Author Topic: Multimeters that do not appear to meet their safety specs. (updated frequently)  (Read 145899 times)

0 Members and 2 Guests are viewing this topic.

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
Revised: September 27 2013  18h10 UT

It is my intention here to start listing multimeters that appear to have designs or implementations that do match the intent of their rated CAT levels.

The intent of this thread is to provide at least a partial list of multimeters that are to be assessed on their physical and feature merits rather than to rely on their stated CAT ratings for assumption of safety. I will update this post each time I see a new post with a new multimeter so as to keep the list in one spot. I hope to save someone grief or injury by compiling this information.

A list of mulitmeters that  appear to be properly designed and can be recommended is here:
http://www.eevblog.com/forum/product-reviews-photos-and-discussion/a-list-of-recommended-multimeters/

Please post the manufacturer, model, CAT ratings, fuse type and voltage, any images that support a suspected failing in meeting the specifications of the CAT rating, or ANY other information that causes suspicion that the CAT rating is not being met.

The criteria, in part, for these variations from meeting the ratings can be gleaned from here:
http://www.eevblog.com/forum/projects-designs-and-technical-stuff/cat-ratings-and-interpretation/
The main criteria is that all inputs must be able to withstand the maximum CAT ratings in all modes of operation, connected incorrectly or not, without harming the user. Current measurement protection must meet the CAT voltage rating as well, in other words fuses used must be rated for the maximum CAT rating on the meter.

If you have a meter that claims it is UL listed, you can search to see if it actually by searching for its certification here: http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/index.html  (thanks to grenet for the link). Each UL listed item will have a UL  sticker on the piece of equipment. If you do not find this sticker then you probably have a fake UL listing on the equipment and it is not to be trusted until the listing can be verified using the link previously mentioned. A UL rating is no guarantee that the manufacturer continues to make the meter with any level of quality or the same way. Different countries also have their own standards. If a meter has a UL listing it does not guarantee that the meter actually meets its current CAT ratings claim according to the most recent CAT rating rules. For example the Extech EX330 is UL listed but does not meet the most recent rules for its claimed CAT rating.


Fluke do not recommended using the CE mark as a guide:
http://support.fluke.com/educators/Download/Asset/2096653_6003_ENG_D_W.PDF
They suggest UL, CSA, or TUV independent test markings.
(as per Dave's post)

Yes, I asked Dave if this was a good idea and he said he had no objections to this.

It seems to me that listing meters with flaws is easier than proving compliance. Anyone can demonstrate a problem, almost no one here can prove compliance.

This list can never be comprehensive because there are so many junk meters on the market that it is impossible to list them all. Please use the information here to assist in assessing a meter for use on any high energy circuit even if you do not open the meter and provide a new submission. Generally one should never rely on the markings on a meter to truly reflect its safety.

Some people have been modifying fuse holders and adding over voltage protection components to their meters in an attempt to improve the safety of the meter. Adding better fuses is probably never a bad idea but adding over voltage protection components might not be a good idea. It is possible that the over voltage devices were omitted to achieve safety and not to avoid cost. Perhaps an MOV exploded during testing but when the meter was tested without the MOV the meter passed the test.

Just because a meter is not listed here does not imply it is safe or that it meets its CAT rating, it just means it is not listed. Many brands are just "rebranding" of other meters. Uni-Trend meters are also sold as Tenma, Voltcraft, and other brands for example


The list:

Uni-Trend   UT71E (all A,B,C,D,E)  CatIII/1000V  CATIV/600V  glass fuses used on current ranges with rating of 250V, battery lead with 600V insulated wires touching unprotected circuit board trace for Volts/Ohms input, might be an issue, might not. No indication on face of meter of low voltage fuses. (submitted by lightages)

Uni-Trend UT61E (all A,B,C,D,E) CATIII/1000V  CATIV/600V   ceramic fuses rated at 250V used on current ranges with 250V voltage warning on meter. Be aware that the UT61E has a different version available in Europe. It did not pass the labelled CATIV/600V CATIII/1000V ratings. The revised version is now rated at CATII/600V and CATIII/300V and has upgraded fuses and more input protection. The safety of this meter is a complete unknown now (submitted by lightages)

