MJLorton Solar Power and Electronic Measurement Equipment Forum
Youtube Video Episodes => YouTube Video Episodes => Topic started by: kodai on September 28, 2012, 10:30:20 PM
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Great video, Martin. I'm really looking forward to the second part and seeing the overall build quality on a teardown. I'm rather curious if the UltraDMM app will work with this unit. Think you might be able to give it a whirl before you do the review to see if it works?
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I'm rather curious if the UltraDMM app will work with this unit.
Doubtful, I'm 99.5% certain it's not been ported to any 50k count meters. But if you or Martin want to dig up the datasheet for the chip it uses, I'm pretty sure he'll get it running.
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Great video, Martin. I'm really looking forward to the second part and seeing the overall build quality on a teardown. I'm rather curious if the UltraDMM app will work with this unit. Think you might be able to give it a whirl before you do the review to see if it works?
Thanks for the feedback...ok...let me look into UltraDMM and give it a bash as I've not used it before.
Cheers,
Martin.
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Ok...part 2 of the MS8218 review is uploading as I type this...here are some pictures inside it....
Part 2 of the review here: http://www.youtube.com/watch?v=SrdD18ArYfQ
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Calibration probably isn't done via the IR port, but via menus. I imagine it's a sequence for adjusting the offset of each mode and range one at a time, initiated by that button.
The soldering on that IR LED is pretty nasty, a little heatshrink wouldn't exactly break the bank.. Not overly impressed there. There should be another chip under the LCD. Any chance of taking that off and checking the markings on both chips?
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This just another 60$ multimeter.
Nothing of the internals can justify the retail price of it.
Someone commented on the video, that is good just for electronics,
and I will say that electronics haves fast pulses, how this one will do the math? by drinking Red-bull ?
Martin the 630mA Fuse looks clearly to write on it 250V, they cheating even at the fuses..
Take a picture of the metal ring and post it.
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kiri, this isn't a weak "$60" DMM.
they placed the wrong fuses in it it's supposed to be a 6.3x32
The accuracy itself easily pays for the 150$ mark
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kiri, they placed the wrong fuses in it it's supposed to be a 6.3x32
Are you get payed by Mastech ?
I know that I sound harsh but in this subjects there is no room for jokes or excuses.
If another truly serious company had made an such a mistake, it would be at 9:00 o'clock TV news.
My personal Blog are watched by the Greek federation of unions of electricians contractors,
such news they do interest them allot.
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I'm not a Fluke fanboy, but I will point out the following:
1) Amazon.com has the Fluke 287 for $418.14 (round up to $420). The lowest price MS8218 is $180 on ebay. So the Fluke 287 is $240 more money.
2) With a Fluke 287, purchased from an authorized dealer, you get a "lifetime" warranty (minimum of 10 years from date of purchase).
http://www.fluke.com/fluke/usen/service/warranties/default.htm
3) Now if I were a Fluke salesperson, I would argue that $240 buys you
i) 10 year warranty (or $24/year, or 6.6 cents/day)
ii) what warranty do you have with an ebay MS8218 seller that may or may not be in business 10 years from now
4) If your multimeter/job requires annual calibration/traceability, then the initial capital cost of the multimeter is less dramatic when considering the total cost of ownership over 10 years. For example,
10 year ownership x $100 (annual calibration) = $1000
Fluke 287 $420 + $1000 calibration = $1420
Sinometer MS8218 $180 + $1000 calibration = $1180
5) The resale value is quite high for an used Fluke 287 (around the $200 USD range currently on ebay). What is the resale value of a MS8218 after 10 years?
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Nice demonstration of reference voltage drift with temperature. Difficult to fix without having either a ovenised reference or selecting them like Fluke does. You can see the drift is positive on the Mastech ( decreases with temperature) and slightly negative but close to zero with the Fluke.
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ii) what warranty do you have with an ebay MS8218 seller that may or may not be in business 10 years from now
Oh my dear friend, this text bring me tears due extreme laugh's ;D ;D ;D
Lets turn this conversation in to an educational one, I did one weird thing today,
a tear down of BUSS and SIBA 1000V HRC fuses, and it is sticky topics at my forum.
Have a look, they are very interesting pictures in them.
http://www.ittsb.eu/forum/index.php?board=16.0 (http://www.ittsb.eu/forum/index.php?board=16.0)
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Kiriakos, where are the pictures?
