EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Kiriakos-GR on September 05, 2010, 04:21:47 pm
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Hi
The all idea are " we " the forum members, to create an database of the small sized multimeters ,
that we own , and they do pass the test of " Mains 110/220 over the Ohms range "
All that you have to do , if you are willing to test your meter , are to measure Mains by having the meter at the Ohms range .
Its a bit Risky task , mostly if the cheap meter is that cheap , that it could possibly die on the test.
I will not write , an large BEWARE - WARNING or such notices , its up to you , if you are willing to test it.
Let the meter on an desk or chair alone , and just connect the leads with Mains ( safest way to do it) .
My personal thoughts are , that if any meter that I own has an issue like this , I like to be aware of it, upfront.
And so , I tested all my meters , and they survived .
The test period of 10 seconds its enough ,
In the real world , if you have forget the meter at Ohms range and connect it to measure Mains,
you will find and correct your mistake in the first 5 -10 seconds.
The brand and model of the meter .. the word " passed " or Not !!
and one picture of it at 800x600 , its all that you have to add .
If you find this idea useful , help this database to grow, thanks.
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UNI-T UT 30D = Passed ..
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Don't do this test. Most meters these days will pass, some won't. Some start doing strange things with beepers, displays. Some lock-up. But some have been known to explode. Honestly....I mean if your going to select a meter based on such a test then just buy a meter that auto-sense's voltage present and switches to Voltage. Known as V-check and other buzz words.
However if you do try the test and your meter does blow up remember I sell them.... :o
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:P
:D Every one deserves to have an opinion ...
Even so, I will only say that as long there is no TNT on the resistors and chips , the "explosion" it will not take down your home. ;)
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Low cost fuseable resistors have caused explosions. You can get voltage creep across other track's on the board. Despite what you claim the test still has the potental to be classed as high energy. I've seen the proof, but sure go ahead and blow your meters up guys...like I said replacements can be found here. But it's a pointless test in the first place, as to use a product not as intended is like pushing a car and saying "it goes no faster than walking".
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to be honest it's not a great idea to go telling everyone to connect $5 meters like that, the chances of fire and explosion are not to be underestimated. you only need a piece of plastic in you eye to end up blind
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Just wear some gloves and eye glasses. Mains voltage is wussy voltage!
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well if you have some throw away meters go ahead
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Don't see the point of this test either. Sure, it's a good idea when doing a review, but why take the risk with your own equipment? You've almost nothing to gain, and a DMM to lose. Most good DMMs are probably designed to withstand it, just like they were designed to survive a drop from the bench, but that doesn't mean you should go around dropping all your equipment.
I did this experiment with my fathers analog multimeter when I was a kid. Gave some nice sparks and killed the meter movement. Sorry, no video ;).
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to be honest it's not a great idea to go telling everyone to connect $5 meters like that, the chances of fire and explosion are not to be underestimated. you only need a piece of plastic in you eye to end up blind
Well I was crystal clear about this database - safety test ..
I did not speak about price limit ... but adding the Fluke 87-5 (2010) in the list,
or the Fluke 8010 & 8012 and 8050 that was made at 1977 , and they do pass the test ,
its no useful .
By pretesting your Gear , YOU ARE the one who will fill EXTRA SAFE about it .. and you will not engage in an accident even by mistake ..
So I will suggest politely , " no more nags " ...
If you decide to test your meter , post your findings ..
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If the meter has passed IEC61010 it will (or at least should) pass this test. Any meter that has the CE mark (which it has to have if sold in Europe) will have passed this.
Of course if you do the test and it fails with the CE mark then report it to Trading Standards (UK) as you have been sold a meter that is illegal.
Of course if you really want sparks, super impose a 8kV transient on the mains. When one fails you really get fireworks. (the best on I saw took out the 150A fuse to the lab.)
Neil
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If the meter has passed IEC61010 it will (or at least should) pass this test. Any meter that has the CE mark (which it has to have if sold in Europe) will have passed this.
LOL. People often joke about CE standing for China electronics. The Chinese answer to questions about certification is often 'please send us a copy of the artwork, then we will print it on the label'. I'm sure this is illegal for the importer, but that doesn't mean they don't exist.
I agree with the rest of your post. For proper IEC61010 testing, you should actually impose the transient (I think 8kV is for CAT III 1000V/CAT IV 600V) with the proper (low) output impedance. I'm sure that would make failure much more spectacular.
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If the meter has passed IEC61010 it will (or at least should) pass this test. Any meter that has the CE mark (which it has to have if sold in Europe) will have passed this.
LOL. People often joke about CE standing for China electronics. The Chinese answer to questions about certification is often 'please send us a copy of the artwork, then we will print it on the label'. I'm sure this is illegal for the importer, but that doesn't mean they don't exist.