Victor VC9806+  CATIII/1000V   glass fuses used on current ranges with rating of 250V, battery within clearance allowance for 1000V from fuses, no indication on current inputs of voltage limitations. (submitted by lightages)

Uni-Trend UT33C   CATI/600V CATII/300V  10A range unfused, MA range glass fused with rating of 250V with warning of maximum 500V to be applied on the common volt/ohm/ma current inputs. (submitted by lightages)

Vichy VC99   CATII/1000V  Current ranges use glass fuses rated at 250v with no warning of lower voltage, insufficient creepage distance from fuses to other parts, battery wire with unrated insulation passing through circuit board in contact with high current range circuit trace before fuse. (Submitted by T4P and review by electronupdate)

Minipa ET-997   CATII/1000V   20A range has glass fuse rated for 250V with no warning of lower voltage. (Submitted by T4P, teardown by metalphreak)

Mastech MS8218     CATIII/1000V  Current ranges have ceramic fuses rated for 500V with no warning of lower voltage (Submitted by T4P, review by mjlorton)

Extech EX330   CATIII/600V CATII/1000V  Current ranges have glass fuses rated for 250V with no warning of lower voltage (Submitted by T4P, reviewed by Dave Jones) Additional information and reviews on different Extechs show that Extech EX series are to be avoided in general. The quality control appears to be so bad that parts are coming loose inside some meters from the factory, amongst other problems.

Elenco M-2625 also Jaycar Digitech QM1535  CATII/600V?  MA current range has glass fuse rated for 250V with no warning of lower voltage. (Submitted by T4P, reviewed by Dave Jones)

Global Specialties Pro-50  CAT?, stated 1000VDC/700VAC MAX, 10A range not fused, MA range has glass fuse rated for 250V with no warning of lower voltage. Technically this meter appears to not be CAT rated so no implied safety rating(Submitted by T4P, reviewed by Dave Jones)

UNI-T UT90A CATII/1000V  CATIII/600V   ceramic fuses rated at 250V used on current ranges with 250V voltage warning on meter.   3 PTCs for input protection (Submitted by T4P)

UNI-T UT90C CATII/1000V  CATIII/600V   GLASS fuses rated at 250V used on current ranges with 250V voltage warning on meter. Some diodes to protect mA range? and 3 PTCs for input protection (Submitted by T4P)

Ideal 61-342  CATIII/600V  Ceramic fuse used on MA range rated for 500V with no warning of lower voltage fuse. Technically this is a non-compliance to standards but a minor and probably inconsequential one. (Submitted by Lightages, reviewed by Dave Jones)

BK Precision 2709B/2712  CATIII/600V CATII/1000V  Ceramic fuses used on both current ranges rated at 500V with no warning on meter. (Submitted by Lightages, reviewed by Dave Jones and 2712 by carloscuev)

Any Meter with the model number "830" All of these low priced meters are junk just waiting to blow up in your hand. (Submitted by Lightages)

Uni-Trend UT120C CATII/600V   Self recovery 250V 400mA fuse over current protector on milliamps range. Reviewed by Wytnucls here http://www.eevblog.com/forum/reviews/uni-t-ut120c-review-and-tear-down/ (Submitted by Lightages)

Brymen BM867 CATIV/1000V   Fuses rated only for 600V which is strange because the bigger brother BM869 which is built the same way has 1000V fuses. It appears that this problem can be corrected merely by installing the higher rated fuses. Reviews by mjlorton on his website www.mjlorton.com and here by iloveelectronics http://www.eevblog.com/forum/reviews/brymen-bm-867-teardown-pictures/ (Submitted by Lightages)

Amprobe AM-140-A CATIV/600V CATIII/1000V  for voltage and lower rated for current. Fuses rated only for 600V which is strange because the bigger brother AM-160-A which is built the same way has 1000V fuses. It does state in the specs that the current range has a lower rating but it is not permitted to do so in the current CAT ratings standards. It appears that this problem can be corrected merely by installing the higher rated fuses. Review by jwrtiger http://www.eevblog.com/forum/reviews/amprobe-am-140-a/msg155623/#msg155623 (Submitted by Lightages)

