Chinese Multimeter

[bobcat2000]

First timer here,

This is a great forum to learn electronics.  Nice meeting you guys.

I have a Fluke 73 for like forever.  A friend of mine always bring me small electronic gadgets for me to fix.  I check mostly voltage and continuity.  Nothing fancy.  Sometimes I want to check for mA.  The Fluke 73 can't do it.  I can try to check mA with the 10A plug. But the reading will just jump up and down.  So, I check Amazon to see what meters they sell there.

I come across this AmazonCommerical 90DM160.  This is a CEM DT-916N  for $27.  It comes with everything I need except a bag. (I really want a free bag.) But it only has a 1-year warranty.

https://www.amazon.com/AmazonCommercial-Count-Ranging-Digital-Multimeter/dp/B07VY421KJ/ref=pd_sbs_328_7?_encoding=UTF8&pd_rd_i=B07VY421KJ&pd_rd_r=448f80c7-6068-4757-8e86-2945d573a2ec&pd_rd_w=VMNsM&pd_rd_wg=xysrs&pf_rd_p=7cd8f929-4345-4bf2-a554-7d7588b3dd5f&pf_rd_r=JFAAJ1X2ZB8VG4RB0Z7Y&psc=1&refRID=JFAAJ1X2ZB8VG4RB0Z7Y

I also checking out the Greenlee DM-65 for $50.  (23 clams more)  It is a 2012 model.   It comes with a Limited Lifetime Warranty.  I do want a longer warranty.

https://www.amazon.com/Greenlee-DM-65-CATIV600V-Ranging-Multimeter/dp/B007ORQ7HW/ref=pd_rhf_dp_p_img_4?_encoding=UTF8&psc=1&refRID=XSE38PH2A3BK5R216TXA

Both are made in china.

I don't use the meter everyday but I do want a meter that works when I dig it out from my garage. (like my Fluke).
Would you guy give me some pointer for a cheap meter please?

Muchas gracias!

[shakalnokturn]

You could build a fused current shunt to plug into your Fluke. Works out cheaper and more reliable but if you really need a new cheap multimeter I can understand that.

[bobcat2000]

One time my friend brought me a digital clock that uses a 5V USB cellphone charger.  The display was not working.  I first checked the charger to see if it put out 5V.  It was ok.  I then checked if there was a voltage going in to the display.  There was a voltage.  So, I wanted to check if there was enough power (mA) going to the display.

I don't know how to check this with the Fluke 73.  The Fluke 73 does not have a mA plug.  That is why I want to buy another meter.  Something cheap, reliable, and can last for years from China.  I used to have a meter that was made in Japan but it only last for couple years.

I didn't know how to check the mA with the Fluke.  So, I started by running 1.5V and started to increase the voltage directly to the display until it lighted up.  The display lighted up as I increased the voltage. So, I knew the USB charger was not putting enough power to power the clock.  I ended up replacing the 5V USB charger with a 12V power supply.  The clock worked again.

I don't know what a shunt is.
You saying I can check mA with the 10A plug by putting something in between the thing and the meter?

[tautech]

Bob, recommendations for DMM's are more than there are days of the year. 
If you want something to take the lion's share of the work away from your Fluke and still have a dependable meter get the likes of a Fluke 15B+.
https://www.ebay.com/itm/New-FLUKE-15B-F15B-Digital-Multimeter-Meter-with-LED-Backlight/223660992797?hash=item34133be91d:g:zL8AAOSwPsBa8SF8

[bobcat2000]

Thanks!

The 15B+ is very nice.  It has all the same functions I want from the Amazon 90DM160 and the Greenlee DM-65.

[bobcat2000]

Thanks all for your pointer.

I think I will get the AmazonCommerical 90DM160 for $27 bucks.
This Amazon one is in my budget.  If it stops working in a year, I can just trash it and buy another one.

[bobcat2000]

Both the Amazon 90DM160 and the Fluke 15b+ use a tiny chip.  The Fluke 117 uses a big chip.

Does using a bigger chip make the reading better?  One has a tiny chip with the black thingie glued to the board.  The other has a big chip mounted to the board.

They are all surface mounted.  Assuming they did not put any copy protection to the PC Board.  It seems to me the small chip has more connections than the big chip.  The big chip only has a hand full of pin connected.

Danken!

[bobcat2000]

Wow!  Thanks Blueskull!

I always wonder why they glue the chip on the board in many gadgets.  I always thought they use the glue to cover the marking on the chip.  So, people don't know what chip they use.   If I remove the packaging from the big chip, the chip inside may be just as small as the small chip as well.  So, the Amazon 90DM160 using a small chip may be more efficient than ones that use a big general purpose chip since the small chip has less moving parts.

