% high for voltage.  Once I dig out my ref5050s I'll have a better handle on the accuracy.
I also confirmed (no surprise) that it is a 6000 count meter.  It's nice having 1mV precision when checking regulated 5V supplies.  I'll also appreciate the 10M input impedance.

Considering the current USD/CAD of 1.34, after 15% HST and conversion to USD, it's just $25.75. 

I don't know if anyone already mentioned it, but shorting the leads in temp mode seems to give an on-board temperature reading (instead of attaching a temperature probe, which I don't have).
The manual doesn't say what the probe is, but I have some 10K NTCs around somewhere I may test it with...

[ralphd]

Found it on 50% off sale for $30, so I bought the last one on the shelf at my local CT.
Some initial measurements with some TL431s suggest it is reading about 0.1 - 0.2% high for voltage.  Once I dig out my ref5050s I'll have a better handle on the accuracy.
I also confirmed (no surprise) that it is a 6000 count meter.  It's nice having 1mV precision when checking regulated 5V supplies.  I'll also appreciate the 10M input impedance.

Considering the current USD/CAD of 1.34, after 15% HST and conversion to USD, it's just $25.75. 

I don't know if anyone already mentioned it, but shorting the leads in temp mode seems to give an on-board temperature reading (instead of attaching a temperature probe, which I don't have).
The manual doesn't say what the probe is, but I have some 10K NTCs around somewhere I may test it with...

I just checked the diode Vf mode, and it seems to use a higher current than the old one.  Testing a 268 Ohm resistor showed a voltage of .491V, indicating a test current of 1.8mA.  The old meter used a test current in the 400-600uA range.

[macboy]

Found it on 50% off sale for $30, so I bought the last one on the shelf at my local CT.
Some initial measurements with some TL431s suggest it is reading about 0.1 - 0.2% high for voltage.  Once I dig out my ref5050s I'll have a better handle on the accuracy.
I also confirmed (no surprise) that it is a 6000 count meter.  It's nice having 1mV precision when checking regulated 5V supplies.  I'll also appreciate the 10M input impedance.

Considering the current USD/CAD of 1.34, after 15% HST and conversion to USD, it's just $25.75. 

I don't know if anyone already mentioned it, but shorting the leads in temp mode seems to give an on-board temperature reading (instead of attaching a temperature probe, which I don't have).
The manual doesn't say what the probe is, but I have some 10K NTCs around somewhere I may test it with...
[/quwill
Ha-ha, this meter is far more accurate than any TL431. You'll need a much better Vref to test accuracy. I compared against a trio of Keithley 2001 7.5 digit meters that agree within 3ppm of each other.

The temperature probe is a standard k type thermocouple. Presenting a short in lieu of the thermocouple will simulate a thermocouple that is at the same temperature as the reference junction, whether measured or just a fixed value. This is true of any device using a connected thermocouple.

[ralphd]

Some initial measurements with some TL431s suggest it is reading about 0.1 - 0.2% high for voltage.it with...

Ha-ha, this meter is far more accurate than any TL431. You'll need a much better Vref to test accuracy. I compared against a trio of Keithley 2001 7.5 digit meters that agree within 3ppm of each other.

Note I said some tl431s, not just one.  I have 100 0.3% rated TL431s, and have sampled over a dozen of them.  At 25C and 10mA current, the voltages vary by +- 0.22%.  Therefore those samples could be another 0.08% out and still be within the 0.3% spec.  Taking the average of the min and max voltage gives me a reference accurate to +- 0.08%.  Obviously not as good as the +- 0.5% REF5050, but pretty good for parts that cost <2c ea.

[ralphd]

Looks like I fried one of my REF5050s with a solder bridge between pins 1 & 2.     The datasheet doesn't say what happens when you connect the DNC (do not connect) pins, but clearly it's bad.  After removing the solder bridge and connecting 12V to Vin, I get ~4.24V at Vout. :-(

I also did the exact calculation against my tl431 measurements.  They suggest the meter is reading at least 0.02% high, and no more than 0.18% high.

[ralphd]

Anyway, I've ran the meter against Fluke 87-V on DC volts and uA/mA. This Mastercraft multimeter agreed with 87-V  well, especially on DC volts. Pictures are attached below for measuring 1V DC and 1mA DC.