Fuses are a deceptively simple item, but the detail is in how they handle a small overload and a massive one.
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If you get in those two topics you will see the pictures.
If you can not see the pictures as Guest (visitor), send one PM so to check that out and fix it.
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Tried again and they showed up.
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Lets turn this conversation in to an educational one, I did one weird thing today,
a tear down of BUSS and SIBA 1000V HRC fuses, and it is sticky topics at my forum.
Inquiring minds want to know if $2.22 USD + free shipping for 3 (three) fuses are of the same quality.
http://www.ebay.ca/itm/360490914215
500V 10A
The "intended" use, at least for me, is low power DC circuits (< 12V DC). I would put one in a "current measurement only" multimeter and if it blew, no big deal.
PS. Those a great photos and thanks for the teardown.
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In these temperature related stress test the result is always determined by the method of the providing the voltage reference. Does it have software compensation or the cheap trick of using two resistors with inverse temperature coefficients so as they drift they do so in opposite directions.
The cheap chinese meters seem it omit the external voltage reference either from the design or (as is the case with the Unit-t UT61E) just off the pcb even when the footprint is already there.
May be after your initial tests of the UT61E you could mount an LT1790 in U4 and redo the test. There doesn't seem to be that much wrong with the meters design but price constraints mean that if you want accuracy and input protection you expect from the western instruments you'll have to add the parts yourself.
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At 12V almost any fuse will do, not enough arc energy to worry about. The issues come with voltages able to put a lot of energy into the arc. Direct across mains, where the voltage is enough to sustain the arc, and the instantaneous current is able to go to the hundreds of amps to power it during the arc breaking interval. There you need the ceramic body able to contain the pressure, and the fine silica sand to absorb the arc energy and quench the arc by splitting it up.
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In these temperature related stress test the result is always determined by the method of the providing the voltage reference. Does it have software compensation or the cheap trick of using two resistors with inverse temperature coefficients so as they drift they do so in opposite directions.
The cheap chinese meters seem it omit the external voltage reference either from the design or (as is the case with the Unit-t UT61E) just off the pcb even when the footprint is already there.
May be after your initial tests of the UT61E you could mount an LT1790 in U4 and redo the test. There doesn't seem to been that much wrong with the meters designs but price constraints mean that if you want accuracy and input protection you expect from the western instruments you'll have to add the parts yourself.
Interesting, I will try to remember to keep an eye open for that when I have the UT61E in my hands.
Thanks for the post.
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At 12V almost any fuse will do, not enough arc energy to worry about. The issues come with voltages able to put a lot of energy into the arc. Direct across mains, where the voltage is enough to sustain the arc, and the instantaneous current is able to go to the hundreds of amps to power it during the arc breaking interval. There you need the ceramic body able to contain the pressure, and the fine silica sand to absorb the arc energy and quench the arc by splitting it up.
Thanks SeanB....I'm certainly a little wiser after reading your post.
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Great video! I was quite interested in this one, but the no temp, plastic locking nuts and the inside board just put me off. :-)
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Lets turn this conversation in to an educational one, I did one weird thing today,
a tear down of BUSS and SIBA 1000V HRC fuses, and it is sticky topics at my forum.
Inquiring minds want to know if $2.22 USD + free shipping for 3 (three) fuses are of the same quality.
http://www.ebay.ca/itm/360490914215
500V 10A
The "intended" use, at least for me, is low power DC circuits (< 12V DC). I would put one in a "current measurement only" multimeter and if it blew, no big deal.
PS. Those a great photos and thanks for the teardown.
Thanks mate,
those are HRC fuses for electrical motors, which are very slow in comparison with the "super fast ones".
I have many of those.
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kiri, they placed the wrong fuses in it it's supposed to be a 6.3x32
Are you get payed by Mastech ?
I know that I sound harsh but in this subjects there is no room for jokes or excuses.
If another truly serious company had made an such a mistake, it would be at 9:00 o'clock TV news.
My personal Blog are watched by the Greek federation of unions of electricians contractors,
such news they do interest them allot.
What's wrong with that? Why do you bash about a meter that works properly unlike the similarly priced UT71E?
Try getting a new fluke for 150$ and report back, they won't even have 0.03% accuracy.
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kiri, they placed the wrong fuses in it it's supposed to be a 6.3x32
Are you get payed by Mastech ?
I know that I sound harsh but in this subjects there is no room for jokes or excuses.