So, bigger does not mean better.

[Fungus]

If you just want a basic meter that you can't kill, consider the China only Fluke 101

The 101 doesn't do current and the OP wants mA.

The Greenlee looks good to me for $49.

Both are made in china.

So?

[Old Printer]

The last thing i would be worried about is warranties on a $27 meter. Not likely to use it anyway, most of this stuff is either no good out of the box in which case you return it, or it works for years. My experience anyway.

[bobcat2000]

I decided to get the Greenlee DM-65.  Not the Amazon meter.  The only reason to pick the Greenlee is the "Lifetime Limited Warranty".  The DM-65 is made by a company called All Sun.  The date on the packaging is dated 2011.

I play with the DM-65 for a while.  It sucks compared to my 20-yr old Fluke 73.  The plastic smells bad and the screen is terrible.  The letters are a little bit bigger but I have to look it straight otherwise the letters are all washed out.  The backlight does not help at all.  The letters from the Fluke are dark and clean from any angle.  The leads are just bad.

I thought the meter was not working.  It turned out the leads had so much coating. It did not make any good connection.  I cleaned the leads with alcohol.   I could not clean the plugs.  There was a plastic bumper inside the plug.  It is better but the connection is still not good.

Otherwise, I can check mA now.  Yeeeeaaaa!

I was wondering why my La Crosse BC-900 charger took so long to charge my batteries.  The screen said 200mA.  It turned out it was putting out only 20mA.

[CDaniel]

If you are serious in what you are doing , a cheap chinese meter is not what you need .
Unfortunatly many people want cheap stuff 

[bobcat2000]

If you are serious in what you are doing , a cheap chinese meter is not what you need .
Unfortunatly many people want cheap stuff 

Cheap is good.  However, I prefer free better.

More pictures
Radio Shack Micronta 22-212 UL Listed
Meguro MDM-1180 No rating at all
Fluke 73 UL Listed
Greenlee DM-65 "Confirms" to UL

[retiredcaps]

The only reason to pick the Greenlee is the "Lifetime Limited Warranty".

I have asked this question before on the forum wrt to other Greenlee meters (specifically rebadged Brymen)  and never got an answer where it states publicly on Greenlee's website in terms of how many years lifetime is defined as.

For example, some modern Fluke meters that have "lifetime warranty" have clearly defined terms and conditions in the user manual that clearly state the number of years the meter is under warranty DESPITE the wording lifetime.

[bobcat2000]

This is what Greenlee printed in the user guide.

Lifetime means "useful life".  Just like the transmission oil in your car.  Many cars are now said to have "Lifetime" transmission oil.  So, if the oil is good for 100 miles, "Lifetime" means 100 miles.  Lifetime for Fluke is 10 years of "useful life".  Fluke is nice enough to tell you their definition.

I understand what you say.  All these warranty they want me to believe actually means nothing.  Whether it is 1 year from the Amazon meter, 3 years from Amprobe, or whatever they printed in the user guide, there is no law to make them give me a new meter.

This would be nice if they could replace the meter since they put a huge label saying "Lifetime Warranty" on the box.  It is really up to them to make their customers happy.  So, people will not bad mouth their company.

Lifetime Limited Warranty
Greenlee Textron Inc. warrants to the original purchaser of these goods for use that these products will be free from
defects in workmanship and material for their useful life, excepting normal wear and abuse. This warranty is subject
to the same terms and conditions contained in Greenlee Textron Inc.’s standard one-year limited warranty.
For all Test Instrument repairs, contact Customer Service at 800-435-0786 and request a Return Authorization.
For items not covered under warranty (such as items dropped, abused, etc.), a repair cost quote is available
upon request.
Note: Prior to returning any test instrument, please check replaceable batteries or make sure the battery is at
full charge.

[J-R]

What is the internal resistance of the DM-65 in the mA mode?  It's possible it will have an impact on the charging circuit.

The Fluke 73 can measure down to 10mA in the 10A mode.  The internal resistance in this mode will be very low.  200mA should be easy to resolve in this case and shouldn't impact the charging circuit.  The DM-65 might be similar in the 10A mode so could be worth giving a try as well.


I'd suggest picking up another meter to help with measurement verification.  Older used Greenlee, Fluke, and Amprobe meters are worth considering.  Maybe a new Brymen BM231.

[bobcat2000]

What is the internal resistance of the DM-65 in the mA mode?  It's possible it will have an impact on the charging circuit.