Your 1.002V measurement puts it close to, but still within Colluck's 0.3% spec for the meter.  Macboy seems to have been a bit more lucky with the one he got.  I don't have a reference as good as either of you, but from the measurements I've made mine seems to be reading somewhere around 0.1% high.

[ralphd]

I'm not getting good measurements for low-value capacitors.  A couple of (I think) 22pf caps were reading between .120 and .135 nF.
No problems reading a 100nF and 220nF cap though.

[ralphd]

Just tested a batch of 10 0.1% 250 Ohm 1/4W resistors (5 band, purple tolerance code).
6 of them measured 250.5 Ohm, 3 measured 250.4, and 1 measured 250.6.  So for resistance, the meter seems a little high, but still within 0.2%.

[gardner]

I know I'm dredging up a very old thread here.  But it's interesting.  I bought one of these for the cottage and when I compared it to my Keithley 195A I was amazed at how accurate it was.  On sale for CAN $30 it is a really decent deal.

They are on sale again this week -- through 25-Feb-2016.

When I bought mine I also bought the K-type thermocouple that they sell for it.  The lead spacing on the adapter didn't fit the spacing on the meter so I returned it.  I expect it was meant for the old-style meter or something.

[macboy]

I know I'm dredging up a very old thread here.  But it's interesting.  I bought one of these for the cottage and when I compared it to my Keithley 195A I was amazed at how accurate it was.  On sale for CAN $30 it is a really decent deal.

They are on sale again this week -- through 25-Feb-2016.

When I bought mine I also bought the K-type thermocouple that they sell for it.  The lead spacing on the adapter didn't fit the spacing on the meter so I returned it.  I expect it was meant for the old-style meter or something.

I suspect you were expecting to use the V jack but in fact, temperature measurements use the mA jack. So the oddball wide spacing of the adapter is correct, and it fits between the two middle/bottom jacks.

[Bud]

I am still happy with mine. Could well be something EEVBlog may sell as an entry level meter.

[macboy]

I am still happy with mine. Could well be something EEVBlog may sell as an entry level meter.

I use mine on occasion, often for a secondary measurement in conjunction with a "better" meter.
They are a fantastic value at $30 especially with the CDN$ so low right now.

[l0rd_hex]

Anyone have issues with the temperature probe? Mine just cycles from 14C down to -105C and back to 14C again... I'm using a "CCL131200918" (a $25 special!).

[jesuscf]

Thank you very much for the tip!  I just picked one up from Canadian Tire for the advertised sale price.  I also had $12.05 in Canadian Tire money (mostly 0.05$ bills!) so after taxes and the recycling fee I ended up paying only CAN $22.09.  As many had said already, the Mastercraft 052-0052-2 is quite a nice multimeter from the measurements point of view.  The case quality and finish not so much...

By the way, the k-type thermocouple probe that came with the Brymen BM869s does not fit the Mastercraft inputs.  Time to make a probe with some k-type thermocuple wire and a couple of banana plugs!

I know I'm dredging up a very old thread here.  But it's interesting.  I bought one of these for the cottage and when I compared it to my Keithley 195A I was amazed at how accurate it was.  On sale for CAN $30 it is a really decent deal.

They are on sale again this week -- through 25-Feb-2016.

When I bought mine I also bought the K-type thermocouple that they sell for it.  The lead spacing on the adapter didn't fit the spacing on the meter so I returned it.  I expect it was meant for the old-style meter or something.

[jesuscf]

I just made a simple temperature probe with about five feet of k-type thermocouple wire and two banana plugs and connected it to the Mastercraft 052-0052-2.  I measured several temperatures both with the Mastercraft and the BM869s as shown in the attached pictures .  The measurements are very similar!  Assuming the BM869s is 100% correct, the Mastercraft is well withing the "+/- (3C+ 3 dgts)" stated in the manual. Not bad at all for such an inexpensive multimeter!

l0rd_hex, are you connecting the probe between the TEMP and COM terminals?

Anyone have issues with the temperature probe? Mine just cycles from 14C down to -105C and back to 14C again... I'm using a "CCL131200918" (a $25 special!).