If another truly serious company had made an such a mistake, it would be at 9:00 o'clock TV news.
My personal Blog are watched by the Greek federation of unions of electricians contractors,
such news they do interest them allot.
What's wrong with that? Why do you bash about a meter that works properly unlike the similarly priced UT71E?
Try getting a new fluke for 150$ and report back, they won't even have 0.03% accuracy.
High price point / Fuse issue / slow sampling for such high counts / internal construction / all of those details came to light due this video review.
Bashing ? SAFETY FIRST !! all the other issues haves a much lesser value.
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Safety first? You've gotta be kidding me. Replace the damn fuses are you are GOOD TO GO. Understand? I said it a couple of times. REPLACE THE DAMN FUSES.
And once again, nobody pays me to make biased comments. I only make unbiased comments.
A fluke's only good for safety and that thinking of mine has gone to Agilent. well then what fluke do we have at 150 bucks (My currency!)? A fluke 115! And that's a whole 100 bucks more!
Bloody hell that thing doesn't even have a current range
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Read and learn .... Except if you have credentials to prove that you are some sort of an expert.
The protection should not be subject only to fuse rating but also to PCB track layout and other factors. The conformity should not be only to fuse rating. The conformity should be checked by the multifunction tests of IEC61010-1 2nd Edition Clause 16.2 as followings.
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Multifunction meters and similar equipment shall not cause a HAZARD in any possible combination of RATED input voltages, and settings of function and range controls. Possible HAZARDS include electric shock, fire, arcing and explosion.
Conformity is checked by the following test.
The maximum RATED voltage specified for any function is applied to each pair of TERMINALS in turn, in every combination of function and range controls. The test source connected to the equipment measuring TERMINALS during this test is limited to 3,6 kVA for measurement category I or measurement category II. For measurement category III or measurement category IV, the test circuit has to be capable of delivering 30 kVA.
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For those interested in this multimeter, it is also being sold as the Protek 6500.
Right now on ebay, there are a couple of interesting auctions for one that works and one that needs repairs (see pictures of obviously leaked batteries).
This could be a good deal for those who want this multimeter at a reduced price. Obviously I can't vouch for the sellers or the condition of the multimeters so caveat emptor.
If someone buys the "parts" Protek and manages to fix it, please post how you did it with teardown pictures.
PS. I have no interest in this meter at the current ebay prices. If I got a broken one for $10, then I might buy one.
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Just for the record, since I won this multimeter off Martin a while back it has been pretty good for my electronics use. It is actually quite nice to use, and the construction quality is certainly adequate. I probably wouldn't trust it for CATIII, but I'm not going to use it for that anyway.
What I do find peculiar is the surface mount capacitors inside. They can be seen at the top in Martin's photo; http://mjlorton.com/forum/index.php?action=dlattach;topic=108.0;attach=313;image
Some of them are stacked on top of each other, and some are seriesed and paralleled. Are they all like this?
I'm also curious to know about the crusty components, including the strange looking current shunt. Are they all weird? Or is it just this one? Accuracy on the 10A range seems reasonable.
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Some of them are stacked on top of each other, and some are seriesed and paralleled. Are they all like this?
C4 doesn't inspire a lot of confidence that the multimeter will survive a drop because it doesn't look like there is a pad on the "triangle" part?
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Nah, they've just soldered two in series and soldered them in parallel with another two parallel caps.
TBH it does look reasonably sturdy though.
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Nah, they've just soldered two in series and soldered them in parallel with another two parallel caps.
TBH it does look reasonably sturdy though.
Obviously, you have the unit in front of you so you are in the best position to tell. I can only judge from the photos.
If the seller for the "parts" MS8218 starts a new auction at 99 cents, then I might be interested ... ;D
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Well someone bought the Protek 6500 for $40.
http://www.ebay.com/itm/261213171798
If someone on this forum bought it due to my heads up, you are welcome! :)
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For those interested in the Mastech MS8218, it is sold under different names and may be cheaper.
Today, I was looking on Amazon and found
http://www.amazon.com/Sinometer-MS8218-000-count-Multimeter-Interface/dp/B002D3G1WS/
$99.95 + free shipping. Don't forget to use Martin's affiliate Amazon link to support him if you are interested in the above for $100.
PS. I have no financial affiliation with Martin or Amazon. I'm just trying to point out a potentially good deal for those interested in the MS8218.