The Fluke 73 can measure down to 10mA in the 10A mode.  The internal resistance in this mode will be very low.  200mA should be easy to resolve in this case and shouldn't impact the charging circuit.  The DM-65 might be similar in the 10A mode so could be worth giving a try as well.


I'd suggest picking up another meter to help with measurement verification.  Older used Greenlee, Fluke, and Amprobe meters are worth considering.  Maybe a new Brymen BM231.

How do I check the internal resistance?  Turn the dial to mA and check the resistance with another meter?  I don't know how to check mA with the Fluke 73.  The reading just jump up and down all over the places.  Same with the DM-65.  If I try to check mA with the 10A plug, the reading will jump up and down.

I find a picture of a All Sun meter that looks exactly like the DM-65 from the All Sun site.

[J-R]

Yes, use another meter to measure it in each mode.  As an exercise it would be worth checking mA, 10A and also DC V.  This will tell you what the meter will do to the circuit/device you connect it to.  In general you could expect to see below 1 Ohm for 10A, above 1 Ohm for mA and about 10M Ohms for DC V.


I have a similar charger and had no issue using various DMMs in the 10A mode to detect the 200mA (0.20A) charge current going to the battery.

Just to clarify, on the DM-65 when using the 10A plug you are using the A switch position and have it set to DC A not AC A?  And the DMM is in series with the battery and charger, not in parallel?

[bobcat2000]

Thanks JR!

The DM-65 can also check micro amp.

micro Amp is 51.7 
mA is 2.2 
10A plug is 0.2 
DC V is 7.75 M\$\Omega\$

I also have a EBL-999 10-bay charger.  The label says 270mA.  The meter shows me ~200mA.  So, I guess this AA charger is ok.

The BC-900 is switchable from 200mA to 1A.  The default is 200mA.  The meter shows me only ~20mA.  This is possible that the BC-900 starts at 20mA for couple hours before it cranks up the power.  Just maybe.  Another possibility is that I use too many wires to hook up all the stuffs in series with too much resistance, the BC-900 may think the battery is full.

And yes, all connection and dial position are correct.

[bobcat2000]

More pictures for this Chinese meter.

The green rubber boot is heavy.  The meter itself is quite light.

The inside looks good to me.  Compared to all the gadgets my buddy asked me to fix, this meter looks state of the art.
 

[bobcat2000]

I have a similar charger and had no issue using various DMMs in the 10A mode to detect the 200mA (0.20A) charge current going to the battery.

Ah!  I have 2 battery chargers that put out 500mA.  I test the current with the 10A plug from both meters.  Both meters can display ~500mA from these 2 chargers ok.  So, I guess 200mA is too weak for the 10A plug to check.

[J-R]

I have a similar charger and had no issue using various DMMs in the 10A mode to detect the 200mA (0.20A) charge current going to the battery.

Ah!  I have 2 battery chargers that put out 500mA.  I test the current with the 10A plug from both meters.  Both meters can display ~500mA from these 2 chargers ok.  So, I guess 200mA is too weak for the 10A plug to check.

Both meters should have the resolution and accuracy to display 0.20A, but if that other charger is only providing 0.02A, then it could be tricky to get a meaningful reading in that range.

If you have a DC power supply with current limiting you could run some tests to get a better idea of what each meter can actually do.  As an example you could set the DM-65 to the mA range, the Fluke to the 10A range and then run the power supply current slowly up from zero with everything in series.  Between 0 and 500mA seems reasonable.

[rsjsouza]

Thanks for sharing the photographs of this DMM. I was always curious to see how well built this equipment is.

[Fungus]

The inside looks good to me.  Compared to all the gadgets my buddy asked me to fix, this meter looks state of the art.

No surprise. Greenlee seem to know how to choose a meter for rebranding.

[Electro Detective]

Brand and cost aside, the insides of most of these moderno meters is getting way too small for comfort 

With a combo of aging, temperature extremes and -guaranteed to happen- drops on concrete or tiles, causing nano cracks on the brittle lead free bs soldering,

they will become unreliable, intermittent and pretty much unfixable. 
 
I've seen it already, a 'brand name withheld' meter, new in the box, with half the functions DOA or way out of spec.
The replacement sent was spot on perfect, and highly possible from the same batch run.

Even with the working replacement as a reference, it's too much of an unpaid challenge or pride bs to fix the knackered one, and then stuff about calibrating it,
assuming one even gets that far without schematics, microscope, and patience 

The exiled de-crustified AVOmeter has been seeing some use lately,
seen in a window refection displaying the vintage Finger at the modern smart meters when I'm not looking

I don't know how many owners had it before me, nor how it survived years of collegetard abuse before them,
but it's in perfect spec decades later on all the ranges, including the 3kv AC and DC hookup