I agree with the rest of your post. For proper IEC61010 testing, you should actually impose the transient (I think 8kV is for CAT III 1000V/CAT IV 600V) with the proper (low) output impedance. I'm sure that would make failure much more spectacular.
Correct, the actual test for CAT III & CATIV is 8000V transients with a 2 ohm source and the test is repeated 20 times. But most meters are designed to meet the standard, rather than being tested to comply with the standard. There is a very big difference.
Regarding the CE joke, it's not actually a joke it's a fact. Some products have a CE symbol which the chinese say stands for China Export but it very similar to the E.U.'s CE mark, and is very deliberate. Also another issue is that the CE mark and standard now uses a "Self Declaration", so while it's expected that it would have been tested by a indepentant lab, it may not have. If you see UL, TUV or CSA marking's on a product they carry more weight because they are indepentant lab's.
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there was a thing once of the "CE" mark and the "C E" mark, it was a chinese workaround and the modified logo to be spotted only by those who knew the difference in the space between the letters was to say it stood for "chinese export" not much different from "make in UK" and the factory is called UK and so on for any nation of town name, why we sit here and admire how the chinese economy has taken off it should be remembered how they don't give a hang and will do anything for money if they can get away with it
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If you see UL, TUV or CSA marking's on a product they carry more weight because they are indepentant lab's.
The Chinese have no qualms to fake every marking they get their hands on. They give a f*cking fart about them.
The usual excuse is that this is a cultural issue. Chinese claim if you are only willing to pay X amount of money for something and it isn't possible to actually include the testing for that amount then it is your, the buyer's, fault for only paying X. It is not the manufacturer's fault for not telling you and just faking a safety marking. The reality is much simpler: It is not a cultural issue, it is scrupulous greed and giving a f*cking fart if a few Europeans die.
If you want to get an idea about the scale, search for the weekly EU RAPEX (Rapid Alert System for Non-Food Products) reports. Currently there is a wave of products containing illegal chemicals. RAPEX reports often show such waves. Not because there is a certain increase in a particular safety matter, but because national safety agencies currently focusing on those. They don't have the resources to monitor everything all the time. Look through the reports for a wave of unsafe electrical items. If you find it, remember you still only see the tip of the iceberg.
In 2006 an agency tested cheep multimeters, most, if not all of Chinese origin. Not a single one was ok. A good bunch had severe safety issues. The videos of exploding meters you find around the net are often from this study.
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I would second all of that,
When I was receiving sample shirts from china that had material so thin that they were already ripped the ugly truth sunk in. how can a company in china send you a "high quality" sample that is falling apart it has so little material in it ? you are talking about a culture that is used to living poor but always wanting to make it big, those that do then don't give a ratys ass about anyone else as though their owed something, same for any millionair anywhere in the world
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I am just going to assume here that my new Agilent U1252B would complete the task without issue, as there's no way I'm going to try plugging it into the mains. Well unless someone is prepared to give me the £370 for another one ;)
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This is the second page of this thread with out any input of an tested DMM .
1) I feel happy about it : because at list the awareness level of our forum members looks high.
( And so all the efforts of Dave so far , about raising awareness looks to be effective )
2) I feel sad : because blaming China as country its an irrational act .
I do not care about any " panty made in China ", other than the current multimeter 's ( 2007 - 2011 )
Dave had the chance to test some of them , that they had succeed on the test .
Ok the 50$ mark , its not dust and water .. This price range looks to meet all the basic quality standards.
By my personal estimation , there must be no more than 20 untested cheap multimeter 's out there,
so by having or getting awareness about them , it will give us the picture , or the complete current map ,
of the currently marketed DMM 's ..
Something that is missing totally from the EEV blog .. ( not the forum ) its an official database of all the Currently tested DMM , with an picture + descriptions :
Price range : Low Med High
Passed or failed : accuracy - Volts at Ohm test - quality of plastics - display quality.
Yes the EEV-blog videos they do present all those factors , but this EEV DMM database ( or tested multimeter 's library ) its an useful " quick guide" to have ..
For Now , I do not plan to load more work on Dave's solders , but at your own !!
If you have any results of the " MAINS over Ohms " test , add it here ...
OR
Write an review about it ( your DMM ) and post it here ..
(Forum users reviews )
https://www.eevblog.com/forum/index.php?board=9.0 (https://www.eevblog.com/forum/index.php?board=9.0)
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I'm afraid that just because we will happily buy a dodgy meter for £5 is not a good excuse for china to make them. unfortunately we all want to pay less and few of us recognise quality until we have paid over and over again for substandard products. if people just refused to buy the crap then the crap will not be made, I happily pay a few more pounds for a product knowing it will be much better than the cheapest, unfortunately most won't
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we will happily buy a dodgy meter for £5 is not a good excuse for china to make them.