UEi DM5B No CAT rating but claimed 500V safety while using fuses of 250V. (Submitted by Wytnucls)

Mastercraft sold by Canadian Tire A company named Canadian Tire in Canada rebrands and sells many different multimeters over the years and almost all of them do not come close to meeting any safety standard. (Submitted by 2dfx)

Amrpobe AM-220/240 CATIII/600V with fuses rated only for 250V with warning of lower rating on meter. This made worse by the fact that the order of the input jacks have been changed which could lead to errors in use, and that the MA range shares a common jack with the V/ohms range.(Submitted by ivan747)

Digitek DT-2843R CATIII/600V with fuses rated only for 250V with warning of lower rating on meter. Reviewed by Lightages here: http://www.eevblog.com/forum/testgear/review-digitek-dt-2843r-trms-for-less/ (Submitted by Lightages)

Digitek DT-4000ZC / TekPower TP4000ZC CATIII/600V with fuses rated only for 250V with warning of lower rating on meter. Reviewed by mjlorton.com  (Submitted by Lightages)

Elenco M-2666K Rated 1000V (No CAT rating implied) with fuse rated only for 250V with no warning of lower rating on meter, 20A range unfused. (Submitted by rexxar)

Mastech MS8229 / Protek 6300 CATIII/600V CATII/1000V with fuses rated only for 500V with no warning of lower rating on meter. (Submitted by madsci)


« Last Edit: September 28, 2013, 04:10:27 am by Lightages »
 
The following users thanked this post: Mek

alm

  • Guest
Wouldn't it be more efficient to list all of the instruments that do conform to safety standards? Since the CE mark requires conformity to EN61010 for multimeters, I would expect essentially any cheap multimeter and probably many of the < $100 meters sold in the EU to be in violation unless explicitly limited to SELV. Just the lack of over voltage category markings would be a violation, not to mention the fact that they may not even conform to CAT I.
 

Offline Astroplio

  • Regular Contributor
  • *
  • Posts: 58
  • Country: gr
    • Welcome to myrobots
Not a bad idea for this thread, but shouldn't we also consider the quality/safety of their probes?
And if yes, then how can we comment on that? It looks to me it is hard to tell, but I personally would never touch mains voltage with a cheap multimeter's leads, just battery powered circuits.

Also it would be cool if people could advise for improvements of listed instruments here, i.e. a HRC fuse replacement could be all that is needed in some of these DMMs.

Thanks
George
 

alm

  • Guest
I don't think there is any way to tell what needs to be changed without torture tests. If they skimped on the fuses, they may as well skimped on other critical areas like clearance, quality of components and enclosure. Just replacing one critical component may not be enough. It's much easier to determine if something definitely does not meet spec (glass fuse, insufficient clearance) than it is to guarantee that something will pass the relevant tests.
 

Offline Wytnucls

  • Super Contributor
  • ***
  • Posts: 2833
  • Country: be
Wouldn't it be more efficient to list all of the instruments that do conform to safety standards? Since the CE mark requires conformity to EN61010 for multimeters, I would expect essentially any cheap multimeter and probably many of the < $100 meters sold in the EU to be in violation unless explicitly limited to SELV. Just the lack of over voltage category markings would be a violation, not to mention the fact that they may not even conform to CAT I.
I agree that it would be more efficient to list the meters that qualify, as that club is far smaller, in my view.
Also, remember that these regulations changed recently and we don't know what the specifications were previously.
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
UNI-T, Victor, Mastech does it to cut costs, it's any china's company policy.
Okay, here's more
MS8218 (The socket's was for a 6.3x32)
VC97/99 (the one dave reviewed)
Minipa ET-997 (Yes, search for it on eevblog)
And basically all of Victor meters, UNI-T and Minipa
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
Wouldn't it be more efficient to list all of the instruments that do conform to safety standards?

Seeing as I cannot personally test, nor can most others, the compliance to the CAT ratings stated on the meter, it is much easier to list any meter that has glaring obvious failures to match the CAT rating criteria. Stating the meter does meet CAT ratings is a very big undertaking whilst listing obvious flaws is easy for anyone to do.

