Author Topic: Multimeters that do not appear to meet their safety specs. (updated frequently)  (Read 155933 times)

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Offline PedroDaGr8

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What products does Fluke currently offer that you consider duds and why?
   
By doing their homework. Every company has dud models (even Fluke has had a few).

Amprobe has two models which are duds and loads of models that are safe and reliable. Even then, the two duds might have been updated or EOL'd I am not sure.

Very few ppl recommend Extech anymore, their QC is quite bad and getting worse. You just have too see Joe Smith's comparison of new versus old Extech.

I used past tense "has had", currently while I am not a fan of the 11x series I think calling it a dud would be a huge exaggeration. I am referring to some issues they have had in the past. One example being their ill-fated first attempt at outsourcing production to China with one of the 77 series meters. It was a huge dud and is well known for not even being CLOSE to Fluke's standards. It tended to drift, had build quality issues etc.
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves, "You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." -George Carlin
 

Offline mikerj

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So whats the danger with getting one of these multimeters and using them on your everyday small electronics like arduinos?

There's no real danger at all in using them for low voltage, low current stuff.  About the worst that's likely to happen is having bad readings caused by crappy sockets and probes etc. or having such a high burden voltage on mA range that your circuit fails to work.
 

Offline mos6502

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So whats the danger with getting one of these multimeters and using them on your everyday small electronics like arduinos?

The danger is that one day, maybe you or someone else forgets about how dangerous this meter is (since it nonchalantly says "1000VDC" on the front) and decides to measure some stuff on a breaker panel, resulting in a one way trip to the morgue or at the very least the nickname "Mr. Crispyfingers".
for(;;);
 
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Offline Mek

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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)
I have this one. Thanks for this information. One little point: it's "Vici", not "Vichy" :)
 

Offline Macbeth

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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)
I have this one. Thanks for this information. One little point: it's "Vici", not "Vichy" :)
Your's might be, but mine is Vichy VC99. I think they had to change to Vici after learning that Vichy = Nazi collaborators in France and want to sell their meters over in the EU. Of course more realistically is someone else has pirated the IP and modified it a bit and went in to production as yet another "Fluke competitor" but also riding on the coat-tails of Vichy.  :-DD :palm:
 

Offline baastrup

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How about uni-t 139c is that oki?
 

Offline Lightages

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How about uni-t 139c is that oki?

The UT139C seems to be a fairly well built meter. Uni-T claims it meets IEC/EN 61010-1 with a CAT rating CATIII/600V. It is possible that it might actual meet these standards, but Uni-T has not provided any third party certifications. Given that Uni-T has rated many models with CAT ratings that are obviously not possible and the UT61E was redesigned and derated at the same time so as to be able to be sold in Europe, I would err on the side of assuming that the UT139C doesn't actually meet the ratings until proven otherwise.

Having said that I would still recommend this as a decently protected meter for general electronics and home electrical work. I would not use it in a CATII environment though. You can also see tests done by Joe Q Smith here on the forums. He has been torturing many meters to see how they stand up but remember his tests are not confirmation nor disproof that any meter actually meets a specific CAT rating. Some of the failures show that some meters are obviously rated falsely but his tests are not official.


« Last Edit: January 27, 2017, 04:07:59 pm by Lightages »
 
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Offline trantula

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 :-DD
Best safety spects ever watch and learn..That is how the job is done..... :palm:...



 
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Offline dinoboy

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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)
I don't know how to test the safety of the European version but i do trust the lower ratings certified by the German Professionals:
http://www.eevblog.com/forum/testgear/uni-t-ut61e-multimeter-teardown-photos/msg1291236/#msg1291236

"complete unknown" maybe to you. Just ask the 2 institutes about the European version. They tested the safety, they certified the safety.

They will know.

Good luck.

Bye.
 

Offline Pawelr98

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:-DD
Best safety spects ever watch and learn..That is how the job is done..... :palm:...

It's just how things are in this part of the world.

This is my cheap digital meter. I paid 19PLN for it.This was around 5USD at the time.

Vacuum tube radio transformer. Anode windings in series (2x300V in series but also 250V into 220V primary).

Usually I use this meter:

1970 Mera UM3a
1% accuracy for DC range, 1.5% accuracy for AC range


AC range is a bit borked (most likely the oxide rectifier is done) so I don't really use it for AC measurement (other than current range where I have a certain correction ratio).
 

Offline najrao

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Since there must be literally millions of unsafe multimeters out there,  it occurs to me there is a case for some enterprising guy to come out with "pluggable" high rupturing capacity fuses, which just attach at one end to the 10A or xxxmA sockets on the meter. The internal fuses can then be replaced by links.The other end could be a high quality probe lead. Such a source could also be an answer to the extortionist price charged by the original manufacturers for replacement fuses.
The V-ohms-*** connection should not need separate fusing, as it is almost always protected by current limiting elements.
This may not address all the lack-of-safety issues, but may be accepted by quite some safety conscious users.
 

Offline ChrisLX200

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Since there must be literally millions of unsafe multimeters out there,  it occurs to me there is a case for some enterprising guy to come out with "pluggable" high rupturing capacity fuses, which just attach at one end to the 10A or xxxmA sockets on the meter. The internal fuses can then be replaced by links.The other end could be a high quality probe lead. Such a source could also be an answer to the extortionist price charged by the original manufacturers for replacement fuses.
The V-ohms-*** connection should not need separate fusing, as it is almost always protected by current limiting elements.
This may not address all the lack-of-safety issues, but may be accepted by quite some safety conscious users.

You can buy probes with a built-in fuse.
 

Online Gyro

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Amazing how easy it is to meet CatIV 600V on Amazon these days!  :palm:

https://www.amazon.co.uk/SURPEER-Multimeter-Digital-multimeter-Voltmeter/dp/B073VLL33N/
Chris

"Victor Meldrew, the Crimson Avenger!"
 

Offline exit_failure

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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)

Brymen apparently upgraded the fuses in their BM867s. I got mine this April from welectron and it had proper 1000V rated Bussmann fuses in it. (DMM-B-11A and DMM-B-44/100R)
 

Online Specmaster

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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)

Brymen apparently upgraded the fuses in their BM867s. I got mine this April from welectron and it had proper 1000V rated Bussmann fuses in it. (DMM-B-11A and DMM-B-44/100R)
Just checked the fuses in mine and I can confirm that are 1,000v rated as well, I really love this meter it is well worth anyone looking at this as a real serious meter and anyone overlooking it is seriously burying their head in the sand.
Who let Murphy in?
 

Offline AceAK

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Hi everyone,

As I was reading through the thread, I realized Uni-Trend/Uni-T multimeters keep popping up quite frequently. The company, in general, received a pretty bad rap and users were advised to avoid using Uni-T multimeters for mains voltage.

What I found was pretty surprising. Uni-Trend actually has so many of their DMMs tested and listed, while not under UL, but under yet another pretty reputable lab - ETL. The link is here: https://ramuk.intertekconnect.com/WebClients/ITS/DLP/products.nsf/4c8700f3b75987a08525777700583333/f75b2aea8bd09b8a862582dd0024a320?OpenDocument

Even the Uni-Trend website provides the certificate proofs. I did a check on UT139C on their website and clicked Download Manual, then clicked UT139C ETL Certificate. Pretty convincing document there.

If ETL says it is safe, it is safe, right? But I also took into account the previous negative comments about Uni-Trend in this thread and could not help but wonder could we really trust the independent laboratories (incl. the reputable ones) for Uni-Trends' or anybody's CAT Ratings for that matter. However, even Dave Jones chose to use ETL for his Brymens. So...well, I am confused.

I don't think Uni-Trend would pay so much money to ETL just to change to lower quality components for their multimeters downstream merely for higher profit margins. Even if Uni-Trend engages such cost-cutting approach, ETL for sure will whack them hard if their reputation is compromised by Uni-Trend. At the end of the day, it just does not make any business sense for Uni-Trend to do so.

And if Uni-Trend really upholds their listing standards and the independent laboratories could be trusted, could it be that the previous analysis of their multimeters not being safe is mistaken, at least partially so?

Hope to hear all your views.

Cheers.
« Last Edit: August 14, 2018, 06:40:47 am by AceAK »
 

Offline joeqsmith

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Take a look at the UT61E for example.  The link you provide lists it.   If you do a search on this site, you will find more than one flavor of this meter.  There are some major differences between them.   After you look into this, ask yourself if you feel that all of these different flavors of the 61E are actually certified and if so, how come they add so much cost to one flavor of it rather than just making more profit.   If you check the price, you will find a fairly large difference.  If you come to the conclusion that some of their UT61Es may indeed have been certified and others not, ask yourself how do they get away with it and what's really the point of the certification if you can't trust it?

Do you think the lower end companies do any sort of annual inspection of their product?  Or do you think there are companies that will get a product certified, then change the design over and over, maybe to reduce cost, and never have it certified again.   Would you have a problem with this? 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline AceAK

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There is inevitably a conflict of interest, I supposed. After all, companies pay the independent laboratories to test their products for certifications.

But if independent testing laboratories such as UL and ETL are accorded OSHA's (Occupational Safety & Health Administration) recognition as NRTL (Nationally Recognized Testing Laboratory), it is not impossible for the government to enforce the labs to deny certification testings to companies which have been suspected or guilty of changing their components after being certified, where failure to do so may result in their OSHA's recognition being revoked. The lab could also revoked the certification given to these companies' products. The labs would naturally only do that if they value their OSHA's recognition more than the paychecks from their customers. Not sure if I am being too naive or harsh here.

Of course, the companies may argue that lemons may exist in their certified models. But it was pretty obvious of Uni-Trend's non-compliance when there were so many reviews/reports of their European UT61E batch being constructed differently than the Asian UT61E, which had worse components but received better CAT ratings. Cough cough, ETL...so much for being OSHA's NRTL.

The issue is there is no real "policeman" at the moment. Therefore, I support the calling out of dubious CAT-ratings meters in this thread as a more direct move rather than waiting for the government to stretch its heavy bureaucratic hand in this matter. May the market forces lead the Chinese manufacturers to the right path.

With that being said, we must realize a large portion of the electronic hobbyists don't see the risks of using Chinese meters as they usually deal with low voltages - a point which I may not totally agree but can understand. The price margin between a brand name (US/German/Japan ones) and the Chinese ones is a huge factor. Can the pricing of brand name products ever compete with the Chinese ones? I believe they can to a certain extent, given their insane markups. But I doubt they would want to, given the investors-heavy burden of these brand name companies. The Chinese companies have less of such problems as they based their profits on volume sales.

From what I see, the consistent comment here is "Cheap multimeters have their place but I would only trust my properly-certified meters for mains". In other words, the users buy both the cheap and expensive meters for different uses and the companies win. The market's desire for safer Chinese meters and cheaper brand name meters seems to be generally ignored. From the Chinese market, so far, only Uni-T has less than a handful of more believable CAT-Ratings meters like UT139C. I wonder why. Fluke has only caved in a bit to the market producing lower-priced Chinese meters. However, the price margin is still quite apparent to many. Brymen is so successful in this forum possibly due to the battle between the typical brand names vs Chinese companies and of course, due to our Dave Jones. I don't know how much the companies listen but the least we must do is speak. So kudos to all those who contribute to this forum and Youtube (sadly, not available in China).
« Last Edit: August 18, 2018, 05:52:26 am by AceAK »
 

Online rsjsouza

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There is inevitably a conflict of interest, I supposed. After all, companies pay the independent laboratories to test their products for certifications.

But if independent testing laboratories such as UL and ETL are accorded OSHA's (Occupational Safety & Health Administration) recognition as NRTL (Nationally Recognized Testing Laboratory), it is not impossible for the government to enforce the labs to deny certification testings to companies which have been suspected or guilty of changing their components after being certified, where failure to do so may result in their OSHA's recognition being revoked. The lab could also revoked the certification given to these companies' products. The labs would naturally only do that if they value their OSHA's recognition more than the paychecks from their customers. Not sure if I am being too naive or harsh here.
There is a difference between being tested and certified and carrying a "mark" on its meters. The test and certification is a "point release" deal - i.e., they certify and test samples of the product (all provided by the manufacturer) against a specific regulation and write up a document that covers the methods used and the standards tested. That's it. No further relationship between the two companies. That costs real $$$ once.

When the product carries a "mark", it is fully "listed" - i.e., during the time the listing is valid, the certification agency will re-certify the products released by the manufacturer from time to time to be sure the listing is still valid. Also, IIRC the manufacturing plant will also receive inspections from the certification agency to guarantee this still meets the conditions when the first inspection took place. That costs real money over time.

What happens is that it is not really uncommon for manufacturers slip on quality or reduce costs to the point of maintaining minimum functionality - especially if they are operating in the ultra low margin markets. If their product is liste, they are forced to maintain the quality and functional aspects of the product.

A government could in theory enforce the companies to refrain from doing business with regular offenders, and I am pretty sure they do for the really bad ones (thus the slew of false markings around), but I suspect the interest rapidly diminishes given the overall market is really much larger than the offenders. Also, the leverage rapidly diminishes since several of these companies are foreign to their markets and the certification agencies' headquarters (that is one of the points that Señor Frump is trying to bring to the table with the recent brouhaha on international trade tariffs, but I digress).
« Last Edit: September 11, 2018, 12:45:59 am by rsjsouza »
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