Have you ever evaluate the true cost of the electronic parts used on one £5 retail DMM ?
Its less than half £ , stop the nagging and start build some .. ;D
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panty from China? thin material?
shirts, i once worked for a guy in italy that wanted to import clothing, we got shirts so thin they were ripped, and those were samples
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well it was hard enough getting any samples, most of the time the reply was: sent us yours and we will make a copy of it, then you sent us an order if you like it, china the massive photocopying machine
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china the massive photocopying machine
Well it know that the Chinese cloth fashion , its not special ..
Next time Get Italian ... Go for Armani ;D ;D ;D
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china the massive photocopying machine
Well it know that the Chinese cloth fashion , its not special ..
Next time Get Italian ... Go for Armani ;D ;D ;D
yea: armani - made in china (of course make the A into a and you have another name ?)
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made in china
If this is your major concern , well currently they lead , and we are follow ..
And so, lets get busy with the " Mains over Ohms range " test.
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Correct, the actual test for CAT III & CATIV is 8000V transients with a 2 ohm source and the test is repeated 20 times. But most meters are designed to meet the standard, rather than being tested to comply with the standard. There is a very big difference.
Regarding the CE joke, it's not actually a joke it's a fact. Some products have a CE symbol which the chinese say stands for China Export but it very similar to the E.U.'s CE mark, and is very deliberate. Also another issue is that the CE mark and standard now uses a "Self Declaration", so while it's expected that it would have been tested by a indepentant lab, it may not have. If you see UL, TUV or CSA marking's on a product they carry more weight because they are indepentant lab's.
Yes, manufacturers should perform type testing which is normally destructive: your DVM doesn't need to actually survive an 8kV spike, it just needs to not blow up or electrocute the user when subjected to such abuse.
I'm not sure that using an independent lab is necessary better, in the US I believe that UL overcharge and take advantage of their near monopoly position which just makes it harder for companies to get their produces into the market place. In my view, I see no problem if a European company can prove they've designed their product in accordance the appropriate safety stands and have tested it thoroughly.
Of course no Chinese company ever bothers with all of that hassle and will just sell anything.
Have you ever evaluate the true cost of the electronic parts used on one £5 retail DMM ?
Its less than half £ , stop the nagging and start build some .. ;D
How are you going to mount an IC's die directly on the board so you can cover it in resin?
If you build a DVM to a similar specification yourself, it will cost much more because you'll probably have no choice but to order decent components in small quantities. You could try your luck with ebay but your more expensive meter might end up being as bad or worse than the Chinese one.
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How are you going to mount an IC's die directly on the board so you can cover it in resin?
I will use the same robot that those people use ... in their assembly line..
Now lets go back on topic..
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then it will costs you more than £0.5 to make, back to topic: I'm not risking any of my meters, what about yours ? what have you got and have they passed ?
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back to topic: I'm not risking any of my meters, what about yours ? what have you got and have they passed ?
Yes I have full success :
UNI-T 30D Passed ... no incidents at all ( incidents = flashing display or messages )
Pro's kit 03-9303C Passed ... no incidents at all ( Got an minus indication as response of the connection)
The analog Metrawatt MA 4S ( 1980 ) got tested too , it has inner relay as protection,
it made an click sound and interrupted the connection of leads with the meter .. ;)
Both Fluke 8010 & 8012 passed
Fluke 8050 Passed
The Fluke 87-5 passed ( with some difficulty ) it was asking for more than 220 to be tested,
and I had nothing to give .... ;D
Anything that called as multimeter in my repairs shop , it did pass the test .. and it feels good. ;)
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Yes, manufacturers should perform type testing which is normally destructive: your DVM doesn't need to actually survive an 8kV spike, it just needs to not blow up or electrocute the user when subjected to such abuse.
Is that true of the Ed3 standard?
Also - it is expected that the importer of any product made outside the EU will have the device tested. In the event that it fails in the field they will be the ones held responsible.
Neil
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In all my life ( and I am 41+ ) I have not see any declaration .. as tested by the importer at any product.
Everything looks to sold on " good will " ... and the only safety net its the product warranty.
But what good has the warranty to offer in something that its made to die !!
And what if , in the printed instructions there is an " Warning " ...Beware do not use the meter at Oms range at Mains ...
And so what ? ... does that makes any sense ?
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Additional info for the Pro's kit 03-9303C , That I safe keep the box since 1994 .
( I actually scanned the meter on my EPSON flatbed :) and did an amazing work )
Pictures ..
(My only nag are that the 20M & 200MOhms range are out of calibration,
and I have no info about repairing it )