Another thing is that claiming that a meter is safe here could open anyone who makes that claim to liability should someone get injured using that model of meter.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
Not a bad idea for this thread, but shouldn't we also consider the quality/safety of their probes?
And if yes, then how can we comment on that?
Yes of course, any flaw can be listed and described as I have mentioned. Just add a line of description of the problem.

Also it would be cool if people could advise for improvements of listed instruments here, i.e. a HRC fuse replacement could be all that is needed in some of these DMMs.

I would be happy for people to add any information or tips they have for improving the safety of their meter. One must realize that adding things does not necessarily make a meter safer. That omitted part might have been omitted because IT became the hazard under testing and removing it from the meter made it safer. An example might be when a manufacturer omits a voltage limiting device like a MOV because the MOV exploded during the testing and ruptured the case.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
UNI-T, Victor, Mastech does it to cut costs, it's any china's company policy.
Okay, here's more
MS8218 (The socket's was for a 6.3x32)
VC97/99 (the one dave reviewed)
Minipa ET-997 (Yes, search for it on eevblog)
And basically all of Victor meters, UNI-T and Minipa

Thanks for the additions T4P, but I request that if you find a meter that has obvious flaws that you describe what is wrong with them as I have demonstrated in my first post. If everyone just adds a meter with no description of what is wrong it can take me a long time to find the meter online, look at all the reviews or tear downs, and try to guess what you saw as a flaw.

Of course if anyone has links to reviews or tear downs or images of the offending meters the links would be welcome too.
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 11759
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
sounds like a good idea to me, and we know what happens when stuff is listed on the net as bad, companies start to think about fixing it.
https://www.simonselectronics.co.uk/shop New stock now in of EEVblog Brymen 235 and uCurrent Gold, Now selling a selection of Probe Master probes
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 26344
  • Country: au
    • EEVblog
Wouldn't it be more efficient to list all of the instruments that do conform to safety standards? Since the CE mark requires conformity to EN61010 for multimeters

Fluke do not recommended using the CE mark as a guide:
http://support.fluke.com/educators/Download/Asset/2096653_6003_ENG_D_W.PDF
They suggest UL, CSA, or TUV independent test markings.

Dave.
 

Offline Matje

  • Regular Contributor
  • *
  • Posts: 127
Revised: October 27 2012  21h15 UT

Uni-Trend UT61E CATIII/1000V  CATIV/600V   ceramic fuses rated at 250V used on current ranges with 250V voltage warning on meter


Hmm, could it be that these differ between locales? Because the one I got here in Germany doesn't mention 250V, only 300V and 600V. I didn't open it to check the fuses though, the manual does indeed say 250V. I won't connect it to any CATIII or IV installations either...

Where on the DMM is the warning located, image?
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
 

alm

  • Guest
Wouldn't it be more efficient to list all of the instruments that do conform to safety standards? Since the CE mark requires conformity to EN61010 for multimeters

Fluke do not recommended using the CE mark as a guide:
http://support.fluke.com/educators/Download/Asset/2096653_6003_ENG_D_W.PDF
They suggest UL, CSA, or TUV independent test markings.
If you would have read until the end of the sentence that you truncated in your quote, you would have noticed that I wasn't at all suggesting relying on the CE mark. But since declaring CE conformity for a DMM requires conformity to EN61010, any CE marked DMM should be EN61010 compliant, regardless of any further markings or claims.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
But since declaring CE conformity for a DMM requires conformity to EN61010, any CE marked DMM should be EN61010 compliant, regardless of any further markings or claims.

Except CE markings do not require that a 3rd party do the compliance testing. Any company can put a CE mark on their equipment if they believe, rightly or wrongly, that the equipment conforms to the standard. Its is obvious that many don't even with the CE mark.
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
UNI-T, Victor, Mastech does it to cut costs, it's any china's company policy.
Okay, here's more
MS8218 (The socket's was for a 6.3x32)
VC97/99 (the one dave reviewed)
Minipa ET-997 (Yes, search for it on eevblog)
And basically all of Victor meters, UNI-T and Minipa

Thanks for the additions T4P, but I request that if you find a meter that has obvious flaws that you describe what is wrong with them as I have demonstrated in my first post. If everyone just adds a meter with no description of what is wrong it can take me a long time to find the meter online, look at all the reviews or tear downs, and try to guess what you saw as a flaw.

Of course if anyone has links to reviews or tear downs or images of the offending meters the links would be welcome too.
Here's a few problems with the ET-997, mA fuse is actually a polyfuse
MS8218 : Wrong fuse fitted, that's a BS1362 fuse
VC99 : Glass fuses as such ...
Extech EX330 : GLASS FUSES!
The elenco one dave reviewed : GLASS FUSES!
GS PRO-50 : Glass fuses
I even wonder how EX330 won the $50 shootout ... if only UT61E had lower prices back then, that would be the clear winner
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
T4P

I appreciate the submissions, but you could save me a lot of time trying to find the exact details of each meter if you would include those details in your submissions. Look at the list and see how I am doing this. Thanks again
 

Offline Simon

  • Global Moderator
  • *****
  • Posts: 11759
  • Country: gb
  • Did that just blow up? No? might work after all !!
    • Simon's Electronics
CE marking is a joke and a farce, there is the "C E" mark, the real one and there is the "CE" mark that means china export (well we know what they hope we think it will mean).
https://www.simonselectronics.co.uk/shop New stock now in of EEVblog Brymen 235 and uCurrent Gold, Now selling a selection of Probe Master probes
 

alm

  • Guest
OK, one last try, since people appear to insist on inferring from my words that the CE mark is somehow proof of safety.

We all know that none of those cheap multimeters have a snowball's chance in hell of meeting IEC/EN 61010 unless limited to 30 Vrms or so. If the distributor (note that CE markings by Chinese manufacturers are invalid anyway) adds a CE mark, then that means they declare it to be compliant with IEC/EN 61010. All these meters therefore belong on this list. Since they are usually sold under lots of different brand names, this would be a pretty long list.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
I certainly did not think you were saying the CE mark was something to follow. Yes I know that this list could be infinitely long, but I am willing to put the work in to keep compiling the list. I am sure the more popular meters will get listed and it might help some newbies make a better purchasing decision and maybe could save someone some injury.
 

Offline T4P

  • Super Contributor
  • ***
  • Posts: 3706
  • Country: sg
    • T4P
Sorry about that, i'll head out and grab these following meters :
VC8145
UT33D
UT136C (China market only)
UT204A
UT511 (the shipping weight is 3.85kgs for god's sake!)

Should make for a nice cat rating database (UT511 will wait, ain't cheap)

UNI-T UT90A CATII/1000V  CATIII/600V   ceramic fuses rated at 250V used on current ranges with 250V voltage warning on meter.   3 PTCs for input protection
UNI-T UT90C CATII/1000V  CATIII/600V   GLASS fuses rated at 250V used on current ranges with 250V voltage warning on meter. Some diodes (WAUUWWWW!) to protect mA range? and 3 PTCs for input protection
 

Offline Neilm

  • Super Contributor
  • ***
  • Posts: 1350
  • Country: gb
CE marking is a joke and a farce, there is the "C E" mark, the real one and there is the "CE" mark that means china export (well we know what they hope we think it will mean).

The CE mark for safety will remain a joke unless local regulatory bodies start enforcing it. There have not been many cases in the UK that I am aware of where non-compliant meters were removed from the market. When they are, the issue should be published in as many trade issues as possible to make the fact that they are taking action as public as possible.

What is the state in other countries? I know that several non EU countries have complained about non compliant meters on sale.

Neil
Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe. - Albert Einstein
 

Offline Ivanko1

  • Contributor
  • Posts: 35
Uni-Trend UT61E (all A,B,C,D,E) CATIII/1000V  CATIV/600V   ceramic fuses rated at 250V used on current ranges with 250V voltage warning on meter. (submitted by lightages)
Well... my Uni-T 61E from China, has 1A and 10A ceramic fuses, type BS1362, without any voltage. So I think it's trully 1000V fuses, unless someone proves the opposite.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4293
  • Country: ca
  • Canadian po
BS1362 fuses are rated at 250V, so it is obvious that are not meant to be used above that voltage.
 

Offline Ivanko1

  • Contributor
  • Posts: 35
Ok, so what to do now, if I need measure sbout 380-400V?
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf