EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Topic started by: EEVblog on July 15, 2017, 10:58:27 am

Title: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 15, 2017, 10:58:27 am
Dave looks at the $25 ANENG AN8008 Multimeter
It has some unusually low ranges making it ideal for electronics use. Or is it?

http://www.youtube.com/watch?v=xdGQEVdxmQQ (http://www.youtube.com/watch?v=xdGQEVdxmQQ)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: sleemanj on July 15, 2017, 11:05:29 am
For those who have not seen it, the ongoing discussion... 
an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter (http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: retrolefty on July 15, 2017, 11:29:50 am
Maybe not your intention but I just bought one based on your review. $21 delivered and shipped from a US seller. Man compared to what I paid for a Simpson 260 in the 60s in real dollars, boy has electronics come a long way.? While I own a couple of old Fluke 87s, this seems too handy to pass on.

So best bang for buck hobbyist meter ever?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 15, 2017, 11:30:20 am
That is amazing for the price.
It is also an amazing amount of multimeter, in such a small package.
Not using 9V PP3 batteries, is probably also an advantage (ignoring diode test voltage) for some people. As AAA's can be cheaper and more available.
From the video, the backlight seems very effective, as well.
Quite an assortment of probes, tips, accessories including pouch as well.

Those tiny fuses are both really cute, and hugely dangerous, at the same time, if you understand what I mean.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on July 15, 2017, 11:59:36 am
Quite interesting meter for the price, and the accessories complete the package quite well.

One additional detail: a few months ago I bought an UT136 on the same premises (nice meter for the price) - I did one mistake and the ohms/diode/continuity ranges are gone. I know how to repair that but, if the same happens with this meter, it can be very frustrating for beginners. Due to the lack of protection this will most probably be the same on this meter.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 15, 2017, 12:11:16 pm
I wonder if any of the sellers will take a screenshot of the thumbs up in front of the meter and add it to their for sale listing :P.

As usual, why the 1000V CAT II / 600V CAT III nonsense? It could almost have been a half-decent meter for beginners or as second meter for low level signals if clearly marked CAT I 50 V and ranges limited to 50 V, and might even meet those safety requirements. The main downside would have been the missing current ranges.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fsck on July 15, 2017, 12:42:41 pm
I wonder if any of the sellers will take a screenshot of the thumbs up in front of the meter and add it to their for sale listing :P.

As usual, why the 1000V CAT II / 600V CAT III nonsense? It could almost have been a half-decent meter for beginners or as second meter for low level signals if clearly marked CAT I 50 V and ranges limited to 50 V, and might even meet those safety requirements. The main downside would have been the missing current ranges.

marketing: everybody else has it, so we should too.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: bjcuizon on July 15, 2017, 12:53:28 pm
Wow! It's such a decent little meter with 10000 counts...I wish it had the µA range though :-DMM. But overall, its really good for its price. :-+
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: sleemanj on July 15, 2017, 01:27:13 pm
As usual, why the 1000V CAT II / 600V CAT III nonsense?

Marketing.

I agree it would be better if meters were just honest about it.  99% of the buyers of these meters do not need 600V Cat III, ever.  The most they are, or should be, working on is Cat II.

Cat II 600V or even 300V can't be that hard to achieve legitimately, I'm sure it could.  Ideally with 5x20mm fuses though.  Why they used those stupid 10mm ones, I don't know, there's room for 5x20 in there surely.

Here in NZ, I (sometimes, not currently in stock) sell a cheap chinese meter, the ADM02 (Mastech MS8233E inside), it's just 2000 count 3.5 digit, but it's physically robust, looks good, has non-silly 5x20mm fuses, and it does what the majority of people need (except the diode test voltage is too low :-(), but one of the BIG reasons I chose that one to stock, is it's marked as Cat II 600v, and that's it.  I'm quietly hoping that BSide (or Mastech, or PeakMeter or...) takes the 8008 chipset and stuffs it into an ADM02 form with 5x20 fuses, slightly better input protection, and most importantly, that 600v CAT II marking, for $25US or less.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ejeffrey on July 15, 2017, 01:45:10 pm
Looks like a nice little meter, certainly nicer than  most of the cheap meters I have used.

One thing that I think would make a neat video is to take a handful of cheap meters with high counts but mediocre accuracy, throw them in the back of a car for a year and let them get knocked around and subject to big temperature swings, then check their accuracy again.  Its no surprise that a 10k count meter comes out of the box with <0.1% errors on most ranges.  It would be interesting to see how much they actually drift compared to the 0.5% spec.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Monkeh on July 15, 2017, 02:29:51 pm
Extend the current ranges and swap the hold button for a rel button and.. it's almost perfect. For $25. Just take a marker out and get rid of the cat ratings.

The sort of handy extra meter to keep around the bench or in the car.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 15, 2017, 03:05:22 pm
Extend the current ranges and swap the hold button for a rel button and.. it's almost perfect. For $25.

Yep, very close.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Muttley Snickers on July 15, 2017, 03:37:10 pm
Guided by the numbers it must be a popular subject with already over nine thousand views in a day, two were mine by the way just to be sure, I was in the market for a 101 or similar anyway.   :-DMM :-/O     
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 15, 2017, 03:39:41 pm
I have a Richmeter RM101 on order (a rebranded ANENG AN8001) for A$16.31 inc postage. That is half the price of the AN8008 and it has the normal mA current ranges, but not the sensitive volts and current. It does have a range button pads on the back of the PCB I think. I would love to find a way to use it. I could have paid a little more for the RM102/AN8002 with the temperature functions, but  I didn't need it.

Buying both the 8008 and 8001 is not a bad combination. You end up with two multimeters for two concurrent measurements, and you get the sensitive ranges of the AN8008 along with resistance to 60MOhms and the proper mA current ranges of the AN8001.

It would be great if they could release one meter that does it all.

If it is possible to replace the fuse holders with something bigger, I will give it a go.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: cdev on July 15, 2017, 04:45:36 pm
Dave,

products like this and an iffy economy are why, if I were you, I would not risk your future finances on the success of your meter, nomatter how good it is, we can never compete on price with the Chinese..  we shouldn't even try.

We have to work smarter, and make smarter products, not cheaper.

They will always be cheaper.   This is also why the world needs more public education, lots more of it. Even if the generic jobs most people do are going away for good.

Privatizing public education and health care so that most people are left struggling to afford it is a recipe for disaster.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 15, 2017, 06:40:22 pm
These are the golden years, when the Chinese economy matures they will want higher wages etc and the price of products will rise. At sometime in the future it will all flatten out and as you say we will all have to work smarter including the Chinese and Indians etc.
At that price I have just purchased one to keep in the car, it will replace the cheapo one already there and never used as yet, the hope is I never will need a meter in earnest in the car.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: pixelk on July 15, 2017, 06:51:56 pm
Maybe not your intention but I just bought one based on your review. $21 delivered and shipped from a US seller.

Same here ( 17,46 € delivered to EU ), It will be a honorable "backup meter" for my Extech EX330. I have very limited use for mains testing and will NEVER use it near a live socket. I'm more concerned by the somewhat flimsy socket plugs.

Sometime you just don't need features (as long as you're aware of the risks & limitation of a chinesium enriched product ). DON'T USE THIS on something your life depends on, but for testing continuity, it will be good enough ;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: snoopy on July 15, 2017, 07:08:19 pm
I just checked all of my DMM's including a Fluke 87 and Protek 506. None of them have uV measurement capability. This meter is worth having for this feature alone ;)

cheers
davo
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanMacdonald on July 15, 2017, 07:24:08 pm
Looks not bad for the price. At least, having a fused 10A range is better than no protection.

Thing I advise about cheap meters is to avoid the autoranging ones because they invariably do a 'Mexican hat dance' - display a whole series of false readings - before settling.  How does this one fare in that respect? If it's a nice quick autoranger that doesn't give misleading readings before settling, than at the price it's a winner.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 15, 2017, 10:53:55 pm
Wow! It's such a decent little meter with 10000 counts...I wish it had the µA range though :-DMM. But overall, its really good for its price. :-+

Huh? It does have uA. Watch the video...

(and with 9999 digits it'll measure nA as well)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 15, 2017, 10:59:08 pm
As usual, why the 1000V CAT II / 600V CAT III nonsense? It could almost have been a half-decent meter for beginners or as second meter for low level signals if clearly marked CAT I 50 V and ranges limited to 50 V

If you're worried you can scratch off a I and get a more realistic rating.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=328075;image)

Dave measured 1000V in the video, it seemed to hold up.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 15, 2017, 11:05:14 pm
If I dindn't already have a Fluke 101, I would buy this thing :-+
Although I woudn't measure mains with it, but the Fluke 101 comes with no current ranges.

Edit: some corrections
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 15, 2017, 11:09:35 pm
If you're worried you can scratch off a I and get a more realistic rating.
[...]
Dave measured 1000V in the video, it seemed to hold up.
Handling 1000 V AC does not come close to satisfying the requirements for 1000 V CAT I. 1000 V CAT I requires safely handling a 4000 V transient from a 30 Ohm source (12 Ohm source for 600 V CAT II). Does anyone expect those tiny fuses to handle that without arcing? The non-existent input protection? Minimal clearance?

I think you would also need to scratch away two zeroes in addition to the two I's.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 15, 2017, 11:33:05 pm
If you're worried you can scratch off a I and get a more realistic rating.
[...]
Dave measured 1000V in the video, it seemed to hold up.
Handling 1000 V AC does not come close to satisfying the requirements for 1000 V CAT I. 1000 V CAT I requires safely handling a 4000 V transient from a 30 Ohm source (12 Ohm source for 600 V CAT II).

I think you would also need to scratch away two zeroes in addition to the two I's.

I only said "more realistic".

Does anyone expect those tiny fuses to handle that without arcing? The non-existent input protection? Minimal clearance?

No.

In other news: The sibling AN8002 survived longer than a Fluke 87V in joe's electrical robustness testing. There's no reason to think this will be different, the PCBs are almost identical.

http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)

 :popcorn:

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 15, 2017, 11:54:45 pm
In other news: The sibling AN8002 survived longer than a Fluke 87V in joe's electrical robustness testing. There's no reason to think this will be different, the PCBs are almost identical.

http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)

 :popcorn:
While that is encouraging, that says little about safety. From Joe's FAQ:
Quote
Q) Are the meters that fail your tests unsafe?  They all fail in a safe manner and although non-functional it presented no safety risk in that failed condition.
 
A) I have no idea if any of the meters I have looked at would fail in a safe manner or not if tested to the IEC standards.  If you want to know if a meter is safe or not, have it tested by an accredited lab or buy one that has been certified by a third party.
 
I loosely based my testing on the IEC standards.   The tests I perform are at much lower energy levels than the meters what these standards call out. This is why we never see the explosions like you would when watching some of Fluke's internal testing.  I don't expect the general hobbyist is going to know about CAT ratings or the IEC standards. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: f4eru on July 16, 2017, 12:30:56 am

If you're worried you can scratch off a I and get a more realistic rating.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=328075;image)
Not a good idea. If you "remark" it to some non compliant safey marking, you're responsible if somebody gets hurt.
(in the EU, you're fully legally responsible now anyway if you import or resell it, which includes buying it from alibaba or ebay china, or amazon not UE)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 12:31:54 am
If I dindn't already have a Fluke 101, I would buy this thing :-+

What country are you from? Is there a law against owning both?

I bought one of these to use as a secondary meter to my old Fluke 27

(or primary, I can't promise which one will be used most in practice)

If it is possible to replace the fuse holders with something bigger, I will give it a go.
.

If you're using this in a place where you need bigger fuses, you're probably doing it wrong. When would you ever be measuring current in a 4kV transient-prone environment anyway?  :popcorn: (the current ranges are the only places the fuses are doing anything useful).

Another thing to ponder is that the battery voltage appears on the square wave output. Think about that long and hard before connecting it to mains AC with the selector in that position.  :scared:

One good thing about this meter is that they put the current ranges/square wave selections as far as possible from the "OFF" position. That's a bigger safety feature than bigger fuses will be.

Dave,

products like this and an iffy economy are why, if I were you, I would not risk your future finances on the success of your meter, nomatter how good it is, we can never compete on price with the Chinese..  we shouldn't even try.

We have to work smarter, and make smarter products, not cheaper.

A smart thing would be to add proper MOVs, PTCs and fuses and sell it for $40.

(and put temperature function instead of square wave output)


In other news: The sibling AN8002 survived longer than a Fluke 87V in joe's electrical robustness testing. There's no reason to think this will be different, the PCBs are almost identical.

http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)

 :popcorn:
While that is encouraging, that says little about safety.

I know, I'm just trolling you.

My advice for anybody who:
a) Wants to poke pieces of metal into mains sockets and distribution panels
and
b) Thinks a proper industrial meter is "too expensive"

is to get a Fluke 101. They're only $42, delivered. There's really no excuse.

Also: The multimeter is only a part of the equation. I'd prefer to use this meter on a distribution panel with gloves, face shield, hearing protection and a partner standing by with telephone in hand than a "safe" Fluke 87V without any of those things.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 02:08:58 am
If I dindn't already have a Fluke 101, I would buy this thing :-+

What country are you from? Is there a law against owning both?

I bought one of these to use as a secondary meter to my old Fluke 27

(or primary, I can't promise which one will be used most in practice)


I originally bought the Fluke 101 to always have a nice little meter with in my backpack and also the have a meter I can trust during holidays, where I can't acess the rest of my gear. Since I have that, I don't really see the need for another meter. But I use mostly a Fluke 177 or a DM3068.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 16, 2017, 02:41:28 am
My advice for anybody who:
a) Wants to poke pieces of metal into mains sockets and distribution panels
and
b) Thinks a proper industrial meter is "too expensive"

is to get a Fluke 101. They're only $42, delivered. There's really no excuse.
Well, that is more than twice as expensive :P. I would agree, if this thing would not state 'please use me on three-phase motors', i.e. CAT III 600 V, on its front panel. Then it would make a fine companion to a meter like that.

Also: The multimeter is only a part of the equation. I'd prefer to use this meter on a distribution panel with gloves, face shield, hearing protection and a partner standing by with telephone in hand than a "safe" Fluke 87V without any of those things.
Absolutely. But that is not a very fair comparison. The few hundred USD you save by going for the $20 meter does not pay for that safety equipment, especially not the partner.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: npelov on July 16, 2017, 03:31:24 am
What is the cut off voltage. Can it be used with Ni-Mh?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on July 16, 2017, 03:34:14 am
What is the cut off voltage. Can it be used with Ni-Mh?
The AN8002 model works fine with LSD NiMH cells.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 16, 2017, 06:15:30 am
20 bucks.

Just modify it with some proper input protection yourself.
And there is even a work-around for the current ranges (witch really is a bummer, i agree)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rollatorwieltje on July 16, 2017, 06:26:01 am
I would love to see what a tiny fuse like that does when shorted across mains. I suspect it's not really a problem that those fuses normally come with leads, you're probably going to need them.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: electr_peter on July 16, 2017, 06:34:40 am
It seems that volt range has [000.0 - 999.9 mV] range as well (that is, both V and mV ranges on the same switch position). Thus DMM can show [230.1 mV] or [230.1 V] - 1000 times difference in magnitude, but display only differs by a small letter.
This display behaviour can be annoying and misleading for many people. I do not like such configuration - better to have separate [V] and [mV] ranges, not a strange mix as it is.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 16, 2017, 07:08:27 am
When people talk about modifying a multimeter to make its input protection "better", I cringe. You might be able to reliably improve the sensitivity of the meter to damage and failure. Don't fool yourself into thinking that the meter is safer for the user.

Multimeters go through extensive pre-testing, and testing in approved third party labs to obtain a proper certification. Safety is not something guaranteed by design, that is why testing is done. Sure you can add resistors, MOVs, spark gaps, PTCs, fuses, etc to the input circuits and they might improve the reliability of the meter itself to withstand user errors and  unexpected transients. This is no guarantee that under the wrong circumstances that the meter won't explode and nor that your mods will have not made the meter worse for your safety.

Joe has done many tests and his thread was originally something to with matching CAT ratings, but he has edited the title to remove this association and for good reason. Joe has also modified meters to make them, the meters themselves, survive HIS tests. His tests are not safety tests. They might have a some relation to the safety of a meter but that is not his goal nor should the results infer any safety level of the meters he tests. It is quite possible, even likely, that his modified UT61E will pass CATIII/600V without any problems, but it has not been tested under the requirements for that rating and that means it actually could be a bigger bomb in your hand under the wrong circumstances than the original.

My point for ranting here is that when people casually mention modifying their meters to better the input protection they either have no idea what they are saying, have no idea what safety actually implies, but even worse they might give the casual reader the idea that modifying a multimeter is automatically a good thing and nothing could go wrong.

If a meter needs modification to make it safe, mark it as "NOT SAFE FOR FOR ELECTRICAL WORK" and/or "DOES NOT MEET ITS SAFETY RATINGS". That should be the only modification made to any meter that someone might think is safe to use in any situation other than the low energy electronics work bench. That is unless the mods are solely for added functionality or survivability on the bench.

Sure, modifying is fun, can be useful, educational, and even money saving, but it cannot imply better safety. If you modify a meter, keep it on the bench and mark it as mentioned before. It should never be used on anything higher than CATII, maybe even CATI.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 16, 2017, 07:29:04 am
I originally bought the Fluke 101 to always have a nice little meter with in my backpack and also the have a meter I can trust during holidays, where I can't acess the rest of my gear. Since I have that, I don't really see the need for another meter.

Well, depends whether "during holidays" you are more likely to measure mains voltage (which you would rather not do with the AN8008), or to measure any current (which the Fluke 101 can't do at all)...

Regards from ebastler to Rbastler, by the way!  ;)
I assume you are from the German-speaking part of Italy? Happy tinkering! (A "bastler" is "tinkerer", for all non-Germans out there.)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 07:29:58 am
I think modifying cheap gear into better one isn't worth it, because you spent time and money into creating something better and in the end it did cost the same amount as if you'd bought the more expensive one.
I see a reason in doing it, when a particular function isn't available on the more expensive multimeter for example.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 16, 2017, 07:39:18 am
My point for ranting here is that when people casually mention modifying their meters to better the input protection they either have no idea what they are saying, have no idea what safety actually implies, but even worse they might give the casual reader the idea that modifying a multimeter is automatically a good thing and nothing could go wrong.
In my professional opinion, you clearly ARE missing the point and thinking in ways of rules, not in a way of circuit design.

1- Safety tests go much further than just peoples safety.

2(a,b&c) - Safety tests are also mainly focused how to have consistent safety in production in masses.
On top of that those type of product should never fail in a professional setup (you can get very awkward and annoying situations)
Plus a company doesn't want some bizarre case in court, so they do whatever they can to provide proof that every lunatic can use their product in every thinkable (bizarre and weird) situation

Those are two VERY different things!!

Someone with enough knowledge and a clever design can even make this $20, 99.8% safe without any issues.
And that doesn't need to be expensive.

So by just ranting that people don't have clue about safety is absolutely nonsense without any context.
Than I am simply gonna rant back  8)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 16, 2017, 08:16:36 am
Someone with enough knowledge and a clever design can even make this $20, 99.8% safe without any issues.
And that doesn't need to be expensive.

Prove it. Prove it with proper safety tests done by approved safety testing facilities, testing equipment modified by people who "have enough knowledge". Prove that these modified meters are safer for the user. That is prove in what safety means in the context of CAT ratings. I also qualified the benefits of modifications but you seem to want to pick a fight over something that I didn't say.

So by just ranting that people don't have clue about safety is absolutely nonsense without any context.
Than I am simply gonna rant back  8)

Again, you are putting words in my mouth. When did I say that everyone has no idea of safety? My content is what Joe has said about his tests himself, what the IEC has said about safety tests, what Dave has said about safety and meter construction, what I have as 30+ years in safety and health education, certifications, and building equipment to safety standards and inspections by CSA and UL.

If you want to make recommendations that people should make modifications to multimeters to improve the safety of the user, then you are making dangerous recommendations unless you have certified tests to prove your assertions. In this case you are an uneducated, unscientific, and dangerous idiot.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: npelov on July 16, 2017, 08:45:21 am
Guys don't fight!
Personally I think if you need a safe multimeter - you get one. You don't fool around and try to make it any safer than it is. I tried to be friend with electricity many times and it kicks me every time. So whenever I poke at line voltage I don't take any chances. The good expensive HRC fuses have one advantage - it's less likely to blow it because you know you'll pay another $15 for new one and you are extra careful. The fuses in my Brymen are more expensive than this multimeter! Damn, I don't want to make this one safer because I'll be scared to use the current measurement and blow an expensive fuse just because I probed 5V line. You don't wear bulletproof vest when you play with water guns.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 16, 2017, 08:47:06 am
You can name all the safety certificates you want (which I am all aware off).

A very respected, smart and highly intelligent person in science and engineering with over 50 years of experience, ones told me the following (unfortunately I'm not allowed to share his name in public)

"People always say safety first. Which is very incorrect and even dangerous.
It is thinking first (just follow basic science and engineering), than safety and third is sometimes just random bad luck"

In fact, it is even proven that blindly following safety protocols can even lead to potentially more dangerous situations.
You should teach people the how and why instead.

With me a lot of people in the field are getting extremely sick of all the ridiculous so called 'safety rules'.
You can write pages about how many years of experience you have and what kind of qualifications or certificates etc, but it all simply comes down to some general science knowledge.
Because it simply doesn't make sense why nobody cares about batteries, while it doesn't cost much to kill someone very easily with a 9V battery!
I know companies/countries where someone isn't even allowed to handle a bloody standard knife anymore  |O :palm: :palm:
If people are to dumb to know what they are doing, they shouldn't be doing it in the first place.
In fact, in a lot of countries that's even how the law system work.
Which means that it's not important anymore if a product was 'unsafe', just by the fact that you were doing things you weren't qualified for cancels everything out.

Btw, with all the respect, but I don't know who brainwashed people that 'you need approved safety facilities' to test safety.
Than you simply have fallen in the big marketing trap.
You forget the reason WHY these facilities exist, with the one and only reason: cover themselves in court.
Nothing more, nothing less. That doesn't mean that other ways aren't safe.
(in fact I know many so called 'safety regulations' in some countries that are absolutely forbidden in others)
Second to that, if safety is so important, why is it SO difficult and SO expensive to get these tests done, of to even get the basic documents?
These things should be open to the public.

All of this doesn't mean that there are people out there that make these type of meters, review a lot of meters or just have a very good understanding what potential dangerous there are and how to tackle them or are just smart people with enough knowledge/resources to find that out.
These meters and safety tests are not done by unknown hyper smart aliens.

So in fact, I would ENCOURAGE people to dig into this and share it to the public because in my opinion that's even your responsibility as an engineer/scientist.
And to add something extra for the people who have so "many experience in the field", maybe it would be better to help people out, explain it how it is done properly instead of kicking people shins.
If you can make the time and energy to rant, you can also use the same time and energy to be productive instead.
Talking about proving.......




 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: digsys on July 16, 2017, 09:58:25 am
I'm NOT going to buy one ... I'm NOT going to buy one ... I'm NOT going to buy one ... I'm NOT going to buy five ... DOH !!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 16, 2017, 12:31:35 pm
When people talk about modifying a multimeter to make its input protection "better", I cringe. You might be able to reliably improve the sensitivity of the meter to damage and failure. Don't fool yourself into thinking that the meter is safer for the user.
...
Joe has done many tests and his thread was originally something to with matching CAT ratings, but he has edited the title to remove this association and for good reason. Joe has also modified meters to make them, the meters themselves, survive HIS tests. His tests are not safety tests. They might have a some relation to the safety of a meter but that is not his goal nor should the results infer any safety level of the meters he tests. It is quite possible, even likely, that his modified UT61E will pass CATIII/600V without any problems, but it has not been tested under the requirements for that rating and that means it actually could be a bigger bomb in your hand under the wrong circumstances than the original.

My point for ranting here is that when people casually mention modifying their meters to better the input protection they either have no idea what they are saying, have no idea what safety actually implies, but even worse they might give the casual reader the idea that modifying a multimeter is automatically a good thing and nothing could go wrong.
.....
Sure, modifying is fun, can be useful, educational, and even money saving, but it cannot imply better safety. If you modify a meter, keep it on the bench and mark it as mentioned before. It should never be used on anything higher than CATII, maybe even CATI.

My highly modified UNI-T UT61E is more robust, has lower burden voltage and a much low temperature coefficient than it did when I bought it.  Not to mention it's adaptive backlight and that it can measure 20A for extended periods of time.    You would have to be a complete idiot to think it was safe.   It looks more like a death trap. 

You are right that when I modify them, it is to pass my tests which are different from the IEC standards.  The main differences being the double the FWHH and much lower available energy.  The energy really only comes into play if a meter were to breakdown.  We just don't see the level of explosions you will see with a real combo generator.   However if the meter does not breakdown, that energy is absorbed by the generator (not the meter) and in these cases, I would expect the meter to handle the same levels on a certified combo generator.   This is why when we had a member repeat the testing I did on the Fluke 101 at 12KV, it had no problems.   If we took Dave's 121GW for example that failed at 1.5KV 2KV, putting it on a real surge generator we may see some action.  While the meter may not survive or be repairable after such a test, we will assume it is safe per the standard. 

I've mentioned it before that I think the majority of the safety would be mechanical.  I suspect the protection circuitry on the voltage input is really there to prevent damage to the meter, not for safety.  I have a TPI / Summit  meter that I tested and it failed just by rotating the selector switch through the settings with the 220V applied.   It's happened four times now, so fairly rare.   This meter was UL approved to meet the safety standards.  Someone wrote that companies will falsify the cert but UL does maintain an on-line database that makes it simple enough to check.     Dave's preproduction 121GW failed at 2KV with it's MOVs, PTCs and clamps.  The AN8002 (lower end version) failed at 3KV, with just a PTC and clamp.  Dave has stated that if the 121GW passes the safety tests, it's good enough. 


With me a lot of people in the field are getting extremely sick of all the ridiculous so called 'safety rules'.
You can write pages about how many years of experience you have and what kind of qualifications or certificates etc, but it all simply comes down to some general science knowledge.

.....

Btw, with all the respect, but I don't know who brainwashed people that 'you need approved safety facilities' to test safety.
Than you simply have fallen in the big marketing trap.
You forget the reason WHY these facilities exist, with the one and only reason: cover themselves in court.
Nothing more, nothing less. That doesn't mean that other ways aren't safe.
(in fact I know many so called 'safety regulations' in some countries that are absolutely forbidden in others)
Second to that, if safety is so important, why is it SO difficult and SO expensive to get these tests done, of to even get the basic documents?
These things should be open to the public.

All of this doesn't mean that there are people out there that make these type of meters, review a lot of meters or just have a very good understanding what potential dangerous there are and how to tackle them or are just smart people with enough knowledge/resources to find that out.
....

I agree that the IEC standards should be public domain.  I'm sure you are aware that the standards are more than just for safety.  My guess is you are just referring to the 61010 standard that most of the meter's documents will call out. 

The cost to setup a lab like this is going to be more overhead than most companies could afford.  Care to guess at the price of the large compliance chamber I showed? 

Interesting comment about "getting extremely sick of all the ridiculous" safety regulations.  I have to venture out of my hole from time to time and am always amazed at the level rules at some places I visit.  While many are safety related, a fair number of them are in place for process control.   Today I visited a large power plant which really gave me a whole new perspective on electrical safety.     

I agree with your comment that just because a company self certified, does not mean the product is not safe or would fail if tested at an independent lab.  But I doubt very much that this particular meter would pass the CAT III levels. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on July 16, 2017, 01:44:14 pm
When people talk about modifying a multimeter to make its input protection "better", I cringe.

So do I.

Quote
You might be able to reliably improve the sensitivity of the meter to damage and failure.

... which is not impossible, but ...

Quote
Don't fool yourself into thinking that the meter is safer for the user.
BINGO!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 16, 2017, 02:16:59 pm
Don't fool yourself into thinking that the meter is safer for the user.
BINGO!
Doesn't make much sense to me. If you make a meter safer, then it is in fact safer.

Some of us have some experience in electronic design. Issues like voltage clearance, fuse rating, etc are all understandable design problems. If I modified a meter for my own use, I would be comfortable.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: boffin on July 16, 2017, 02:41:44 pm
Given the lack of a couple important mA ranges (likely the MOST important ones), I doubt I'd be interested in this, nor recommend it.  However, does the AN8002 have those ranges?  I'm always on the lookout to suggest things to people getting started; and for under $20, the 8002 looks like it does most of what beginner makers need (including useful Freq Counter/Duty Cycle)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: sleemanj on July 16, 2017, 02:45:05 pm
Sometimes I think some people would only be satisfied if every meter was Cat IV 1000V - and even then they would worry that somebody might pick it up and connect it to a lightning rod, in a storm, in Darwin, while standing in a puddle of salt water, naked, and surrounded by crocodiles.  A Fluke would be fine in that scenario of course, patentend croc-repellant in the special yellow plastic I expect.

How many hours do people spend reading EEVBlog forum using a tablet connected to a mains charger... I wonder how well the average mains charger would fare when a 6000V impulse comes down the wire (Cat II 1000V), but we don't really give it a second thought.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 16, 2017, 02:46:08 pm
I do not think a meter that clearly lies about its safety should be recommended to beginners. I am not at all claiming that beginners need a meter designed for industrial use. I would actually be fine with a meter that can not measure mains voltages. But at least it should be honest about it, since beginners will not be able to judge this for themselves.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: sleemanj on July 16, 2017, 02:51:03 pm
.  However, does the AN8002 have those ranges?

The 8002 (RM102, KT102.... ) has a 60mA range (6000 count), so yes it will give you 2 digits after the decimal for 1-60mA before it steps up.  However it does not have uA ranges (at least not without modification?).

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 16, 2017, 03:09:54 pm
Sometimes I think some people would only be satisfied if every meter was Cat IV 1000V - and even then they would worry that somebody might pick it up and connect it to a lightning rod, in a storm, in Darwin, while standing in a puddle of salt water, naked, and surrounded by crocodiles.  A Fluke would be fine in that scenario of course, patentend croc-repellant in the special yellow plastic I expect.
Most people (including me) complain about the false labeling, giving a false sense of safety. The manufacturer was the one that brought up the ridiculous CAT III 600 V rating. In my opinion CAT I 50 V would be perfectly fine for a beginner or as a second meter for many experienced people, with the understanding that it is not to be used near high voltage or mains circuits (which a beginner should not be messing with anyway).

How many hours do people spend reading EEVBlog forum using a tablet connected to a mains charger... I wonder how well the average mains charger would fare when a 6000V impulse comes down the wire (Cat II 1000V), but we don't really give it a second thought.
First, a charger is not designed for a 1000 V circuit. So if anything, it would be CAT II 300 V (never mind that IEC61010 does not apply to chargers). And to answer your question, IEC60950 (which I believe would be applicable) requires a Hi-pot test of 3000 VAC / 4000 VDC for 60 seconds. So while being a different test from the transient used by IEC61010, it is not that far off.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 16, 2017, 03:11:39 pm
You can name all the safety certificates you want (which I am all aware off).

Thank you for your permission, I was really worried I would not get it.

A very respected, smart and highly intelligent person in science and engineering with over 50 years of experience, ones told me the following (unfortunately I'm not allowed to share his name in public)

I can invent imaginary friends too, I think I had one when I was 3.

"People always say safety first. Which is very incorrect and even dangerous.
It is thinking first (just follow basic science and engineering), than safety and third is sometimes just random bad luck"

Your imaginary friend has a problem with grammar. Too bad you can't translate WTF he is saying.

In fact, it is even proven that blindly following safety protocols can even lead to potentially more dangerous situations.
You should teach people the how and why instead.

Right, knowledge prevents people from making mistakes, always.... Is this you saying this or your imaginary friend?

With me a lot of people in the field are getting extremely sick of all the ridiculous so called 'safety rules'.

Yes, safety rules only exist for those not as perfect in every way and every action as you are. I can understand why you wouldn't care as you will never and have never made an error in anything. Everyone in the past who has ever been injured or killed has been because they, and they alone, did not have the knowledge of a procedure.

You can write pages about how many years of experience you have and what kind of qualifications or certificates etc, but it all simply comes down to some general science knowledge.

Wow, sorry everyone, I should never have brought up experience and training. These must never have anything to do with reality again.

Because it simply doesn't make sense why nobody cares about batteries, while it doesn't cost much to kill someone very easily with a 9V battery!
I know companies/countries where someone isn't even allowed to handle a bloody standard knife anymore  |O :palm: :palm:
If people are to dumb to know what they are doing, they shouldn't be doing it in the first place.
In fact, in a lot of countries that's even how the law system work.

Really? How does someone know not to do something when they don't know not to do it? Certainly encouraging people to not do things they don't know sufficiently how to do properly is EXACTLY what I have been arguing. So you agree with me. You just said so. WTF are you on about then?

Which means that it's not important anymore if a product was 'unsafe', just by the fact that you were doing things you weren't qualified for cancels everything out.

 |O

Btw, with all the respect, but I don't know who brainwashed people that 'you need approved safety facilities' to test safety.
Than you simply have fallen in the big marketing trap.

Right, lets have people who don't know what they are doing or can't prove what they are doing is correct, let's have them do the testing. Wait, did you just say "If people are to dumb to know what they are doing, they shouldn't be doing it in the first place."  :palm:

You forget the reason WHY these facilities exist, with the one and only reason: cover themselves in court.
Nothing more, nothing less.

OK, now that is just totally bat shit tin foil hat time. Nothing more, wow......

That doesn't mean that other ways aren't safe.

But other methods that are unknown to be safe should not be the default, idiotic reasoning.....

(in fact I know many so called 'safety regulations' in some countries that are absolutely forbidden in others)
Second to that, if safety is so important, why is it SO difficult and SO expensive to get these tests done, of to even get the basic documents?
These things should be open to the public.

Yeah yeah, people drive on the other side of the road in some places too, idiotic reasoning....

All of this doesn't mean that there are people out there that make these type of meters, review a lot of meters or just have a very good understanding what potential dangerous there are and how to tackle them or are just smart people with enough knowledge/resources to find that out.
These meters and safety tests are not done by unknown hyper smart aliens.

And people make mistakes, don't know everything, and forget certain details. That is why we have repeatable tests for safety that are replicated  by different people who follow checklists. That is how human errors get caught.

So in fact, I would ENCOURAGE people to dig into this and share it to the public because in my opinion that's even your responsibility as an engineer/scientist.
And to add something extra for the people who have so "many experience in the field", maybe it would be better to help people out, explain it how it is done properly instead of kicking people shins.
If you can make the time and energy to rant, you can also use the same time and energy to be productive instead.
Talking about proving.......

Sorry everyone, I am being a non-productive world citizen by trying to educate. Forget all the rules everyone. I was wrong, past events, experience and the rules to save people from harm are all just smoke and mirrors and corporate lawyers. Follow the person who is tired of having to be safe. He must be right!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 16, 2017, 04:32:45 pm
To be clear, I am not bad mouthing this meter. For a bench electronics meter it seems to be a relatively good buy except for the current measurement limitations it seems to have. Except for the false CAT ratings it has I would be happy to recommend it from what I see.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 06:21:54 pm
So whenever I poke at line voltage I don't take any chances. The good expensive HRC fuses have one advantage - it's less likely to blow it because you know you'll pay another $15 for new one and you are extra careful.

The fuses are there so the meter meets its CAT ratings (ie. it doesn't matter where the range selector is) but you should never need them in practice.

In practice you should double-triple check that the switch is on 'voltage' before going anywhere near the DUT.

If you're ever in a situation where a bigger fuse would mean the difference between life/death then you're doing it very wrong.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 06:44:44 pm
Don't fool yourself into thinking that the meter is safer for the user.
BINGO!
Doesn't make much sense to me. If you make a meter safer, then it is in fact safer.

You're failing to understand the difference between "safety" and "robustness".

You can easily make a meter more robust by adding PTCs, etc.

Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.? No amount of PTCs will save you if there's a more fundamental problem somewhere else.

If you want a 'safe' meter then buy a meter with a suitable safety rating from a trusted manufacturer.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 16, 2017, 07:11:04 pm
Don't fool yourself into thinking that the meter is safer for the user.
BINGO!
Doesn't make much sense to me. If you make a meter safer, then it is in fact safer.

You're failing to understand the difference between "safety" and "robustness".

You can easily make a meter more robust by adding PTCs, etc.

Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.? No amount of PTCs will save you if there's a more fundamental problem somewhere else.

If you want a 'safe' meter then buy a meter with a suitable safety rating from a trusted manufacturer.

Not being experienced, how much is the meter case itself important when it comes to safety and user (not device) protection? Probe insulation as well, I would assume.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 16, 2017, 07:25:58 pm
Don't fool yourself into thinking that the meter is safer for the user.
BINGO!
Doesn't make much sense to me. If you make a meter safer, then it is in fact safer.

You're failing to understand the difference between "safety" and "robustness".

You can easily make a meter more robust by adding PTCs, etc.

Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.?
Yes. Why not?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 16, 2017, 07:58:34 pm
Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.?
Yes. Why not?

You are going to do your own PCB layout for this $20 meter, and then remove and resolder all components including the chip-on-board main IC?! Yeah, sure...  :palm:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 16, 2017, 08:11:40 pm
Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.?
Yes. Why not?

You are going to do your own PCB layout for this $20 meter, and then remove and resolder all components including the chip-on-board main IC?! Yeah, sure...  :palm:
No. Why would I do that? If a clearance is too small, a slot can be added, or a separator added. You make it sound like a multimeter is beyond the understanding of mortals.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 16, 2017, 08:27:45 pm
If a clearance is too small, a slot can be added, or a separator added. You make it sound like a multimeter is beyond the understanding of mortals.

No, I don't. I am merely implying that those slots are not added as an afterthought, but are planned as part of the layout process. It would be a very lucky coincidence if, in an existing compact multimeter layout, you find room for slots in all places where they are needed to meet the stated CAT ratings.

Well, mill away to your heart's content. You will only be wasting $20 and a few hours of your time...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 09:08:27 pm
Not being experienced, how much is the meter case itself important when it comes to safety and user (not device) protection?

Quite important. The 'explosion' is copper turning into gas inside the meter, along with a increase in volume. Fluke cases are designed to hold that in and release it slowly.

There's quite a few videos of exploding meters on youtube. I think joe's managed  burst a couple of cases, too.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 09:11:27 pm
Making it safer is a lot more difficult, eg. Are you really going to cut slots in the PCB  and/or improve the spacing between PCB traces, etc.?
Yes. Why not?

OK, go ahead. Let's hope there's nothing important on the other side of the board where you cut your slots.

Be sure to post test results.  :popcorn:

PS: Joe's actually done similar modifications to meters in his robustness thread.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 16, 2017, 09:32:05 pm
There is no reason to buy, or, even worse, to use this meter.
It is lying about its safety specs --> getting immediatly disqualified.
End of story.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 09:40:27 pm
There is no reason to buy, or, even worse, to use this meter.
It is lying about its safety specs --> getting immediatly disqualified.
End of story.

You're saying we might die if we measure a 1.5V battery with this meter?  :o

Thanks for the warning!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 16, 2017, 09:41:49 pm
There is no reason to buy, or, even worse, to use this meter.
It is lying about its safety specs --> getting immediatly disqualified.
End of story.

I don't think these categorical statements help anyone -- and they don't help your reputation on the forum either. There are obviously plenty of reasons for buying and using this multimeter, as witnessed by the thread above and also the main thread on this meter. And I am sure your post will not be the end of the story; to be witnessed by more posts below.

You are free to make the safety rating your personal top priority; but then please state it as such. For me (personally, again), having a compact backup meter with a very nice display and with low current/low voltage capability, at a very attractive price, makes this a worthwhile purchase. I will add a sticker to point out that it must not be used on mains voltages, and will be merry.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 16, 2017, 10:03:49 pm
There is a deeper reason for this categorial statement.
It is not a problem, if this thing is used by people, which are experienced, knowing, what they are doing and do know about the limitations of such a thing.
Fine.
But, because of the poor safety design of this thing, it is more likely, that it will fail than, let's say, a Brymen 869s.
And when it fails, it could be, that it'll cause more damage, injuries etc. than the Brymen. Or a Fluke 87V.
And all this for a $20 meter?
No way.
And even, if you are knowing what you are doing, what if somebody else grabs this meter and poking around a bit?
My experience taught me, that stickers, warnings etc. will be ignored. For obscure reasons.
I'm not talking about highly trained people like engineers in this respect. I have a nephew which is very curious about
the things I'm doing and I would never excuse myself, if he's grabbing such a meter to measure stuff and he will get injured or even worse because of such a crappy meter.
The main point is: you do not have it under control anytime, anywhere.  So, the safest thing is: there is no such meter around, therefore nobody can use it.

And yes, I am aware, that there is no such thing as 100% safety. But to me it makes a differences, if a thing will fail in 1% of the cases using it or in 0.001% of the cases using it. And how it will behave, if it is failing.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 10:18:02 pm
And all this for a $20 meter?
No way.

I have much less of a problem with this one than a $60 meter like the UT61E (for example). People buying a UT61E might think they're getting a decent meter - $60 is a lot of money.

Even worse was the $180 Uni-T bought by Dave. Even Dave thought he was getting a decent meter, but nooooo.

And even, if you are knowing what you are doing, what if somebody else grabs this meter and poking around a bit?
My experience taught me, that stickers, warnings etc. will be ignored. For obscure reasons.
I'm not talking about highly trained people like engineers in this respect. I have a nephew which is very curious about
the things I'm doing and I would never excuse myself, if he's grabbing such a meter to measure stuff and he will get injured or even worse because of such a crappy meter.
The main point is: you do not have it under control anytime, anywhere.  So, the safest thing is: there is no such meter around, therefore nobody can use it.

You're free to not buy one just like we should be free to accept the risks.

Or you could buy a gun safe for your meters.

Or ... you could try educating your nephew. When I do electronics classes I open up a DT830B and show them the blank space where the fuse was supposed to be, a $15 meter and show them the tiny fuses, and then a Fluke. The message usually sinks in.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 10:18:40 pm
There is a deeper reason for this categorial statement.
It is not a problem, if this thing is used by people, which are experienced, knowing, what they are doing and do know about the limitations of such a thing.
Fine.
But, because of the poor safety design of this thing, it is more likely, that it will fail than, let's say, a Brymen 869s.
And when it fails, it could be, that it'll cause more damage, injuries etc. than the Brymen. Or a Fluke 87V.
And all this for a $20 meter?
No way.
And even, if you are knowing what you are doing, what if somebody else grabs this meter and poking around a bit?
My experience taught me, that stickers, warnings etc. will be ignored. For obscure reasons.
I'm not talking about highly trained people like engineers in this respect. I have a nephew which is very curious about
the things I'm doing and I would never excuse myself, if he's grabbing such a meter to measure stuff and he will get injured or even worse because of such a crappy meter.
The main point is: you do not have it under control anytime, anywhere.  So, the safest thing is: there is no such meter around, therefore nobody can use it.

And yes, I am aware, that there is no such thing as 100% safety. But to me it makes a differences, if a thing will fail in 1% of the cases using it or in 0.001% of the cases using it. And how it will behave, if it is failing.

I do agree with you. Such cheap meters are quite appealing to beginners and I remember myself as a beginner using shit meters (I didn't know there were shit). When I started working on mains with power supplys etc I used those meters too.
Now I woudn't but with no other meter around or at the other side of the room, who would measure mains with it ? I strongly believe that say the good meter is across the room, even with experience youre are likely to use the cheap one you have at hands.
Now think of a newbie using such a meter not knowing the risks... I would never reccomend such a meter to a newbie, I couldn't.
Plus stickers and so on don't do shit.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 16, 2017, 10:22:28 pm
Jep. In my humble opinion safety is not alone about personal safety. It is also dedicated to circumstances and other people.
That  is one of the things I've learned since I was 12 years old and joined the voluntary fire brigade in my home village.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 16, 2017, 10:29:12 pm
The safety paranoia and scaremongering is getting a bit too much.. Is this what Fluke propaganda does?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 10:32:48 pm
The safety paranoia and scaremongering is getting a bit too much.. Is this what Fluke propaganda does?

Propaganda of every safe meter.
Everybody is free to buy what they want, just don't put others in danger. I'm just giving my opinion here, agree or don't.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 16, 2017, 10:43:42 pm
Even worse was the $180 Uni-T bought by Dave. Even Dave thought he was getting a decent meter, but nooooo.

I try to avoid UNI-T meters and do not recommend them at all.

Quote
You're free to not buy one just like we should be free to accept the risks.

Yes, everyone has to decide that for himself.

Quote
Or you could buy a gun safe for your meters.

*trolling ignored*

Quote
Or ... you could try educating your nephew. When I do electronics classes I open up a DT830B and show them the blank space where the fuse was supposed to be, a $15 meter and show them the tiny fuses, and then a Fluke. The message usually sinks in.

That is exactly, what I'm doing. Educate and explain things to him. But, since he is 8 years old, I am aware, that he will not always follow the things he was taught. And for this it is better, when there is no such thing around.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 16, 2017, 10:46:53 pm
I doubt this meter would kill anybody on CAT II mains with any range selection.

(Anybody out there willing to sacrifice a fuse to see how eventful it would be?)

Besides, the CAT (ahem) is already out of the bag. This meter doesn't make anybody less safe in a world where Harbour Freight is giving away much worse meters for free.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 16, 2017, 10:47:30 pm
Seems to be  a lot of talk about modding this meter to improve it's safety.
I don't see the point, in fact I think it's a pretty dumb idea and a waste of time.
The meter is what it is, if you buy it just live with its limitations.
If you want a safe meter for electrical work, pay double (still under $50!) and get a Fluke 101.

It's also interesting to see so much talk on Youtube comments about how supposedly spectacular this meter is and why I didn't give it thumbs up. They seem to think I've uncovered the ultimate multimeter  ::)
Fact is it's missing major current ranges, doesn't have a REL function, has tiny PITA fuses, is obviously not a meter designed for electrical work, has quite ordinary build quality (some questionable soldering in fact), and who knows what variability in manufacturing and calibration over time.
Sure it's great for compact cheapie $25 meter, but it's hardly some utopia. But people seem to be going nuts over it for some reason.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 16, 2017, 10:54:43 pm
Seems to be  a lot of talk about modding this meter to improve it's safety.
I don't see the point, in fact I think it's a pretty dumb idea and a waste of time.


You can read a book on brain surgery, and convince yourself that in your couple of hours of reading the book. You know almost as much as real brain surgeons do, after their 20 or 30 years experience of performing thousands of operations.

Please DON'T go and operate on someone, in your mistaken belief that it will be SAFE.

tl;dr
Huge amounts of time and resources can be spent, making things safe. It is so easy for an armchair expert, to believe that they can do it, for a millionth of the cost, and a thousandth of the time it takes.
99.999999% of the time, they are wrong.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 16, 2017, 10:56:07 pm
I think it is the fact that the resolution goes down to values usually limited to bench DMMs. Some people might mistake this for accuracy (you compared it favorably to the Keysight bench DMM at low values). How many other handhelds go down to 1 µV / 10 nA / 10 mOhm? Should excite a low current nut like Dave :P. But definitely very niche.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 16, 2017, 10:56:32 pm
If you want a safe meter for electrical work, pay double (still under $50!) and get a Fluke 101.

I've read here in the forum a lot of recommendations of this Fluke 101.
I had a look at ebay and found this:
http://www.ebay.com/itm/351230522178 (http://www.ebay.com/itm/351230522178)
(https://i.ebayimg.com/00/s/NjAwWDYwMA==/z/PJUAAOSwTA9X2RXr/$_58.JPG)

These aren't real Fluke's, are they?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 16, 2017, 10:59:59 pm
If you want a safe meter for electrical work, pay double (still under $50!) and get a Fluke 101.

I've read here in the forum a lot of recommendations of this Fluke 101.
I had a look at ebay and found this:
http://www.ebay.com/itm/351230522178 (http://www.ebay.com/itm/351230522178)
(https://i.ebayimg.com/00/s/NjAwWDYwMA==/z/PJUAAOSwTA9X2RXr/$_58.JPG)

These aren't real Fluke's, are they?

Those go for about $38 on Ali. I don't know what they are exactly. Fluke for the Chinese market?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 11:01:10 pm
If you want a safe meter for electrical work, pay double (still under $50!) and get a Fluke 101.

I've read here in the forum a lot of recommendations of this Fluke 101.
I had a look at ebay and found this:
http://www.ebay.com/itm/351230522178 (http://www.ebay.com/itm/351230522178)
(https://i.ebayimg.com/00/s/NjAwWDYwMA==/z/PJUAAOSwTA9X2RXr/$_58.JPG)

These aren't real Fluke's, are they?
They actually are, but made for the chinese market only. They are lower quality and have only 1 year of waranty inside China. But still very good. I own one a Fluke 101.

Edit: Lower quality compared to those made in 'Murica, like the Fluke 177 for example.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 16, 2017, 11:08:10 pm
If people want a safe meter for electrical work, the Fluke 101 is $40 including delivery on Aliexpress!
UL certified and guaranteed consistent Fluke quality.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 16, 2017, 11:12:16 pm
Jep. In my humble opinion safety is not alone about personal safety. It is also dedicated to circumstances and other people.
That  is one of the things I've learned since I was 12 years old and joined the voluntary fire brigade in my home village.
If you were buying this meter for use by others or for use in a company, it would make sense to grind off the AN8008's suspect safety ratings and engrave "50V DC/AC Maximum".

For professional use, I would be getting something like a Fluke anyway. I think most people here are getting this meter for personal use and probably for low voltage use.

Just remember that the safest multimeter is not safe. I would not like getting stabbed by a multimeter probe, particularly by one of those really sharp Fluke ones. I wouldn't like being hit on the head by one knocked of the roof of a skyscraper. On the other hand, I would feel extremely safe with an AN8008 at 1000V if it was behind a blast shield.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tautech on July 16, 2017, 11:17:04 pm
Flukes that I've sourced from China have ONLY English externally on them. Under the yellow holster on the back of the meter are some Chinese characters that specify ratings.
Any that have Chinese on the face I'd be suspicious of.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 16, 2017, 11:19:55 pm
Do us all a favor and get one for teardown, $38 shipping included Fluke 101. https://www.aliexpress.com/item/FLUKE-101-portable-handheld-digital-multimeter-F101/32791856013.html (https://www.aliexpress.com/item/FLUKE-101-portable-handheld-digital-multimeter-F101/32791856013.html)

And side-by-side comparison with the US made logo 101.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 16, 2017, 11:35:05 pm
I bought mine for 50€ delivered from a Alikexpress seller that has/had stock in Germany.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Muttley Snickers on July 17, 2017, 12:02:52 am
I think most of us here would agree that unfortunately stupidity seems to trump safety every day of the week, reminding people of this won't do them any harm. This recently posted video below is a prime example of how a multimeter should not be used or tested under any circumstance, it is dangerous and serves no useful purpose to anyone, I believe the meter is a rebadged CEM of all things, madness. 

Bowls are for goldfish, or salads.   :o ::)

http://www.youtube.com/watch?v=gSjUe8_0_W0 (http://www.youtube.com/watch?v=gSjUe8_0_W0)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 12:07:08 am
What's wrong with that? What if your basement is flooded and you still want to finish your project!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 17, 2017, 12:15:07 am
Do us all a favor and get one for teardown, $38 shipping included Fluke 101. https://www.aliexpress.com/item/FLUKE-101-portable-handheld-digital-multimeter-F101/32791856013.html (https://www.aliexpress.com/item/FLUKE-101-portable-handheld-digital-multimeter-F101/32791856013.html)
And side-by-side comparison with the US made 101.

When has there ever been a US made 101? or any of those low end Chinese market Flukes?
Fluke's experiment with making meters in China started with the (infamous) Fluke 19 maybe 15 years ago now?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 17, 2017, 12:19:06 am
These aren't real Fluke's, are they?

Yes, they are real Flukes, designed for the Chinese market primarily.
The first one they ever did was the Fluke 19, and it was sold in Asia/Pacific only. Dick Smith used to sell them here in Oz.
AFAIK there has never been a rip-off clone Fluke on the market anywhere.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 12:22:04 am
You are of course correct - they are made in China, what I meant to differentiate was the Fluke 101 with the English logo from the one with the Chinese logo. First time I've seen the Chinese logo on a 101, or have these been common too?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 17, 2017, 12:43:48 am
You are of course correct - they are made in China, what I meant to differentiate was the Fluke 101 with the English logo from the one with the Chinese logo. First time I've seen the Chinese logo on a 101, or have these been common too?

The one in the picture, with Chinese writing, appears to be a FAKE to me. I.e. NOT a real Fluke.

I am aware that there are genuine, Chinese manufactured Fluke 101's.

If you compare that photograph, with a real Fluke 101. You can tell that it is apparently a fake, because there are one or more mistakes, in the fake one. E.g. Look carefully at the "HOLD" button. The real one has perfectly centered and correct text, but the apparent fake one has the "HOLD" font towards the top of the button, and looks different.
The seller has at least two of the people they sold them to, complaining, with at least one complaint seeming to imply it is a fake one as well.

But I'm not an expert on possible Fluke fakes, and have little information to go on. So I could be wrong.

I took the following as a genuine example of a real (non-fake) one:
(https://images-na.ssl-images-amazon.com/images/I/71AuWptHNeL._SY606_.jpg)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 01:00:01 am
It's not exactly the same angle, but here is a little animated gif:
(http://i.imgur.com/6p7a0MU.gif)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 01:08:09 am
Those Fluke 101s with the Chinese brand name on the front panel have been around for a while. See this video from October 2016, for example. (No teardown, unfortunately.)

http://www.youtube.com/watch?v=Q_xp6tRwnI4 (http://www.youtube.com/watch?v=Q_xp6tRwnI4)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 17, 2017, 01:27:30 am
Those Fluke 101s with the Chinese brand name on the front panel have been around for a while. See this video from October 2016, for example. (No teardown, unfortunately.)

I seem to be wrong as regards it being a fake, and it may well be genuine. Sorry for any confusion.

I think Fluke should have kept their trademarked "Fluke" symbol/text, and added Chinese text if they want. But to miss out on the English "Fluke" text, I think is a mistake on Flukes part.

I presume they did it for business reasons, to minimize sales to the West, of the cheaper Chinese manufactured Flukes and/or to keep the Chinese happy.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 01:35:01 am
Sure it's great for compact cheapie $25 meter, but it's hardly some utopia. But people seem to be going nuts over it for some reason.

People mainly see the price.

Also: There's enough positive things in the video that all the negatives are being filtered out (or at least, mentally justified).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 01:37:11 am
Jep. In my humble opinion safety is not alone about personal safety. It is also dedicated to circumstances and other people.
That  is one of the things I've learned since I was 12 years old and joined the voluntary fire brigade in my home village.
If you were buying this meter for use by others or for use in a company, it would make sense to grind off the AN8008's suspect safety ratings and engrave "50V DC/AC Maximum".

Are you sure that 50V is 100% safe under all conditions? Have you tested that?

We wouldn't want to take any chances...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 01:38:05 am
People mainly see the price.
Also: There's enough positive things in the video that all the negatives are being filtered out (or at least, mentally justified).

And, let's face it, it looks cute.  ;)
Neat form factor and industrial design, very nice display and backlight. Worked for me; I have one on order...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 01:40:56 am
These aren't real Fluke's, are they?

Yes, they are real Flukes, designed for the Chinese market primarily.
The first one they ever did was the Fluke 19, and it was sold in Asia/Pacific only. Dick Smith used to sell them here in Oz.
AFAIK there has never been a rip-off clone Fluke on the market anywhere.

Fluke has a lot of policemen watching us.

I'm sure we can all remember when they confiscated a whole shipment of Sparkfun meters because they were too yellow.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: FrankBuss on July 17, 2017, 02:39:02 am
Nice multimeter. The microvolt resolution was the reason I just bought it from eBay, for EUR 17.99, free shipping. Sometimes this is just the shipping fee if you buy other products- Will open it when it arrives to fix the jack soldering :D
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 17, 2017, 02:44:15 am
People make a lot of noise about false CAT-ratings. Why don't the same people make a lot of noise about what really matters when it comes to electrical safety?

Most countries around the world have a lot of legal regulations about education and long-time experience specifying what kind of work you are allowed to do on almost ANY kind of electrical equipment or wiring.

My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

So, why don't you spend your time telling beginners to stay away from what they are not allowed to do instead of all the scaremongering?

Wrong CAT-ratings are among the least thing a beginner should worry about when it comes to safety.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 02:46:58 am
I bought mine for 50€ delivered from a Alikexpress seller that has/had stock in Germany.

Good pictures.  I've never had mine apart.  Mine is marked "Fluke" in English as well. 

After testing so many meters, I really appreciate Fluke using that large PTC.  Some companies will put these little piss ant PTCs.  They will typically arc over, damaging the outside layer.  Once they arc, they no longer offer a high impedance path.  Normally when a company skimps like this, they don't have enough protection to save the parts downstream and the meters are normally non-repairable.   One of the first things I did with the UNI-T UT61E, based on my experience was to swap out the piss ant PTCs for some larger parts. 

Then look at how well thought out the layout is on the 101.  I've seen a lot of crap layouts.  Normally it's where they will have loops and when you hit the meter with a transient, there can be enough drops in some of the traces that can damage the meter.  The $300 POS UNI-T UT181A is a great example of this.   In pure UNI-T style, the grill starter of all things killed it on the first hit. 

Sad thing about UNI-T is I am not aware of ANY of their products being certified for safety or EMC.  If they went through this process, they may actually learn how to design better products.   

The solid performer's during my testing from an electronic design standpoint were the Fluke 101/107/115, Brymen BM235s and Hioki DT4252.  Even the Gossen Metrawatt M248B with it's ability to change relay states from the magnetic hanger causing it to read low voltage levels, is still a solid player for robustness.  These meters don't have some supper secret techniques that make them so robust, nor did the companies spend a lot of money on the front ends. 

Once we get to about 4KV, there are very few meter's that survive and really there is little excuse for it IMO.  Of the ones that are damaged,  some designs have enough protection to prevent the IC/s from being damaged.  In these cases, it can be a matter of just changing a few common parts to bring them back to life.  Of the ones I have looked at, this still makes up a very low percentage and most become recycled waste. 

We know Dave's stance on the 121GW from his post:   

I think it's important to also understand Joe's tests in context.
The Fluke 87V, the most trusted meter on the market, fails every single one of Joe's tests. According to Joe's tests it's one of the worst meters on the market. Yet I doubt there is a single 87V owner ever who has seen their meter die due to any ESD or pulse overload etc.

I agree.. most of the tests are a worst case scenarios (black swan events). 87v is a standard when it comes to rugged meters but has failed many of Joes tests. In fact Fluke 101  :) has passed more tests then any of the more expensive meters.

For me it's simply a matter of has a meter passed independent safety testing (UL, ETL etc). If so then it's good enough to recommend and use it on anything it's rated for.
Sure, if a meter is failing ESD testing or something that could potentially be common place, then that may be a cause for concern, but even the Fluke 87V has shown no sign of doing that in practice for the 13 years it's been released as the V series, apart from Joe's test.

Which I agree from a safety standpoint but it's also why I try to inform people to look for meters that not only are certified for the 61010 but also for the latest EMC 61326 standard as well.  Meters that have passed the EMC standard have typically done well in my tests.  The TPI 194II, even though it was UL listed (for 61010-1) never mentions the EMC standard and sadly failed what I consider a very basic test.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 02:54:42 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 03:02:22 am
Jep. In my humble opinion safety is not alone about personal safety. It is also dedicated to circumstances and other people.
That  is one of the things I've learned since I was 12 years old and joined the voluntary fire brigade in my home village.
If you were buying this meter for use by others or for use in a company, it would make sense to grind off the AN8008's suspect safety ratings and engrave "50V DC/AC Maximum".

Are you sure that 50V is 100% safe under all conditions? Have you tested that?

We wouldn't want to take any chances...

It would be nice if some of the large companies who are involved with this site, rather than having sales/marketing would have their compliance people involved.   Like that would ever happen.   Anyway, I believe the low voltage directive makes a distinction at 50VAC for safety.  Maybe OP is aware of this and why they specifically used this number.  :-// 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 17, 2017, 03:02:54 am
There is no fuse in the Fluke 101. I doesn't measure current. For that you need the Fluke 106 that doesn't heave diode measurment. Only the Fluke 107 has them all. Of course it's the most expensive. The are trying to upsell you really hard here.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 03:05:57 am
There is no fuse in the Fluke 101. I doesn't measure current. For that you need the Fluke 106 that doesn't heave diode measurment. Only the Fluke 107 has them all. Of course it's the most expensive. The are trying to upsell you really hard here.

Right, I i didn't think about that part. Thanks!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 03:18:02 am
A lot a cheap meters are not very robust, electrically or mechanically, I'll grant you that. It can be easy kill the meter, but they are still far from hurting the user. What would it even take to hurt the user through the case of a meter?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 03:19:26 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.

The 101 can't directly read current.  It's one of the reasons I like the meter for beginners. One less thing to get you into trouble.  Of course you may still be able to use a shunt or an amplified shunt with it to measure current. 

The 107 can read current and is still fairly small but comes with a price.  Like its little brother the 101,  its also very robust.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 17, 2017, 03:24:03 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.

The 101 can't directly read current.  It's one of the reasons I like the meter for beginners. One less thing to get you into trouble.  Of course you may still be able to use a shunt or an amplified shunt with it to measure current. 

The 107 can read current and is still fairly small but comes with a price.  Like its little brother the 101,  its also very robust.

I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 03:41:39 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.

The 101 can't directly read current.  It's one of the reasons I like the meter for beginners. One less thing to get you into trouble.  Of course you may still be able to use a shunt or an amplified shunt with it to measure current. 

The 107 can read current and is still fairly small but comes with a price.  Like its little brother the 101,  its also very robust.

I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.

Regarding making shunts, is it as simple as getting a high wattage, high accuracy resistor?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 17, 2017, 03:43:34 am
A lot a cheap meters are not very robust, electrically or mechanically, I'll grant you that. It can be easy kill the meter, but they are still far from hurting the user. What would it even take to hurt the user through the case of a meter?

Found this video, please have a look at 5:30 onwards:
http://www.youtube.com/watch?v=OEoazQ1zuUM (http://www.youtube.com/watch?v=OEoazQ1zuUM)

Part 2 of this video:
http://www.youtube.com/watch?v=H3kraHn7Fs8 (http://www.youtube.com/watch?v=H3kraHn7Fs8)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 17, 2017, 03:45:25 am
I'm getting myself some 1Ohm 2W metal film resistors and put ten of them in paralell. 20W sould be enough and it also should be reasonably accurate. Buying a adequate shunt, could be quite expensive I think.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on July 17, 2017, 03:54:38 am
@Dave : if a chinese seller sees your adress, i,m sure they send you the best of whole china!
Anyways after looking your movie i also want one until i see a good bench model, thanks for saving me 830 euro.
I hope Aneng also releases a bench model sooner or later with nice specs, i dont like the batteries.

Hope we all get a good one like you!,only i can not verify, if another person also can test the accuracy ?, would be nice.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 03:58:01 am
A very spectacular show to sell Fluke meters.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 17, 2017, 04:17:30 am
A very spectacular show to sell Fluke meters.

Yep. Glad to see, that you are impressed.  :-+
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 04:17:58 am
A lot a cheap meters are not very robust, electrically or mechanically, I'll grant you that. It can be easy kill the meter, but they are still far from hurting the user. What would it even take to hurt the user through the case of a meter?

It's not a simple question to answer because there are so many variables.... 

I think this is why we have standards for safety.   I can tell you that I have taken a few meters that would breakdown on my low energy transient generator and have ran them with a higher energy generator.  In these cases I have seen the leads come apart, sparks and such emit from the cases and I think a knob flew off once.  This testing is not even close to the levels that the IEC standard's would call for.  If you took 100 free HF meters, put them all into current mode, then without gloves, attach them across the 220 feed going into your house, one after then next, would you ever get hurt?  You would have to be pretty stupid to try it!

I find it interesting how many people continue to write me about how my testing far exceeds what the meters are designed to and how pointless it is.  That last one Cliff erased was really far fetched with the person was telling me how I was discharging these capacitors directly across the meters.  How stupid do you have to be to make statements like this?    Of course, you check their YT page and it's full of game videos or how to repair your car, then you understand. 

I have a few friends who are aware of the testing I have been doing with these meters.  They are not all EEs or have electrical backgrounds.  One friend of mine and I went to visit another person and my friend tells them about this testing I was doing.   This person gets very interested and asks why would I ever run these sort of tests.  I explain in basic terms assuming they know very little about electricity. It turns out this person was a retired electrician and actually worked for the power plant that I just visited.  There are very strict procedures that everyone follows, including the electricians.   One day he and another person need to go into one of the switch rooms to take some measurements.  Two people are always mandatory. They also have people in charge of shutting down gear and such.  It's never one person involved like Lightages mentions.   Anyway, they tell me how they never felt all the PPE was needed, until this day.  They have all their gear on.  He is holding the meter and the other person in front of him is holding the probes.  These are a few feet long.  He attaches the probes and next thing that happens if the meter cuts loose in this guys hands.   This changed their view on safety.  This is a big deal at a power plant and they (not the electricians involved) had to do an investigation to what happened and come up with corrective actions.  These people just don't get hired off the street or have a background in home wiring or IT. 

One of the people I was with had a spouse who was responsible for shutting down sections of the plant for other people to do their work.  I understand the stress of knowing if they made a mistake could cost someone their live drove them to find new employment.   Another person who was with us was explaining all of the testing and training that group had to continually go through.   Sounds like a very high stress job.   I guess they lost an electrician who entered an area that was to have been shut down.  Something was missed. 

I've been at places with some fairly large equipment (high energy).  Liquid cooled cables and such.   Nothing like this setup.    Like others have said, I doubt you are going to be allowed to take your UNI-T into work and use it on a CAT III or IV area in most cases. 

Sorry for the long post. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 04:23:51 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.

The 101 can't directly read current.  It's one of the reasons I like the meter for beginners. One less thing to get you into trouble.  Of course you may still be able to use a shunt or an amplified shunt with it to measure current. 

The 107 can read current and is still fairly small but comes with a price.  Like its little brother the 101,  its also very robust.

I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.

Regarding making shunts, is it as simple as getting a high wattage, high accuracy resistor?

I'm getting myself some 1Ohm 2W metal film resistors and put ten of them in paralell. 20W sould be enough and it also should be reasonably accurate. Buying a adequate shunt, could be quite expensive I think.

I have a playlist that includes the videos  I have made where I have played around with shunts to measure current.  Personally, I will use an external shunt more often than the meters internal current measurement. 

http://www.youtube.com/playlist?list=PLZSS2ajxhiQDhlXQCyoNSDmUjb6lAqC8z (http://www.youtube.com/playlist?list=PLZSS2ajxhiQDhlXQCyoNSDmUjb6lAqC8z)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 04:31:41 am
I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.

I'm sure that will be much safer than the flimsy AN8008...  :P
Don' forget the HRC fuse, blast-proof enclosure etc.!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Rbastler on July 17, 2017, 05:12:19 am
I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.

I'm sure that will be much safer than the flimsy AN8008...  :P
Don' forget the HRC fuse, blast-proof enclosure etc.!

Oh, I'm sure it will be.  https://www.pollin.de/p/alu-gehaeuse-raychem-rpg-aluein-98x64x34-mm-460166 (https://www.pollin.de/p/alu-gehaeuse-raychem-rpg-aluein-98x64x34-mm-460166)
Try to blast this one...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 05:19:05 am
Appreciate your input joe, all read!  ;) Big fan of your robustness testing videos.


Yet more suggestions for meters to test in the future: Chauvin Arnoux MTX 32xx or any of the clamshell style ones (another major European manufacturer akin to Gossen)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 05:30:22 am
https://www.pollin.de/p/alu-gehaeuse-raychem-rpg-aluein-98x64x34-mm-460166 (https://www.pollin.de/p/alu-gehaeuse-raychem-rpg-aluein-98x64x34-mm-460166)
Try to blast this one...

Looks conductive though. What about those 1000 Volts?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 05:30:31 am
I'm thinking of building a shunt adapter for the Fluke 101. Basically some test leads cut open and a shunt soldered in place.

I'm sure that will be much safer than the flimsy AN8008...  :P
Don' forget the HRC fuse, blast-proof enclosure etc.!

I can't think of a time I have ever used a hand held meter to look at current in a CAT III environment, outside of a clamp.  I have heard of people attaching a meter with the leads connected to the current inputs across the AC line by mistake.  Do this in a CAT II, chances are good you may only pop a fuse of trip a breaker.  CAT III and up is where the HRC fuses really come into play.   

From 61010-2-033:2012

MEASUREMENT CATEGORY   Short-circuit current (typical)   Location in the building installation
                                                          kA a
II                                            < 10                                 Circuits connected to MAINS socket outlets,
                                                                                       and similar points in the MAINS installation
III                                           < 50                                 MAINS distribution parts of the building
IV                                         >> 50                                 Source of the MAINS installation in the building

a The short-circuit current is calculated for a 1 000 V line-to-neutral voltage and the
minimum loop impedance. The values of loop impedances (installation impedances) do
not take into account the resistance of the probe assemblies and impedances internal
to the measuring equipment. These short-circuit currents vary, depending on the
characteristics of the installation.

In the case of the 101, there is no current input.  Chances of someone accidently leaving their external shunt attached and going across the line, well I won't say it can't happen but I would say chances are slim to do this unintentionally.  We do have people who think it's fine to connect their meter to the output of a MOT and wonder why it dies then blame the mfg.
 
Like Dave's uCurrent Gold most of the time I would use a shunt, it's unfused and out in the open.  I use them in circuits of 300A and less at 50V and under.   For me, the risk is fairly low. 

How many of you have hooked Dave's uCurrent Gold directly across the AC line to measure current?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 17, 2017, 05:46:11 am
People make a lot of noise about false CAT-ratings. Why don't the same people make a lot of noise about what really matters when it comes to electrical safety?

Most countries around the world have a lot of legal regulations about education and long-time experience specifying what kind of work you are allowed to do on almost ANY kind of electrical equipment or wiring.

My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

So, why don't you spend your time telling beginners to stay away from what they are not allowed to do instead of all the scaremongering?

Wrong CAT-ratings are among the least thing a beginner should worry about when it comes to safety.

More idiotic reasoning. :bullshit:

Beginners need to learn, and learning entails mistakes. A newbie should be able to buy a meter that has a CAT rating that matches its capabilities. A newbie is relying on his limited knowledge to select a meter that will help protect him against his mistakes.

Who needs standards of safety?

Would you feed your baby a jar of baby food that was labelled with false safety ratings?

Would you get into a car where the seat belts were only inspected by "Inspector #22" and had little gold stickers to prove their safety?

Would you go to a doctor who had the approval for his knowledge and care by someone on a forum?

Would you recommend that your child get in that "taxi" that only has a piece of paper taped to the window that says "Taxi"?

Would you, if you like to, do a bungie jump with someone who was parked at the side of the road in their old van on a bridge and was offering "Cheap Bungie Jumps Only $10"?

Would you tell newbies to buy whatever meter they want, marked with false safety markings or not, but stay away from things they don't know about?

Oh wait, you are saying that. You are telling people who don't know what is safe or not to ignore false safety ratings.......
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 05:51:29 am
I have heard of people attaching a meter with the leads connected to the current inputs across the AC line by mistake.  Do this in a CAT II, chances are good you may only pop a fuse of trip a breaker.  CAT III and up is where the HRC fuses really come into play.   

I agree. Operator error, while intending to measure voltage in a CAT III circuit, might be one of the more common scenarios where HRC fuses are beneficial. (If there were no relevant scenarios at all, why are we complaining so much about meters which don't have proper HRC fuses while claiming CAT III?)

My point was -- why complain about the AN8008 and its tiny fuses, and then rig up "some test leads cut open and a shunt soldered in place" to measure current with your Fluke 101 ? That's what Rbastler initially announced he wanted to build, and what I was commenting on. Seems he has raised the bar in the meantime; and I have no doubt that a shunt can be built properly. Whether that gives you the most economic/compact/convenient solution, compared to buying e.g. a Brymen BM235 in the first place, is another matter...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 06:20:54 am
My point was -- why complain about the AN8008 and its tiny fuses, and then rig up "some test leads cut open and a shunt soldered in place" to measure current with your Fluke 101 ? That's what Rbastler initially announced he wanted to build, and what I was commenting on. Seems he has raised the bar in the meantime; and I have no doubt that a shunt can be built properly. Whether that gives you the most economic/compact/convenient solution, compared to buying e.g. a Brymen BM235 in the first place, is another matter...

IMO, any meter, not just the AN8008, with a built-in shunt you are prone to making a mistake with it.   The 101 with an external shunt I would again say chances are slim to make that same mistake.   As you mention the BM235 which is certified, so even if you do intentionally do some idiot move with the current inputs or just make a mistake, assuming you were not stupid enough to jump the fuse like some member's here, you should fair better than the AN8008 in the same case.  That's a guess on my part and if it were me, I can tell you which meter between the two I would choose hands down!   I would still say, the 101 without the current input would be a better setup.   

When I was looking at what Gossen meter to run, it seems they offered some without the current input as well.  I almost went that route but actually had hopes that the Ultra would be a replacement for my Brymen.  Not even in the same playing field.  It did cost more so I guess I could brag about owning a Gossen meter now.  :-DD  Sadly, I never did hear anything more from them. 

The old Fluke 97 scopemeters I picked up also don't have shunts.   When I leave the hole and need to look at the mains, my tool of choice is that HIOKI I showed.  Again, it has no internal shunt.   Like the Gossen I looked at and my Fluke 97, you use clamps with it.   
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 06:31:29 am
Sorry to ask guys and I'm sure it must be obvious, but where is the fuse on the Fluke 101? I did notice the PTCs, but didn't see a glass or ceramic fuse in the images.

There isn't one, it doesn't have a current range.  :)

(which is how they make such a safe meter in such a small case)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 06:37:44 am
Regarding making shunts, is it as simple as getting a high wattage, high accuracy resistor?

Yes.

eg.

http://www.ebay.com/itm/152249838861 (http://www.ebay.com/itm/152249838861)

http://www.ebay.com/itm/262880450911 (http://www.ebay.com/itm/262880450911)


Edit: It's a good idea to add a fuse as well :-)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 06:44:57 am
IMO, any meter, not just the AN8008, with a built-in shunt you are prone to making a mistake with it.   The 101 with an external shunt I would again say chances are slim to make that same mistake.   

And if you could get a meter which cannot measure voltage either, it would be even safer! ;)

Quote
As you mention the BM235 which is certified, so even if you do intentionally do some idiot move with the current inputs or just make a mistake, assuming you were not stupid enough to jump the fuse like some member's here, you should fair better than the AN8008 in the same case.  That's a guess on my part and if it were me, I can tell you which meter between the two I would choose hands down!   I would still say, the 101 without the current input would be a better setup.   

I have a BM257s, which I use as my "universal" meter. And I certainly intend to continue using that for anything mains-related. But the AN8008 is a neat addition for tinkering and travel use. For these purposes, I like the all-in-one functionality and the low-current and low-voltage ranges, which actually go beyond the BM257's capabilities.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 17, 2017, 06:50:49 am
There is no reason to buy, or, even worse, to use this meter.
It is lying about its safety specs --> getting immediatly disqualified.
End of story.


It's also not a cheap meter once you open up and re-solder and check all those solder starved joints,
what's ONE hour of your tech time worth?  assuming all the 'price point selected' components can survive another high temperature ordeal

I would not trust those ridiculous midget fuses to blow when required,
or even assume they have sand in them, much less an extinguishing type,
and highly doubt their shortass arc flash distance show stopping ability 

At least with cheapo glass fuses WYSIWYG,
and any concerned owner has the option to replace with a decent rated ceramic fuse in a STANDARD  M205, 3AG or HRC format,
rather than those standup comedy midget fuses   :-DD 

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 07:01:27 am
IMO, any meter, not just the AN8008, with a built-in shunt you are prone to making a mistake with it.   The 101 with an external shunt I would again say chances are slim to make that same mistake.   

And if you could get a meter which cannot measure voltage either, it would be even safer! ;)

Quote
As you mention the BM235 which is certified, so even if you do intentionally do some idiot move with the current inputs or just make a mistake, assuming you were not stupid enough to jump the fuse like some member's here, you should fair better than the AN8008 in the same case.  That's a guess on my part and if it were me, I can tell you which meter between the two I would choose hands down!   I would still say, the 101 without the current input would be a better setup.   

I have a BM257s, which I use as my "universal" meter. And I certainly intend to continue using that for anything mains-related. But the AN8008 is a neat addition for tinkering and travel use. For these purposes, I like the all-in-one functionality and the low-current and low-voltage ranges, which actually go beyond the BM257's capabilities.

I've never looked at the 257s.  For GP use I still like the 869s over any of them I have looked at.  Anymore, if I needed something with better specs for the home lab, I would just get a used name brand bench meter.   Seems like a better investment than a cheap meter.   

Yes, if you could remove the voltage input it would make the meter even safer.  I've looked at a meter like this.

https://youtu.be/7DL4OIKTnGE?t=192
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 07:19:21 am
Yes, if you could remove the voltage input it would make the meter even safer.  I've looked at a meter like this.
https://youtu.be/7DL4OIKTnGE?t=192

;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 17, 2017, 07:40:07 am
People make a lot of noise about false CAT-ratings. Why don't the same people make a lot of noise about what really matters when it comes to electrical safety?

Most countries around the world have a lot of legal regulations about education and long-time experience specifying what kind of work you are allowed to do on almost ANY kind of electrical equipment or wiring.

My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

So, why don't you spend your time telling beginners to stay away from what they are not allowed to do instead of all the scaremongering?

Wrong CAT-ratings are among the least thing a beginner should worry about when it comes to safety.

More idiotic reasoning. :bullshit:

Beginners need to learn, and learning entails mistakes. A newbie should be able to buy a meter that has a CAT rating that matches its capabilities. A newbie is relying on his limited knowledge to select a meter that will help protect him against his mistakes.

Who needs standards of safety?

Would you feed your baby a jar of baby food that was labelled with false safety ratings?

Would you get into a car where the seat belts were only inspected by "Inspector #22" and had little gold stickers to prove their safety?

Would you go to a doctor who had the approval for his knowledge and care by someone on a forum?

Would you recommend that your child get in that "taxi" that only has a piece of paper taped to the window that says "Taxi"?

Would you, if you like to, do a bungie jump with someone who was parked at the side of the road in their old van on a bridge and was offering "Cheap Bungie Jumps Only $10"?

Would you tell newbies to buy whatever meter they want, marked with false safety markings or not, but stay away from things they don't know about?

Oh wait, you are saying that. You are telling people who don't know what is safe or not to ignore false safety ratings.......

I shall avoid calling people names. I will leave that to you since it seems like you have a lot of experience in that subject.




I do understand that you mean well, and wish to save people from trouble. That is a good thing.

BUT- you fail badly when it comes to one most imortant thing.
 You don't understand a shit about basic psychology.

When you give the impression that you will drop dead or your house will be a smoking pile of ash just because you use a non-approved multimeter you fail. Anyone with half a brain will know that it is not true. If it had been true it would have been widely known. When a beginner reads such scaremongering he wil ask himself "is this true?"

The obvious answer will be "no, it is not true". Therefore the beginner will think that you don't understand what you are talking about, and not pay any attention to what you really want him to understand.

So, the way you act, in the name of educating, is infact extremely counterproductive.

I myself prefer to spend my words on helping people to understand why. Long time experience has told me that it is more productive than to write a lot of words most people coose to ignore







And - you didn't answer my question in the post you quoted



So, why don't you spend your time telling beginners to stay away from what they are not allowed to do instead of all the scaremongering?




All the "what about" examples you list have very little to do with electrical safety and multimeters, but they make good examples for those who want to spot scaremongers.

You mention cars. That is interesting. Do you always drive the latest cars with the most advanced safety technology?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 17, 2017, 07:47:55 am
I won't bother replying to your rather emotional response. I will let it stand by itself.

Edit:
If anyone can show me where I call people names, or attack people personally instead of the ideas presented, I will apologize immediately.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 17, 2017, 07:51:58 am
For those who are interested, there is a sticky thread which I started in helping people avoid meters that are not rated correctly. It is factual information without emotion and drama. It has not been updated for a long time but I feel compelled to make some updates soon. Please read this thread if you want and take what you want from the information. It is presented to help, nothing more:
http://www.eevblog.com/forum/testgear/a-list-of-multimeters-that-do-not-appear-to-meet-their-claimed-safety-specs/ (http://www.eevblog.com/forum/testgear/a-list-of-multimeters-that-do-not-appear-to-meet-their-claimed-safety-specs/)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 17, 2017, 08:10:09 am
I won't bother replying to your rather emotional response. I will let it stand by itself.

Edit:
If anyone can show me where I call people names, or attack people personally instead of the ideas presented, I will apologize immediately.

I am not emotional. I just want you to understand that the way you act is extremely counterproductive. You do obviously prefer to write "in big letters" so I felt that I should "adapt to the audience." Seems like you got the mesage.
From many of your posts on this forum I have got the impression that you are the "one with the answer"and have some difficulties with other peoples ideas.

If you had spent 10% of the words you have written about scaremongering on this forum on telling people about why, you would have gained thousands.



Since you can't manage to read your own text, I will paste it here "More idiotic reasoning."

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 17, 2017, 08:16:23 am
I won't bother replying to your rather emotional response. I will let it stand by itself.

Edit:
If anyone can show me where I call people names, or attack people personally instead of the ideas presented, I will apologize immediately.

Challenge accepted !!!   ;D
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 17, 2017, 08:17:17 am
I won't bother replying to your rather emotional response. I will let it stand by itself.

Edit:
If anyone can show me where I call people names, or attack people personally instead of the ideas presented, I will apologize immediately.


Since you can't manage to read your own text, I will paste it here "More idiotic reasoning."

Is that reasoning I am attacking, or the person? You are applying idiotic reasoning. I will not apologize for attacking poor reasoning. I am responding only because I respect the opinions of others and assume that idiotic reasoning can be corrected. I also correct my own idiotic reasoning regularly.

If I assume that idiotic reasoning cannot be corrected because the other person is beyond help, I don't bother trying.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 17, 2017, 08:21:16 am
In the interests of keeping this thread open for further discussions. (I.e. not giving the moderators, reason to close this thread).

Can we agree to disagree or something ?

Peoples opinions of safety and stuff like that, do vary. But it is best if it does not lead to arguments.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 17, 2017, 08:42:11 am
In the interests of keeping this thread open for further discussions. (I.e. not giving the moderators, reason to close this thread).

Can we agree to disagree or something ?

Peoples opinions of safety and stuff like that, do vary. But it is best if it does not lead to arguments.

I wish people would agree to disagree on simple things. When people asset that safety is not worth considering and the markings on a multimeter are not to be counted in the evaluation of a multimeter, then disagreement is necessary.

When people suggest that modifying a multimeter with the intent to improve its safety is a wise, logical, or good thing to do, and that suggestion this to newbies, this needs argument. I am here trying to educate and help those who don't know better. The others are trying to shut me down for trying to show people the caution they need to take, as in education. The opposing view is to throw care out the window and too bad if you ae too stupid to know better.

I will not back down on this. Disagreements have a place. Idiotic reasoning and advice to newbies to ignore safety is to be argued.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 17, 2017, 08:50:53 am
In the interests of keeping this thread open for further discussions. (I.e. not giving the moderators, reason to close this thread).

Can we agree to disagree or something ?

Peoples opinions of safety and stuff like that, do vary. But it is best if it does not lead to arguments.

It's no argument, a heated debate at best, let them resolve it,

they're both big boys with literary muscle with some VERY IMPORTANT points to back up that may benefit many here,

otherwise it will flare up again and again elsewhere at other posts,

how many are complaining or offended so far?


go Team Tronde!     :clap:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 17, 2017, 08:58:40 am
In the interests of keeping this thread open for further discussions. (I.e. not giving the moderators, reason to close this thread).

Can we agree to disagree or something ?

Peoples opinions of safety and stuff like that, do vary. But it is best if it does not lead to arguments.

I wish people would agree to disagree on simple things. When people asset that safety is not worth considering and the markings on a multimeter are not to be counted in the evaluation of a multimeter, then disagreement is necessary.

When people suggest that modifying a multimeter with the intent to improve its safety is a wise, logical, or good thing to do, and that suggestion this to newbies, this needs argument. I am here trying to educate and help those who don't know better. The others are trying to shut me down for trying to show people the caution they need to take, as in education. The opposing view is to throw care out the window and too bad if you ae too stupid to know better.

I will not back down on this. Disagreements have a place, Idiotic reasoning and advice to newbies to ignore safety is to be argued.

You have raised some good points, in this post.
Maybe I'm over-reacting, a bit.
Things have been civil in this thread, in all fairness.

Safety is very important.
But I guess, getting world-wide agreement, on what exactly safety is and what constitutes the correct level of safety. Varies from country to country.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 17, 2017, 09:01:10 am
Can we all agree that this meter and many like this should be de-rated to Cat 0.111 at 30 volts ?   :clap:

Same deal with the supplied leads... safe to assume they are not shop soiled Pomona seconds   ;D
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MK14 on July 17, 2017, 09:13:37 am
Can we all agree that this meter and many like this should be de-rated to Cat 0.111 at 30 volts ?   :clap:

Same deal with the supplied leads... safe to assume they are not shop soiled Pomona seconds   ;D

Part of the reason we have differing levels of safety expectancy. Is because we have a very varied and mixed audience on these forums.

On the one end of the spectrum you have Electronics professionals, who will ask, what the safest/best replacement fuses are to put in their expensive Fluke multimeter.

Then the other end of the spectrum, you can have amateur/beginner hobbyist level. Who maybe much less concerned about safety (unfortunately). Even though they probably have the most need for safe equipment, in the first place.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 17, 2017, 09:31:45 am
There is no fuse in the Fluke 101. I doesn't measure current. For that you need the Fluke 106 that doesn't heave diode measurment. Only the Fluke 107 has them all. Of course it's the most expensive. The are trying to upsell you really hard here.

Not really. There is genuine need for a voltage only meter in the electrical field. When you add current measurement you instantly make the meter more dangerous for the user and the equipment under test, as you can get the leads the wrong way around and short out your supply.
If I was an electrician I would deliberately buy a meter without current measurement.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 17, 2017, 09:38:14 am
Regarding making shunts, is it as simple as getting a high wattage, high accuracy resistor?

Yes.

And no.

There are dedicated current shunts available with very low resistance and four wire connection terminals for the circuit and the measurement. A search for current shunt will find many examples.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 17, 2017, 09:49:53 am
..There is genuine need for a voltage only meter in the electrical field. When you add current measurement you instantly make the meter more dangerous for the user and the equipment under test, as you can get the leads the wrong way around and short out your supply.
If I was an electrician I would deliberately buy a meter without current measurement.


Fluke 114 fan here, pre-tested leads and a T100 for those tasks   :-+

No current inputs means no (or less..)    'Fluke videos'   :o   type of problem 

That doesn't mean using these gives you a permit to be a confident prodder and ignore the usual 'don't trust anything or anyone' Safety Protocols!   

Fluke 114 has TRMS, MIN-MAX, an excellent Low Z function handy for ghost voltages and trip testing RCD/RCBO/GFCI,
and a good fast buzzer, and fwiw its readings pretty much agree with the 87 too
I doubt the 101 can touch it as an all rounder
ok, 114 is more money, but you only need ONE good meter for these tasks, come on don't be too cheap  :blah:

I'd rather risk the beefier 114 with it's standard quality Fluke leads going BANG! in my gloved hand or all over the shop,
than a 101, that resembles a pocket toy that no paying client would take seriously rocking up with one at a job     :wtf:  :palm:   :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 17, 2017, 11:28:40 am
There has been some discussion here about using an external current shunt to measure current where perhaps the meter cannot measure current directly (e.g. Fluke 101), and how this might relate to safety.

One important factor is that if you use a current shunt to measure current, you will (should) usually build the shunt directly into the circuit under test as a fixture. As such, the safety considerations now become considerations for the circuit and not the meter. Typically this situation should occur in a lab setting and not in the field. In the field you should probably be using a clamp meter.

Having installed the shunt into the circuit, you now can attach the meter test leads to the shunt and you have the same safety considerations with the meter as when probing any other voltage. Overall, everything should be much more controlled and predictable than trying to break a circuit and probe the current directly.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ejeffrey on July 17, 2017, 01:03:07 pm
People make a lot of noise about false CAT-ratings. Why don't the same people make a lot of noise about what really matters when it comes to electrical safety?

Most countries around the world have a lot of legal regulations about education and long-time experience specifying what kind of work you are allowed to do on almost ANY kind of electrical equipment or wiring.

My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

This is rather beside the point and this argument is without merit, but I am going to respond because it is also completely wrong.
 
That certainly isn't true in the US, and I don't believe it is true most places in the world.  I don't know about Norway -- maybe all the stories about the excessive regulations are true, but your description isn't true in most of the rest of Europe either.  In the US you can't operate as a professional electrician without a license, but you can do almost anything in your own house that doesn't require a building permit.  I know this isn't true everywhere, but I don't believe most places are nearly as strict as you suggest.  In most of the US that means that you can pull new circuits from the main breaker panel.  Even if you can't, you can repair existing wiring, and you can certainly measure it with a voltmeter even if you don't change anything (for instance to diagnose a problem for which you might hire an electrician to fix.

And pretty much all of the regulation that does exist stops at the wall outlet.  There is basically zero restriction on who can work on a mains powered electrical appliance.  Anyone can (legally) replace a worn power cord or troubleshoot a line operated power supply.  Of course in the CAT rating system that is only a CAT-II environment, but it is still a situation where you want a meter that is not adding any danger -- and meters with deceptive labeling are definitely something worth being upset about, even if they are totally functional for low voltage applications.

Likewise, there is no restriction (in the US) on who can work on high voltages that are not part of the power distribution system.  I have in the past worked on high voltage power supplies capable of generating from hundreds to thousands of volts.  They don't have the same power behind them as a main distribution panel, but you can still have quite a bit of energy stored in a capacitor.  There is zero certifications, regulations, or licenses for who can do that in the US.  Other countries do have mandatory engineering licenses to be a professional electronics engineer, but in most places that is only required if you are doing so professionally.  And again, it doesn't exist in the US.  There is absolutely reasons for hobbyists to have safely designed meters, even if they are not doing the specific things that the cat rating is designed for (i.e., working on power distribution networks).

I do sort of agree that many people make too big of a deal about it, as if there is no value to a meter without CAT-4 600V ratings.  There are plenty of uses for multimeters that are never anywhere near a high power / high voltage circuit. The majority of electronics hobbyists would be well served by a safety-low voltage meter, or at most one that honestly meets CATII-300V, and the features this little $25 meter has that make it attractive: high resolution and low ranges are specifically things that don't require high voltage surge capability.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 17, 2017, 01:58:12 pm
Appreciate your input joe, all read!  ;) Big fan of your robustness testing videos.


Yet more suggestions for meters to test in the future: Chauvin Arnoux MTX 32xx or any of the clamshell style ones (another major European manufacturer akin to Gossen)

I think someone else asked me about one of these some time ago.  Maybe that was you.  I looked for a distributor.  There is very little info on them.  A little advice, invoking the Gossen brand as a comparison is not a good way to sell me on a product.  It will take some time to get the bad taste out of my mouth over that ordeal.   Who knows, maybe they are actually doing something on their end.   

Why do you call it a clamshell?  I would assume it folds up based on this.    Looking over their products, I think if I were to buy one, it would be the OX 5042.  Of course when I go to the following and select the Technical document, I get 404Not Found.  Giving me lots of confidence in them from the start.

http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx (http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx)


       
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 17, 2017, 03:14:49 pm
Of course when I go to the following and select the Technical document, I get 404Not Found.  Giving me lots of confidence in them from the start.

I did find this: (in French, though)

http://www.handscope.chauvin-arnoux.com/Portals/0/pdf/DT_Handscope_Ed01_FR.pdf (http://www.handscope.chauvin-arnoux.com/Portals/0/pdf/DT_Handscope_Ed01_FR.pdf)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: analogo on July 17, 2017, 06:27:56 pm
One additional detail: a few months ago I bought an UT136 on the same premises (nice meter for the price) - I did one mistake and the ohms/diode/continuity ranges are gone.

Which error?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 09:12:06 pm
There has been some discussion here about using an external current shunt to measure current where perhaps the meter cannot measure current directly (e.g. Fluke 101), and how this might relate to safety.

It's MUCH safer because it eliminates a whole class of errors.

ie. You're very unlikely to connect your shunt to your mains distribution panel.   :popcorn:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: WackyGerman on July 17, 2017, 09:13:49 pm
Well it is another cheapy crappy multimeter which doesn t meet the safety regulations and labelled with the wrong CAT rating . It s built down to the price with shitty input jacks , tiny little fuses and no input protection . It s not worth the money because it will not lasting a long time , it is dangerous to use because the uA range shares the same jack with voltage ranges . Don t buy this shit , it s a waste of money .
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 09:16:37 pm
My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

Well:
a) A 1.5V battery has a CAT rating.
b) Nobody needs a license to open up a power supply or anything else that plugs into a mains socket. That's CAT II (or even CAT III) right there.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: WackyGerman on July 17, 2017, 09:34:51 pm
My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

Well:
a) A 1.5V battery has a CAT rating.
b) Nobody needs a license to open up a power supply or anything else that plugs into a mains socket. That's CAT II (or even CAT III) right there.

You can open it up and measure at your own risk . But if something badly happens like a fire it will bring you to the justice
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 17, 2017, 09:37:15 pm
Appreciate your input joe, all read!  ;) Big fan of your robustness testing videos.


Yet more suggestions for meters to test in the future: Chauvin Arnoux MTX 32xx or any of the clamshell style ones (another major European manufacturer akin to Gossen)

I think someone else asked me about one of these some time ago.  Maybe that was you.  I looked for a distributor.  There is very little info on them.  A little advice, invoking the Gossen brand as a comparison is not a good way to sell me on a product.  It will take some time to get the bad taste out of my mouth over that ordeal.   Who knows, maybe they are actually doing something on their end.   

Why do you call it a clamshell?  I would assume it folds up based on this.    Looking over their products, I think if I were to buy one, it would be the OX 5042.  Of course when I go to the following and select the Technical document, I get 404Not Found.  Giving me lots of confidence in them from the start.

http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx (http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx)


       

Looks like I'm too late, the clamshell style meters (attached below) are listed as discontinued most places. Always been curious how the input protection looks like in those (and performs). Now replaced with MTX 3290.

Compared with Gossen because I suspect a similar ordeal, but isn't that just fun?  ;D

EDIT: In the US it seems to go by the model AEMC 2125.75,  still sold by AEMC on Amazon https://www.amazon.com/AEMC-2125-75-Multimeters-000-count-Graphical/dp/B00A8P6GOG (https://www.amazon.com/AEMC-2125-75-Multimeters-000-count-Graphical/dp/B00A8P6GOG)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 17, 2017, 10:00:20 pm
Well it is another cheapy crappy multimeter which doesn t meet the safety regulations and labelled with the wrong CAT rating . It s built down to the price with shitty input jacks , tiny little fuses and no input protection . It s not worth the money because it will not lasting a long time , it is dangerous to use because the uA range shares the same jack with voltage ranges . Don t buy this shit , it s a waste of money .

You may not want to buy it, but please refrain from telling me what to do.

I own a very nice set of jeweler's screwdrivers. They are very precise and handy to use. And, believe it or not, I do not use them to work on mains outlets, although those screwdrivers do not even bear a warning label cautioning me against that use. -- Horses for courses, and that is how I intend to use the AN8008 and my other meters as well.

By the way, for even more credibility, I recommend to cut back on the use of swear words and to omit the spaces before punctuation marks.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on July 17, 2017, 10:05:17 pm
It s not worth the money because it will not lasting a long time.

How do you know ?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: WackyGerman on July 17, 2017, 10:17:56 pm
Just look at the input jacks . They are not fitted properly and if you put in a plug you will push in the input jack and stress the solder joint of it on the board and it will break soon . The second problem is the lack of input protection . If a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 10:23:35 pm
Just look at the input jacks . They are not fitted properly and if you put in a plug you will push in the input jack and stress the solder joint of it on the board and it will break soon . The second problem is the lack of input protection . If a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up

The first actually happened to a DT830 to me. It's not the solder joint that cracked though, it was the input jack metal holder part (not sure what it's called), somewhere in the middle (between the input jack and solder joint). I'm not sure if replacement parts can be purchased.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: WackyGerman on July 17, 2017, 10:49:04 pm
Oh that s even worse . A broken solder joint could be repaired but the input jack itself not . I don t think that you could buy spare parts for cheap multimeters , it would be too expensive for the manufacturer to keep them on stock . Anyway it would drive me nuts to repair the multimeter often before using it  :scared:
In my opinion good input jacks are an important point when buying a multimeter
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 17, 2017, 10:50:57 pm
Just look at the input jacks . They are not fitted properly and if you put in a plug you will push in the input jack and stress the solder joint of it on the board and it will break soon .

Not if they're properly supported by the back of the case.

Which they are:
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=332697;image)

(OK, that's an AN8002 but it will be the same)

The second problem is the lack of input protection . If a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up

Nope. These have been tested with joe's sparker and survived perfectly.

http://www.youtube.com/watch?v=HrcxnbkkhYg (http://www.youtube.com/watch?v=HrcxnbkkhYg)

That one didn't fail until 3000V.

I think Everybody here knows that these meters aren't good for working with 230V AC. There are plenty of warnings in the video. For working with 5V, 12V, Arduinos, etc., they're fine.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 17, 2017, 11:52:10 pm
I think Everybody here knows that these meters aren't good for working with 230V AC. There are plenty of warnings in the video. For working with 5V, 12V, Arduinos, etc., they're fine.

I learned a bit in this thread. In fact, I didn't know how dangerous (not whether or not, just how much) it was to use a multimeter on mains (although anything with mains always gets people careful with reason). I'm just not sure how it compares to other "cheap methods" such as those 'dangerous voltage detecting screwdrivers' (I guess you know what I mean). Non contact ones should be safe, but are not always dependable. I'm sure people use both in practice, as anything is safer than using your hand (or worse, both hands) to check if there's voltage or not.

Videos from Fluke and Joe and others can be helpful to see some of the dangers with some meters (e.g. Fluke exploding the DT830). Although, I have yet to learn how many of it applies to using the meter on proper range (voltage range), in which case I assume other protections come into play (case, probes, etc), and not e.g. which fuse is used. Of course, I need to watch a bit more and I'm sure I'll find out. :) As far as measuring mains current, if needed for some reason, seems safer with a clamp meter (plus, no need to cut a wire), as even a cheap clamp meter you're not connecting to the circuit.

I still like that there are cheap meters that can measure current, like the DT830, since it's quite useful for testing LEDs and other safe but interesting projects. It's always helpful to know the current, and some meters that can do both at the same time (e.g. USB power meters) can be very useful too. A meter like AN8002 or 8008 both seem to offer great advantages. Things like more accuracy (more or less important), capacitance, frequency, temperature (8002) all add a lot of functionality even for true beginners (on this forum, I think that sometimes a beginner could mean a knowledgeable, experienced person, or someone without too much experience that has finished formal EE education or such).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 18, 2017, 12:18:59 am
Testing these meters is a bit like crash testing cars, various models will perform better than others. Its really a question of what the person can afford and also of course what they are going to be used for. For the general hobbyist working with electronics I would say that most are perfectly suitable as you do not generally at that level of involvement come across large amounts of energy.

If however you were using these professionally as a matter of course then you should always get the very best you can, weighing up all the factors such as is it going to be bench kept, chucked in a toolbox and used away from the bench, is it going to be used on high energy sources or just checking voltages etc on low power electronics etc, it all will have a bearing.

So basically at the end of day, until there are proper standards testing and better ways of enforcing them, common sense must prevail. If we ever get to the position of having better standards enforcement, then the cost of the better meters will drop dramatically because of the scale of economies will come into play for things like HRC fuses etc. that will benefit everyone.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: madires on July 18, 2017, 12:23:56 am
FYI, a sparky uses something like a Duspol for mains, and not a DMM. I think it's amazing how much value you get with the AN8008. The missing delta function and the lack of mA ranges is disappointing, but acceptable for that price. And regarding the poor input protection, I've had much more expensive DMMs with worse input protection.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 12:43:17 am
Videos from Fluke and Joe and others can be helpful to see some of the dangers with some meters (e.g. Fluke exploding the DT830). Although, I have yet to learn how many of it applies to using the meter on proper range (voltage range)

Even the crappy meter in the Fluke video was OK on the proper volts range. It only exploded when he switched to a 'bad' range.

(but I'd be very unhappy holding one in my hand with 466V high energy AC going through it...  :scared: )

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 18, 2017, 01:31:44 am
I would love to see someone replicate Fluke's demonstration, 750 VAC high-current capable supply with the meter in 200 ohms range.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 18, 2017, 01:41:55 am
I would love to see someone replicate Fluke's demonstration, 750 VAC high-current capable supply with the meter in 200 ohms range.

There's also a few different PCBs with different DT830 models. I'd be interested if those variations make things more or less spectacular. On the other hand, I doubt someone would recreate such a supply just to test some DT's. :)

Edit, maybe you meant AN8008 instead. Not that it changes things in terms of that being a costly and probably not very safe thing to have.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 02:00:10 am
I would love to see someone replicate Fluke's demonstration, 750 VAC high-current capable supply with the meter in 200 ohms range.
There's also a few different PCBs with different DT830 models. I'd be interested if those variations make things more or less spectacular.

Yep.

Even with the exact same model/batch it might not go exactly the same way due to variations in the probes, the soldering, etc.

On the other hand, I doubt someone would recreate such a supply just to test some DT's. :)

I bet Youtube disagrees with you.  :popcorn:

Edit:
http://www.youtube.com/watch?v=M-FZP1U2dkM (http://www.youtube.com/watch?v=M-FZP1U2dkM)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 18, 2017, 02:04:04 am
I can only do 300 mA at 750 AC, but my smoke detector is wired in parallel with the whole building and alerts the fire department  :(
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 18, 2017, 02:34:39 am
People make a lot of noise about false CAT-ratings. Why don't the same people make a lot of noise about what really matters when it comes to electrical safety?

Most countries around the world have a lot of legal regulations about education and long-time experience specifying what kind of work you are allowed to do on almost ANY kind of electrical equipment or wiring.

My humble guess is that only a very few of you are legally allowed to touch anything that will require a multimeter with a CAT-rating.

This is rather beside the point and this argument is without merit, but I am going to respond because it is also completely wrong.
 
That certainly isn't true in the US, and I don't believe it is true most places in the world.  I don't know about Norway -- maybe all the stories about the excessive regulations are true, but your description isn't true in most of the rest of Europe either.  In the US you can't operate as a professional electrician without a license, but you can do almost anything in your own house that doesn't require a building permit.  I know this isn't true everywhere, but I don't believe most places are nearly as strict as you suggest.  In most of the US that means that you can pull new circuits from the main breaker panel.  Even if you can't, you can repair existing wiring, and you can certainly measure it with a voltmeter even if you don't change anything (for instance to diagnose a problem for which you might hire an electrician to fix.

And pretty much all of the regulation that does exist stops at the wall outlet.  There is basically zero restriction on who can work on a mains powered electrical appliance.  Anyone can (legally) replace a worn power cord or troubleshoot a line operated power supply.  Of course in the CAT rating system that is only a CAT-II environment, but it is still a situation where you want a meter that is not adding any danger -- and meters with deceptive labeling are definitely something worth being upset about, even if they are totally functional for low voltage applications.

Likewise, there is no restriction (in the US) on who can work on high voltages that are not part of the power distribution system.  I have in the past worked on high voltage power supplies capable of generating from hundreds to thousands of volts.  They don't have the same power behind them as a main distribution panel, but you can still have quite a bit of energy stored in a capacitor.  There is zero certifications, regulations, or licenses for who can do that in the US.  Other countries do have mandatory engineering licenses to be a professional electronics engineer, but in most places that is only required if you are doing so professionally.  And again, it doesn't exist in the US.  There is absolutely reasons for hobbyists to have safely designed meters, even if they are not doing the specific things that the cat rating is designed for (i.e., working on power distribution networks).

I do sort of agree that many people make too big of a deal about it, as if there is no value to a meter without CAT-4 600V ratings.  There are plenty of uses for multimeters that are never anywhere near a high power / high voltage circuit. The majority of electronics hobbyists would be well served by a safety-low voltage meter, or at most one that honestly meets CATII-300V, and the features this little $25 meter has that make it attractive: high resolution and low ranges are specifically things that don't require high voltage surge capability.

What I know, is that the Norwegian regulations for electrical wiring and safety are harmonized as much as possible with the EU regulations.

Here an "amateur" is allowed to change 2-pole plugs with or without PE on equipment wires meant for no more than 25A, simple repair of small table lamps with flexible wires, connect a lamp hanging in a hook to the wiring if the connection is not considered a permanent part of the installation.

Equipment fed from no more than 50V is allowed given maximum power consumption is no more than 200VA, connection to mains is via wall socket, and the user instructions are strictly followed. I.e. no diy equipment.

All kind of repair is covered by specific regulations regarding education and work experience.

I have seen similar descriptions from other European countries as well, so I guess diy is more limited than many people are aware of. The Norwegian regulation refer to EU-directive 2005/36/EC.

Norwegian regulation (in Norwegian)
https://lovdata.no/dokument/SF/forskrift/2013-06-19-739

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 18, 2017, 05:04:04 am
I won't bother replying to your rather emotional response. I will let it stand by itself.

Edit:
If anyone can show me where I call people names, or attack people personally instead of the ideas presented, I will apologize immediately.


Since you can't manage to read your own text, I will paste it here "More idiotic reasoning."

Is that reasoning I am attacking, or the person? You are applying idiotic reasoning. I will not apologize for attacking poor reasoning. I am responding only because I respect the opinions of others and assume that idiotic reasoning can be corrected. I also correct my own idiotic reasoning regularly.

If I assume that idiotic reasoning cannot be corrected because the other person is beyond help, I don't bother trying.
The fact that you mention peoples grammar (while they are not being native) and call peoples friends/technical contacts are imaginary says enough.
Pretty disrespectful.

Just only saying that safety rules are holy as the holiest god is just lack of any reasoning at all.
(and you also clearly don't have a clue about any international regulations and how different they are)
That way we would still living in caves.

Anyway, not worth putting energy into this.
I would say to the rest go on and try to help each other with new ideas.
Like I said before it's not productive and only gives a very negative vibe to all of this.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: free_electron on July 18, 2017, 06:02:42 am
Just bought two of em. Don't give a flying F about Cat rating. i don't do anything above 12 volt and 1 ampere anyway. if i do : i have flukes and agilents.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 18, 2017, 06:07:04 am
Well it is another cheapy crappy multimeter which doesn t meet the safety regulations and labelled with the wrong CAT rating . It s built down to the price with shitty input jacks , tiny little fuses and no input protection . It s not worth the money because it will not lasting a long time , it is dangerous to use because the uA range shares the same jack with voltage ranges . Don t buy this shit , it s a waste of money .

You may not want to buy it, but please refrain from telling me what to do.

I own a very nice set of jeweler's screwdrivers. They are very precise and handy to use. And, believe it or not, I do not use them to work on mains outlets, although those screwdrivers do not even bear a warning label cautioning me against that use. -- Horses for courses, and that is how I intend to use the AN8008 and my other meters as well.

By the way, for even more credibility, I recommend to cut back on the use of swear words and to omit the spaces before punctuation marks.
Nicely put, at the end of the day you would have to be a complete and utter dummy not to understand the differences between something costing £20 and something that costs £500, especially when they both purport at least in the main part of say volts, current and resistance, to do the same thing and probably with similar ratings. Clearly the cost differences are not just down to things like the accuracy of them and anyone buying a cheaper meter must comprehend that corners have been cut in order to meet the price point.

It cannot be that difficult either to design and produce something that would for all but the very worst conditions, contain all blast, fireball and debris etc within the case with reasonable overload protection to protect against accidental minor overloads, without pushing the price too high?

I very much doubt if any of the famous Simpson or the Avo meters would withstand the energy levels that those meters were exposed to but are we all going to stop using them now? Of course not.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 18, 2017, 09:04:17 am
FYI, a sparky uses something like a Duspol for mains, and not a DMM. I think it's amazing how much value you get with the AN8008. The missing delta function and the lack of mA ranges is disappointing, but acceptable for that price. And regarding the poor input protection, I've had much more expensive DMMs with worse input protection.

Sorry mate, can't buy that  ::)

The sparkies over there are either not making money to also afford a proper CAT class DMM to do their job better informed and verified,

or not aware of its abilities perhaps ?   :-//

A 'Duspol' for all the viewers here btw is a dual probe contact voltage/continuity tester,
and anyone playing with electrics should own a good one..or two if you enjoy life and prefer to avoid hospitals and funeral parlors,
relying on just one Duspol and the condition of the batteries

www.benning.de/duspol-voltage-testers-en.html (http://www.benning.de/duspol-voltage-testers-en.html)

www.fluke.com/fluke/uken/electrical-testers/Electrical-Testers/T90-T110-T130-T150-Voltage-and-Continuity-Testers.htm?PID=73757 (http://www.fluke.com/fluke/uken/electrical-testers/Electrical-Testers/T90-T110-T130-T150-Voltage-and-Continuity-Testers.htm?PID=73757)


Let's cross fingers the sparkies over there get an insulation tester, gloves and eye protection before their final Birthday or Christmas    :-+

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 18, 2017, 10:20:37 am
Of course when I go to the following and select the Technical document, I get 404Not Found.  Giving me lots of confidence in them from the start.

I did find this: (in French, though)

http://www.handscope.chauvin-arnoux.com/Portals/0/pdf/DT_Handscope_Ed01_FR.pdf (http://www.handscope.chauvin-arnoux.com/Portals/0/pdf/DT_Handscope_Ed01_FR.pdf)

I assumed for CAT III 600 it would be certified but appears it's not.  No manuals on-line that I could find.   They don't appear to have an Amazon store.   Seems more effort than it's worth at this time. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 18, 2017, 10:26:50 am
Appreciate your input joe, all read!  ;) Big fan of your robustness testing videos.


Yet more suggestions for meters to test in the future: Chauvin Arnoux MTX 32xx or any of the clamshell style ones (another major European manufacturer akin to Gossen)

I think someone else asked me about one of these some time ago.  Maybe that was you.  I looked for a distributor.  There is very little info on them.  A little advice, invoking the Gossen brand as a comparison is not a good way to sell me on a product.  It will take some time to get the bad taste out of my mouth over that ordeal.   Who knows, maybe they are actually doing something on their end.   

Why do you call it a clamshell?  I would assume it folds up based on this.    Looking over their products, I think if I were to buy one, it would be the OX 5042.  Of course when I go to the following and select the Technical document, I get 404Not Found.  Giving me lots of confidence in them from the start.

http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx (http://www.handscope.chauvin-arnoux.com/en/documents/publications.aspx)


       

Looks like I'm too late, the clamshell style meters (attached below) are listed as discontinued most places. Always been curious how the input protection looks like in those (and performs). Now replaced with MTX 3290.

Compared with Gossen because I suspect a similar ordeal, but isn't that just fun?  ;D

EDIT: In the US it seems to go by the model AEMC 2125.75,  still sold by AEMC on Amazon https://www.amazon.com/AEMC-2125-75-Multimeters-000-count-Graphical/dp/B00A8P6GOG (https://www.amazon.com/AEMC-2125-75-Multimeters-000-count-Graphical/dp/B00A8P6GOG)

One strange looking meter.    One review: "Nice but quirky meter."  I don't see the appeal.   
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 18, 2017, 11:06:56 am
...
(OK, that's an AN8002 but it will be the same)
The second problem is the lack of input protection . If a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up

(OK, that's an AN8002 but it will be the same)

Nope. These have been tested with joe's sparker and survived perfectly.
...
That one didn't fail until 3000V.
...

I had the gun running by the time I bought that meter which is more harsh of a test than the little grill starter.  But it's pretty close to what the IEC calls for.  It's yet to damage a meter.   I was impressed with how well the 8002 held up.  3KV, it's double what that 87V failed at and with just a PTC and a couple of diodes. These transients are applied to every mode the meters has except the ones that are related to current measurement.   

Of course someone is bound to think that means it would survive being hooked to the 2KV secondary of their MOT because after all, 2KV is a KV less than 3KV.  Plenty of head room.   It won't be.  The MOT will win the battle.   And we can't forget about the special ones that claim I am driving DC into the meters or directly coupling capacitors to them so when they fail it's because I exceeded the 600V the meter was rated to.    The 3KV transient that the 8002 was subjected to is the same transient I have applied to the last 40 or so meters, many of which have survived.   If you want a more robust meter, they are out there. 


While you can obviously post that the 8008 will survive to the same levels as the 8002, what proof do you have of this?   Consider when I ran the Amprobe AM530.  It was not near as robust at that lower priced AM510.   The 87V was no where near as robust as every other Fluke I have looked at.  At least it was reparable.  The vast majority are not.   Anyway, rather than post what you claim as fact based on your feelings, IMO it's better to run the tests and let the data stand on it's own or add a qualifier to your statements.  "My guess is the 8008 would be as robust as the 8002 because ....."  People would then know you really don't know and not take it as fact.  Or, post the data you have to prove it.    Sorry for the rant.       
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 07:06:30 pm
While you can obviously post that the 8008 will survive to the same levels as the 8002, what proof do you have of this?

I didn't say it would fail at the exact same levels.

The OP claimed that "if ...a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up".

I find that very unlikely.

You yourself say: "I had the gun running by the time I bought that meter which is more harsh of a test than the little grill starter.  But it's pretty close to what the IEC calls for.  It's yet to damage a meter."

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 18, 2017, 09:46:34 pm
While you can obviously post that the 8008 will survive to the same levels as the 8002, what proof do you have of this?

I didn't say it would fail at the exact same levels.

The OP claimed that "if ...a little static discharge goes into the multimeter or you accidently took the wrong function the ic will blow up".

I find that very unlikely.

You yourself say: "I had the gun running by the time I bought that meter which is more harsh of a test than the little grill starter.  But it's pretty close to what the IEC calls for.  It's yet to damage a meter."

"(OK, that's an AN8002 but it will be the same)"  Using the word same leads me to that your claim is they fail identically.   :-//  I really have no idea.

Yes, I ran all these tests including the new gun on the 8002 but that is no indicator that the 8008 would not be damaged. OP could very well be correct.  But again, they too have no data to back it up.  We end up with peoples feelings about it rather than facts. 

I need to buy a UNI-T or get a free HF meter to show that the new gun is even doing anything.   :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 10:09:34 pm
Yes, I ran all these tests including the new gun on the 8002 but that is no indicator that the 8008 would not be damaged. OP could very well be correct.  But again, they too have no data to back it up.  We end up with peoples feelings about it rather than facts. 

"It's yet to damage a meter" isn't data?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 18, 2017, 10:26:54 pm
No, that is an anecdote. The plural of anecdote is not data ;).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 10:47:54 pm
No, that is an anecdote. The plural of anecdotes is not data ;).

By that reasoning you might float off into space at any moment.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: jonovid on July 18, 2017, 10:50:11 pm
ANENG AN8008 DMM is ok by me! as it was tested by Dave!  unless you live in a Igloo, then the ANENG AN8002 DMM maybe 4 u.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on July 18, 2017, 10:59:50 pm
Is the true RMS accurate on this 8008 ? ( for measuring noise ), can anyone verify ?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 18, 2017, 11:05:38 pm
The plural of anecdotes is not data ;).

Anecdata?  ;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 18, 2017, 11:06:22 pm
By that reasoning you might float off into space at any moment.
If our knowledge of gravity was limited to 'someone has jumped, and seemed to fall down again' then yes, I would not exclude that as a possibility.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 18, 2017, 11:42:27 pm
By that reasoning you might float off into space at any moment.
If our knowledge of gravity was limited to 'someone has jumped, and seemed to fall down again' then yes, I would not exclude that as a possibility.

But if ten million people jumped and they all fell down again than you could use that result to make predictions without being branded a dangerous lunatic, right?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 19, 2017, 12:07:04 am
But if ten million people jumped and they all fell down again than you could use that result to make predictions without being branded a dangerous lunatic, right?
What if I was a professional athlete (high jumper)? Without knowing the energy they used, I can not be sure what the limits are. Maybe they were 10 million children? And any reasonably fit adult will be able to jump to the moon?

How many meters have you tested or have seen reports of being tested? What were the test conditions like? I would describe the difference between anecdotes and data as a well documented, reproducible procedure and a structured way of collection. If ten people said 'I measured resistance in auto-ranging mode across a full 9V alkaline battery brand X', and subsequently report if it failed or survived, then that would be data. Not necessarily data that would convince me that it would survive the same with higher voltages, but it would be data.

Saying 'I have not seen any reports' could be subject to a selection bias (are the people posting a representative sample of AN8008 customers? are people more likely to report success or failure?) and is very vague (how many people? what did they expose the meter to? what is their mains voltage? was the environment likely to trigger ESD?).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 12:11:56 am
If ten people said 'I measured resistance in auto-ranging mode across a full 9V alkaline battery brand X', and subsequently report if it failed or survived, then that would be data.

But when joe says, "It's yet to damage a meter", it isn't?

Got it.

OK, what if we took joe's actual results:
Code: [Select]
Pass
Pass
Pass
Pass
Pass
Fail
Pass
Pass
Fail
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Fail
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Fail
Pass
Fail
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Pass

What would that be called?  :popcorn:

What predictions could you make about an unknown, randomly chosen meter using that information?


How many meters have you tested or have seen reports of being tested? What were the test conditions like?

http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/ (http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 19, 2017, 01:02:17 am
OK, what if we took joe's actual results:
[snip]
What would that be called?  :popcorn:

What predictions could you make about an unknown, randomly chosen meter using that information?
Joe's result (including his documentation about his test setup and the actual meter models) would definitely be data. Using this to predict another random meter is tricky. If we assume that the group Joe tested is representative for the group we pick the random meter from, I would say that the meter has an expected pass chance of 38/43th. However, if Joe only ever tested Fluke meters which are the definition of perfection (;)), and now started tested $5 meters, that expectation may be way off.

You might be able to improve the estimate if you split the results by manufacturer or price class. How many of the meters that Joe tested with the current procedure were around the $20 mark? And even then, you can only figure out an expected pass chance. A meter that is 90% likely to pass a test can still fail.

If Joe is not comfortable in extrapolating the data to an untested meter, then I would not extrapolate the data either.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 01:05:21 am
However, if Joe only ever tested Fluke meters which are the definition of perfection (;)), and now started tested $5 meters, that expectation may be way off.

Really? The Fluke 87V failed a test that this meter's $15 sibling passed.

FWIW, here are the PCBs of the two meters in question (AN8002 and AN8008).
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333107;image)

Me? I've got $10 that says the AN8008 will pass the sparker test.


PS: Is that a Rubycon capacitor?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on July 19, 2017, 01:33:44 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 02:00:07 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

Join the club :-)

Edit: I just noticed they ship them without battery   :(

I need to order a '23A', 12V battery as well.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 19, 2017, 02:00:22 am
I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html).

Hmm, they actually state that the insulation on those test leads is silicone! Curious to see what I will get with my meter when it arrives. But then, they also claim the meter to be CAT II 1000V rated...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 19, 2017, 03:18:58 am
But when joe says, "It's yet to damage a meter", it isn't?

Got it.

OK, what if we took joe's actual results:
Code: [Select]
Pass
Pass
Pass
Pass
Pass
Fail

I believe there is some confusion that I am partly to blame for.  If you go back and read my comments about not damaging a meter yet, these refer to the new homemade ESD gun, not the piezo ignitor.   While both devices put out a fairly fast transient, if you followed along when I tested the 181A and later was working on the new gun, you are aware that the gun can supply much higher current levels than the piezo. 

The data that you present I assume came from my spreadsheet and you just missed on meter in the beginning.   This data is for the piezo ignitor, not the new gun.   To avoid this confusion, I have added a new column to the spreadsheet for the new gun.

I had planned to stop using the piezo ignitor but people have requested that I leave it in.  I think this stems partly from my comments about how no meter should ever be damaged by it and that we have seen so many UNI-Ts fail this test.   It's pretty much what I consider to be the least stressful test I have ran on the meters.

OK, what if we took joe's actual results:
[snip]
What would that be called?  :popcorn:

What predictions could you make about an unknown, randomly chosen meter using that information?
Joe's result (including his documentation about his test setup and the actual meter models) would definitely be data. Using this to predict another random meter is tricky. If we assume that the group Joe tested is representative for the group we pick the random meter from, I would say that the meter has an expected pass chance of 38/43th. However, if Joe only ever tested Fluke meters which are the definition of perfection (;)), and now started tested $5 meters, that expectation may be way off.

You might be able to improve the estimate if you split the results by manufacturer or price class. How many of the meters that Joe tested with the current procedure were around the $20 mark? And even then, you can only figure out an expected pass chance. A meter that is 90% likely to pass a test can still fail.

If Joe is not comfortable in extrapolating the data to an untested meter, then I would not extrapolate the data either.

I agree.  Even if we are all talking about the piezo and not the new gun the sample size is just too small to say much about all meters available.  Even if I had ran more brands and models, just from the little testing I have done, I would be VERY hesitant to extrapolate how new meters would perform.     

Considering that 3 or the 5 meters that failed the piezo test were UNI-Ts, I fully agree that splitting the results would improve the estimate.  Still my confidence factor would be poor.   

However, if Joe only ever tested Fluke meters which are the definition of perfection (;)), and now started tested $5 meters, that expectation may be way off.

Really? The Fluke 87V failed a test that this meter's $15 sibling passed.

FWIW, here are the PCBs of the two meters in question (AN8002 and AN8008).

Me? I've got $10 that says the AN8008 will pass the sparker test.
PS: Is that a Rubycon capacitor?

I agree that the 87V is really a flyer (outside the norm) from what I have seen with Fluke.   Similar to the UNI-T 139c that actually fairs well in my tests compared with the vast majority of UNI-T DVMs I have looked at.    I wonder if the new gun would damage one..  Anyway, this is exactly why even within a brand, I would be hesitant to comment about how an untested meter would perform. 

If you now understand that there are two different ESD tests, one with the piezo grill ignitor and one with the new gun, what are you considering the "sparker test"?   

ESD is a fun one to design for.  There's a fair difference between the two PCBs you show. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: metrologist on July 19, 2017, 03:31:18 am
I do not think you can extrapolate Joe's tests to any other model meter, even within the same price class, brand, or even model series (as the Fluke 87V seems to show). A data point of one?

I like Joe's video format and editing. I think 20% more could be shaved off, with double your time  :-DD. I like it, to the point  :-+

"There's a fair difference between the two PCBs you show." Just one small change would seem to have the potential to make or break the result. Maybe even the angle of how a component is placed in the exact same model?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on July 19, 2017, 03:37:52 am
I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html).

Hmm, they actually state that the insulation on those test leads is silicone! Curious to see what I will get with my meter when it arrives. But then, they also claim the meter to be CAT II 1000V rated...
That is why I chose to pay a bit more extra (about $0.50) when compared to a few other sellers that did not mention silicone on the description.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 03:55:04 am
If you now understand that there are two different ESD tests, one with the piezo grill ignitor and one with the new gun, what are you considering the "sparker test"?

Either will do, but I think you should keep doing with the grill igniter simply because it's become a de-facto yardstick. It's difficult to compare new/old results if we switch to something else.

Do those igniters wear out with time? It might be good to measure the sparks and make sure it's holding up, producing sparks just like the first day.

There's a fair difference between the two PCBs you show.

They've moved the buzzer and a few components around, yes.

When you really zapped the AN8002 the major trace damage happened around the area of the buzzer. Maybe they moved the buzzer away to improve that area of the PCB.  :popcorn:

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333138;image)

Regardless, the thing that failed first on that meter was the transistor clamp - nothing to do with PCB spacing or layout. If the transistors in the AN8008 are the same then I'd guess it will fail in the same way.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 04:47:08 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 19, 2017, 04:56:24 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.

I have no idea if they are using different chips and if one is better, but I would think it would at least be as reliable as a DT830. Looking at the image, maybe the input jacks are even placed better (directly on the PCB) and may last longer if probes are moved around often. That said, I can't say which of the really low end meters (e.g. sub $6) offer best value. This one is the smallest and offers battery measurement, some offer temperature measurement, some offer a backlight but no battery or temperature measurement, and which is safer... who knows. :)

Is there something that should/could be added here?

(http://i.imgur.com/NoivMnz.png)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 05:04:22 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.

Correct. No false CAT labels, just a tiny meter.

Case looks decent. The PCB looks OK in the pics. I like that the amps ranges are on a separate input jack. Looks to have a decent battery tester. It has a continuity buzzer, unlike most DT830Bs. Buzzer is mounted on a nice little holder. Looks calibratable (although that works both ways - it will likely drift more with that cheapass pot)

And .... it's TINY!  :popcorn:

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333140;image)

I hope there's plenty of solder on the other side of the board to hold the input jacks in place.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333148;image)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on July 19, 2017, 05:10:13 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.
I like this fact as well and bought it for the curiosity. If its interior is as clean as the one shown in the photograph, I would consider it a bonus (it's been a while since the Harbor Freight DT830s were clean inside).

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333142)
What happened? Hopefully no hurt feelings were involved between the parties...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on July 19, 2017, 05:12:50 am
See what you guys did? All this chat about Aneng made me curious about their gear.  :-DMM

My hobby capex of this month wouldn't allow for an 8008, thus I went for its mini-me version (https://www.aliexpress.com/item/Handheld-Mini-Pocket-DMM-Digital-Multimeter-AC-DC-Volt-Amp-OHM-Test-Meter-Voltmeter-Ammeter-with/32811782529.html) and the cable accessory set (https://www.aliexpress.com/item/16pcs-Set-Multifunction-Digital-Multimeter-Probe-Silicone-Test-Lead-Cable-Alligator-Burn-Resistant-Digital-Multimeters-Test/32678202961.html). Everything less than US$9.00 with ePacket shipping (with tracking #).

I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.

I have no idea if they are using different chips and if one is better, but I would think it would at least be as reliable as a DT830. Looking at the image, maybe the input jacks are even placed better (directly on the PCB) and may last longer if probes are moved around often. That said, I can't say which of the really low end meters (e.g. sub $6) offer best value. This one is the smallest and offers battery measurement, some offer temperature measurement, some offer a backlight but no battery or temperature measurement, and which is safer... who knows. :)

Is there something that should/could be added here?
Nice! It can be modded from the get-go! :)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 05:14:12 am
Is there something that should/could be added here?

And I wonder what the mystery 8-pin chip is.  :popcorn:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 05:27:19 am
You'd think they'd choose one with a little bit better soldering for the web store... 

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333146;image)

(I'm guessing that trimmer is hand-soldered)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 19, 2017, 07:09:26 am
I see no CAT ratings claimed i the ad for that meter. If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price.

Beginner:
Look at this cool little multimeter I just got from China. It  has no CAT-ratings, so I will only use it for my arduino.

OR

Beginner:
Look at this cool little multimeter I just got from China. Let's see how many volts it is in the wall socket.


 :popcorn:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 07:22:28 am
Beginner:
Look at this cool little multimeter I just got from China. Let's see how many volts it is in the wall socket.

It's a rite of passage - measure mains AC with a dangerous multimeter!

(hey, at least all the dangerous ranges are on a separate input jack...)

I'm also a fan of the way the screw-together probes in the kit have a little tiny bit of exposed metal at the other end.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333173;image)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 19, 2017, 07:26:37 am
Beginner:
Look at this cool little multimeter I just got from China. It  has no CAT-ratings, so I will only use it for my arduino.

I am thoroughly impressed with the Norwegian "beginners", who all know what a CAT rating is.
(And who actively look for a CAT rating, notice its absence, and draw the right conclusions.)  ::)

Come on, a beginner is just as likely to poke at a wall outlet with that unrated meter as with an AN8008. And just as unlikely to electrocute himself doing it.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 07:35:09 am
Come on, a beginner is just as likely to poke at a wall outlet with that unrated meter as with an AN8008. And just as unlikely to electrocute himself doing it.

In the real world both of those are far less likely than using a DT830B.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 19, 2017, 07:37:29 am
Beginner:
Look at this cool little multimeter I just got from China. It  has no CAT-ratings, so I will only use it for my arduino.

I am thoroughly impressed with the Norwegian "beginners", who all know what a CAT rating is.
(And who actively look for a CAT rating, notice its absence, and draw the right conclusions.)  ::)

Come on, a beginner is just as likely to poke at a wall outlet with that unrated meter as with an AN8008. And just as unlikely to electrocute himself doing it.

I am more impressed by Lightages belief in "the power of CAT-markings".  As you can see, he finds this meter to be suitable for beginners because it has no fake CAT-rating.

 :popcorn: :popcorn: :popcorn:

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 08:03:48 am
Harbor Freight also gives away these beauties. The convenient on/off switch means the selector can literally be in any position when junior connects the probes.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=333175;image)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 19, 2017, 08:22:21 am
Harbor Freight also gives away these beauties. The convenient on/off switch means the selector can literally be in any position when junior connects the probes.



That's no problem. It has no CAT-rating, so junior will not use it for anything dangerous. Or have I got it wrong ?
 :popcorn:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 09:51:27 am

I am more impressed by Lightages belief in "the power of CAT-markings".  As you can see, he finds this meter to be suitable for beginners because it has no fake CAT-rating.

 :popcorn: :popcorn: :popcorn:

More putting words in other's mouths, troll.........

You know trolling here, lying about what people say or what their intent is, are reasons for discipline here. Keep it up.....
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 19, 2017, 01:10:51 pm
is everyone that calls you out on anything a 'troll' ? 

Tronde delivers the goods backing up what he types,

why is he a troll and you're not ? 

It borders on forum slander  :--

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 19, 2017, 01:15:18 pm
If you now understand that there are two different ESD tests, one with the piezo grill ignitor and one with the new gun, what are you considering the "sparker test"?

Either will do, but I think you should keep doing with the grill igniter simply because it's become a de-facto yardstick. It's difficult to compare new/old results if we switch to something else.

Do those igniters wear out with time? It might be good to measure the sparks and make sure it's holding up, producing sparks just like the first day.

There's a fair difference between the two PCBs you show.

They've moved the buzzer and a few components around, yes.

When you really zapped the AN8002 the major trace damage happened around the area of the buzzer. Maybe they moved the buzzer away to improve that area of the PCB.  :popcorn:

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333138;image)

Regardless, the thing that failed first on that meter was the transistor clamp - nothing to do with PCB spacing or layout. If the transistors in the AN8008 are the same then I'd guess it will fail in the same way.

Of my sample of two grill starters, there is a WIDE variance!! And yes I believe the output changes with time.   I have a starter that looks very similar to this one that is new and it puts out a much larger spark.   The one I use for testing actually came from a old grill I scrapped.  The spring tension is a fair amount less than the new one. 

It only really gets used for the meters and I have checked the output a couple of times during the course of all this testing and it appeared to be the same. 

I have changed the test methods before as I  find better ways to run them.   

When I "zapped" the AN8002, it was the higher energy generator that caused the damage you mention.  I don't record any of this testing in the spreadsheet.  It's more an FYI than anything.   

Because the PTC and clamp are located pretty much in the worst possible location setting up a loop that runs more than half the length of the board, it's really hard to say how changing the layout will effect it.  The part placement and layout are VERY important when you start pumping several amps through the board in sub ns.       

You may feel the clamp would take the initial hit and I would tend to agree with that for the slower rise time transients.  The grill starter transient is pretty much over in 10ns.  The rise time on the other generator is around 1us.   It matters! 

I would really have no way of knowing what failed first on the 8002.  You can guess it's the clamps but I can't say that for sure.  Again, many thing will play into this including the layout. 

I would say if I had been able to replace the clamps or even just remove them and get the meter functional again, you would be correct.  That was not the case.   

Where are you sending the $10 if the 8008 fails the gun?  I think if it fails you should have to send Dave $20 to cover his cost of the 8008.   :-DD   
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 19, 2017, 01:30:21 pm

I am more impressed by Lightages belief in "the power of CAT-markings".  As you can see, he finds this meter to be suitable for beginners because it has no fake CAT-rating.

 :popcorn: :popcorn: :popcorn:

More putting words in other's mouths, troll.........

You know trolling here, lying about what people say or what their intent is, are reasons for discipline here. Keep it up.....

Quote
If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments.

It does seem to me that is what you were suggesting from your comment above.   



Beginner:
Look at this cool little multimeter I just got from China. It  has no CAT-ratings, so I will only use it for my arduino.

I am thoroughly impressed with the Norwegian "beginners", who all know what a CAT rating is.
(And who actively look for a CAT rating, notice its absence, and draw the right conclusions.)  ::)

Come on, a beginner is just as likely to poke at a wall outlet with that unrated meter as with an AN8008. And just as unlikely to electrocute himself doing it.


When UI was a beginner, we did not have these fancy meters to poke at the wall socket.  At best we had scissors and not the ones with plastic handles.    :-DD   While I did not fall pry to that, a classmate did.  We were maybe 5 then. :-DD :-DD  I plugged a chopped off line cord that I had stripped the ends in and then touched the wires, catching my bed on fire. :-DD  The wonders of electricity to a small child..  :-DD     
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 19, 2017, 01:35:05 pm
Harbor Freight also gives away these beauties. The convenient on/off switch means the selector can literally be in any position when junior connects the probes.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=333175;image)

I guess anyone, not just Jr, could have the selector literally in any position when we connect the probes to the meter or to the target. 

If I pick one of these up and it fails on the new gun, would you send Dave another $20?    I need some incentive...  :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 02:13:09 pm
is everyone that calls you out on anything a 'troll' ?
I welcome discussion, but with points being made. Not with straw men arguments. I believe that meters should be not be rated falsely. That is all I have asserted in this thread. Trying to make it look like I have been trying assert anything differently is a straw man argument, or trolling, or completely idiocy.

Tronde delivers the goods backing up what he types,

why is he a troll and you're not ?

When have I misrepresented anything anyone has said? He has.

It borders on forum slander  :--

 :-DD "forum slander"!!!! :-DD
Really, I state my opinion and point of view and have it twisted to something I didn't say and defend myself and I am the one "slandering"?  :palm:

Edited for typo
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 02:19:12 pm
I will clarify my statement "If it has no claim of safety, it looks like a cool little meter for the beginning hobbyist to have for his/her low energy experiments. That is, if can be reliable for such a cheap price."

In the context of the concern I have for mislabeled CAT ratings, the fact that is not going to cause a newbie to use it n the wrong circumstance because it claims to be safer than it is, it is more suitable for a newbie who at least knows that CAT ratings indicate it is safe.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 02:20:34 pm
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333142)
What happened? Hopefully no hurt feelings were involved between the parties...

I explained it in this thread:
http://www.eevblog.com/forum/chat/announcement-i-am-not-a-brymen-distriubotr-anymore/msg1195867/#msg1195867 (http://www.eevblog.com/forum/chat/announcement-i-am-not-a-brymen-distriubotr-anymore/msg1195867/#msg1195867)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 19, 2017, 03:13:26 pm
I agree Wilfred. When a person adds  :popcorn: to their post, it is a clear declaration of the intent to provoke, or troll.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Gary.M on July 19, 2017, 04:52:14 pm
I agree Wilfred. When a person adds  :popcorn: to their post, it is a clear declaration of the intent to provoke, or troll.
Fungus is the king of popcorn here. With the frequency that he reaches for it he must have an expanding waistline.

Sent from my x600 using Tapatalk

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 19, 2017, 05:17:20 pm
...I believe that meters should be be rated falsely. That is all I have asserted in this thread.

Why should they be rated falsely?

Isn't that fraudulent and DANGEROUS for those deceived? 

BTW: since when did munching on maccas / popcorn / chips  and sipping cola /KoolAid    (example >  :popcorn: )    make one a troll candidate ?   

going by your incinuation alone, the forum must be crawling with them...       :scared:

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 19, 2017, 05:49:29 pm
since when did munching on maccas and sipping cola    (example >  :popcorn: )    make one a troll candidate ?   

I agree that the "popcorn" icon has that trolling connotation. To me, it says: "I'll sit back now and enjoy the show/fight (which I hope to incite with this post)".

I have been wondering before whether this forum would be an even better place if some of the emoticons were no longer offered. The popcorn-eater is one of them. I also find that the :-DD and :palm: can be quite offending, when they are used to comment on another member's posts. You would probably use neither gesture in a face-to-face dialog, at least not in a civilized one. But of course those emoticons have non-offending uses, when posted in reaction to a genuine joke, your own error, or some ridiculous/stupid proceedings outside the forum.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 06:25:11 pm
Harbor Freight also gives away these beauties. The convenient on/off switch means the selector can literally be in any position when junior connects the probes.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=333175;image)

I guess anyone, not just Jr, could have the selector literally in any position when we connect the probes to the meter or to the target. 

As far as multimeter safety sins go, the "convenient on/off switch" is one of the worst. Fake CAT ratings pale by comparison.

Just think of the children!

If I pick one of these up and it fails on the new gun, would you send Dave another $20?    I need some incentive...  :-DD

Nope.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on July 19, 2017, 06:29:45 pm
I know this is another $25 meter ($24.99 actually) but this coming Saturday, ALDI is offering this one.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333267;image)

Wonder what it would be like inside....?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Muttley Snickers on July 19, 2017, 06:40:25 pm
Be sure to keep the purchase receipt in a safe place, you will need it for the return process.   :o ::) :-BROKE
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 06:41:35 pm
When I "zapped" the AN8002, it was the higher energy generator that caused the damage you mention.  I don't record any of this testing in the spreadsheet.  It's more an FYI than anything.   

Yes. The meter had already failed (one of the clamp transistors exploded), you were unsatisfied with that result and felt the need for some fireworks so you turned up the power and switched it to an amps range. We all have days like that, it's nothing to be ashamed of.

Where are you sending the $10 if the 8008 fails the gun?
To any person who sends me $10 if it doesn't.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 19, 2017, 06:43:20 pm
I know this is another $25 meter ($24.99 actually) but this coming Saturday, ALDI is offering this one.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333267;image)

Wonder what it would be like inside....?

I doubt anyone will see it on Saturday,

Fluke are sending their suits to Aldi Inc. tomorrow morning  >:( >:( >:( >:( >:( >:(



You might see a truckload of crushed ones at a local tip next Saturday  ;D

 
 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 06:43:49 pm
I agree Wilfred. When a person adds  :popcorn: to their post, it is a clear declaration of the intent to provoke, or troll.
Fungus is the king of popcorn here. With the frequency that he reaches for it he must have an expanding waistline.

But in my own mind I lean more towards devil's advocate than troll.  :popcorn:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 08:38:04 pm
I doubt anyone will see it on Saturday,

Fluke are sending their suits to Aldi Inc. tomorrow morning  >:( >:( >:( >:( >:( >:(

You might see a truckload of crushed ones at a local tip next Saturday  ;D

I'm sure they're plenty angry, but ... this is Europe.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 19, 2017, 08:41:24 pm
I have been wondering before whether this forum would be an even better place if some of the emoticons were no longer offered. The popcorn-eater is one of them. I also find that the :-DD and :palm: can be quite offending, when they are used to comment on another member's posts.

To be 100% fair: They mainly get used because there's no middle-finger icon.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on July 19, 2017, 09:00:56 pm
Aldi = € 14,99
I hope the 8008 is better, else i payed 1 euro to much.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 19, 2017, 09:18:09 pm

To be 100% fair: They mainly get used because there's no middle-finger icon.

 :-DD

I'll take that as a "good" use of the laughing-myself-silly icon, rather than a "middle finger" use...  ;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Lightages on July 20, 2017, 12:56:14 am
...I believe that meters should be be rated falsely. That is all I have asserted in this thread.

Why should they be rated falsely?


Typo corrected.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 20, 2017, 01:10:54 am
So, some kind of testing (even not independent) with clearly stated results would be great. I guess it would increase the price for the same meter however.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 20, 2017, 01:18:38 am
Seems to me that Fluke have created a monster with their safety advertising. All the cases I have read about where some person has been injured or killed by a flash over while using a test meter have been using a Fluke hand held meter, in my opinion and its is just mine it is not a good idea to attempt to test a high energy source with a meter in your hand, it is asking for trouble even with HRC fuses and blast shields in the meter the leads could still melt. Recently we had a power pole replaced and a new meter fitted, the engineers doing the work did not use a hand held Fluke meter they used a Megger/AVO meter which was of a size that precluded holding it in the hand, further they attached the leads with clips neutral first then live then turned the meter on. When testing the 33 KV side of the transformer they had 20 foot fiberglass poles on which the test meter.
Any of these meters that go to a thousand volts are good enough to test things like the HT on most tube amp's etc where the currents are low but even low voltages can be trouble when currents are high, when I was around 13 I connected an AVO meter to a single cell lead acid battery set on amp's range the trip blew but not before the leads were smoking hot and burnt me
But the real thing that everyone is forgetting is that it is not right to falsely make claims about a product you are selling and certainly here in the UK would be liable under the trade description acts.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 02:23:42 am
Seems to me that Fluke have created a monster with their safety advertising. All the cases I have read about where some person has been injured or killed by a flash over while using a test meter have been using a Fluke hand held meter

Maybe the death toll would be even higher if they weren't using Flukes.  :-//

Or maybe you only read about idiots who think owning a yellow meter allows them to ignore safety protocols.

it is not a good idea to attempt to test a high energy source with a meter in your hand, it is asking for trouble even with HRC fuses and blast shields in the meter the leads could still melt.

That's why Fluke adverts look like this:

(http://media.fluke.com/images/117-14a-600x402.jpg)


And why shutterstock looks like this:

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333414;image)

Yin + Yang = harmony in the world.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 20, 2017, 02:40:17 am
I know this is another $25 meter ($24.99 actually) but this coming Saturday, ALDI is offering this one.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333267;image)

Wonder what it would be like inside....?
They don't give much information, but from what I can see, I will not be rushing to Aldi Saturday. morning. Four battery testing ranges. Transistor Hfe testing range. No mention of RMS. I think it is a cheap home handyman's multimeter. Couldn't see anything that might be interesting.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 20, 2017, 03:11:40 am
When I "zapped" the AN8002, it was the higher energy generator that caused the damage you mention.  I don't record any of this testing in the spreadsheet.  It's more an FYI than anything.   

Yes. The meter had already failed (one of the clamp transistors exploded), you were unsatisfied with that result and felt the need for some fireworks so you turned up the power and switched it to an amps range. We all have days like that, it's nothing to be ashamed of.

Where are you sending the $10 if the 8008 fails the gun?
To any person who sends me $10 if it doesn't.

Meter was damaged at the 3KV but the DCV function still worked.  I took the meter apart to see if it was a simple repair.  At that point the clamp was still fine.  The breakdown appeared to be in the selector switch.   The board does not have a lot on it and some of the functions were not showing the proper mode.  Conclusion, dead controller IC. 

If I could have repaired it, I would have stopped the testing and used it for another reference meter.  This is what happens with most of the repairable ones, or in the case of Dave's pre-production 121GW or the UNI-T 181A, I attempt to determine why they were damaged and see if they could be hardened.   Then I run them again.  In the case of the 121GW, it was damaged a second time but I got lucky and was able to repair it a second time and added one more TVS.  I then tested it again and it survived at the 6 and change KV level where I stopped testing. 

I ended up putting the meter back together and turned the generator up to max.  This damages it to where it no longer powers up. 

As I have previously explained, the 1/2 cycle simulator requires the low energy generator to work.  So the criteria is the meter is non-repairable and will break over at less than 5KV.   I applied one more transient with the lower energy generator to make sure it would break down in the volts mode.  I then gave it one transient off the 1/2 cycle in volts mode.  I switched the meter to mA and gave it one more cycle.  Then I took the meter back apart.  This is where you first see the extensive damage.   

I then give it one more transient with the cover off using the 1/2 cycle generator. 

I don't think I ever tried the Amps side.   I still have the meter sitting in the scrap box to recycle but I stole the shunt out of it when I ran all of them.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 20, 2017, 03:19:11 am
Where are you sending the $10 if the 8008 fails the gun?
To any person who sends me $10 if it doesn't.

If anyone would care to take Fungus up on his bet, I would be willing to run the meter.  I can't take the bet as if it does get damaged, someone may claim it was rigged.  It's also too far for me to go to meet up for a beer.  :-DD 
   
We could even run the grill ignitor first, so you could do a double down if you wanted.  :-DD   

Not sure if Fungus would take more than one bet.  Wouldn't hurt to ask if your all in the same area.  Seems like a good reason to meet up.     
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 20, 2017, 03:25:02 am
And why shutterstock looks like this:
[stock-photo-young-adult-electrician-builder-engineer-screwing-equipment-in-fuse-box-155918309.jpg]

Hey, he is even wearing a head torch, in case he blows up the switchboard and the lights go off.
Doesn't that count as safety precaution?   ::)


Edit: Also, according to the picture title, he is not measuring anything at all but "screwing the equipment"...  :palm:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 03:31:25 am
I then gave it one transient off the 1/2 cycle in volts mode.  I switched the meter to mA and gave it one more cycle. 

Yep, you're right. I watched it again and the transistors blew after you zapped in in mA mode.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 20, 2017, 03:38:57 am
And why shutterstock looks like this:
[stock-photo-young-adult-electrician-builder-engineer-screwing-equipment-in-fuse-box-155918309.jpg]

Hey, he is even wearing a head torch, in case he blows up the switchboard and the lights go off.
Doesn't that count as safety precaution?   ::)


Edit: Also, according to the picture title, he is not measuring anything at all but "screwing the equipment"...  :palm:

You can't do that with a fluke dmm, can you?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 03:46:36 am
Edit: Also, according to the picture title, he is not measuring anything at all but "screwing the equipment"...  :palm:

The screw appears to be 'hot', but ... luckily for him he was using a safety screwdriver.  :)

Unlike the guy below.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 03:54:50 am
Edit: Also, according to the picture title, he is not measuring anything at all but "screwing the equipment"...  :palm:
You can't do that with a fluke dmm, can you?

I checked their 'accessories' page but couldn't find anything. Just a load of overpriced cables and meter pouches.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 20, 2017, 03:59:23 am
What would an electrician even use to screw those things? After checking the power.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 04:02:00 am
If anyone would care to take Fungus up on his bet, I would be willing to run the meter.  I can't take the bet as if it does get damaged, someone may claim it was rigged.  It's also too far for me to go to meet up for a beer.  :-DD 
   
We could even run the grill ignitor first, so you could do a double down if you wanted.  :-DD   

Tell you what: I'll up my bet to the price of a meter. If anybody thinks an AN8008 won't survive the grill igniter I'll get a meter shipped to joe and you can send me the purchase price via paypal if it lives.

Not sure if Fungus would take more than one bet.
Nope. Only one meter. First come, first served.

Wouldn't hurt to ask if your all in the same area.  Seems like a good reason to meet up.     

I'm in Spain. If anybody else lives in Valencia you're welcome to come along to my Arduino club this Friday. PM for details.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 04:03:54 am
What would an electrician even use to screw those things? After checking the power.

This:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 20, 2017, 06:29:47 am
With the Fluke photo the man is holding a probe in each hand, so the meter blows up it's not in his hand the fuse go's the blast shields hold and what? the energy looking for somewhere to go jumps the probes to each of his hands, it's still not safe. As I stated in my earlier post the true professionals on power line's or other potential high energy use clip on probes on at least one end. And don't use hand held meters of any make.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 20, 2017, 08:28:47 am
With the Fluke photo the man is holding a probe in each hand, so the meter blows up it's not in his hand the fuse go's the blast shields hold and what? the energy looking for somewhere to go jumps the probes to each of his hands, it's still not safe. As I stated in my earlier post the true professionals on power line's or other potential high energy use clip on probes on at least one end. And don't use hand held meters of any make.
I think it may also be true that they would not be using a multimeter either, at the very least they would be using a dedicated voltmeter in order to minimise the chances of a high energy inrush surge to the instrument?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 04:02:58 pm
With the Fluke photo the man is holding a probe in each hand, so the meter blows up...

Why would it blow up? What mechanism?

A Fluke 117 (the meter in that photo)  is rated/tested for a CAT III 600V environment. That's a fairly precise specification about where it can be used safely.

...the fuse go's the blast shields hold and what?

The fuse won't go, because the meter isn't in a current measurement mode.

As I stated in my earlier post the true professionals on power line's or other potential high energy use clip on probes on at least one end. And don't use hand held meters of any make.

A "professional" will asses the environment and use an appropriate method.

If it's a CAT III 600V environment then a Fluke 117 is appropriate.

If it's a CAT IV 600V environment then a Fluke 117 isn't appropriate and you have to use something else.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 04:15:36 pm
I think it may also be true that they would not be using a multimeter either, at the very least they would be using a dedicated voltmeter in order to minimise the chances of a high energy inrush surge to the instrument?

Yes. As Dave says, if he were an electrician he'd buy a meter with no current measurement ranges.

(ie. no fuses inside the meter, none!)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 20, 2017, 05:38:13 pm
I think it may also be true that they would not be using a multimeter either, at the very least they would be using a dedicated voltmeter in order to minimise the chances of a high energy inrush surge to the instrument?

Yes. As Dave says, if he were an electrician he'd buy a meter with no current measurement ranges.

(ie. no fuses inside the meter, none!)
Is that not what I said? when testing high energy circuits they did not use a multimeter they used a specialist piece of equipment, It was not just a voltmeter it tested things like the earth resistance and current as well as trip time and current in breakers some of the functions simultaneously and pretty much with hands off and out of the way. The Fluke adverts give the impression that it is OK to use a multimeter in such conditions and maybe Fluke meters are CAT rated correctly but they still wont protect you when a mistake is made or a very large surge takes place. I have not gone throgh the Fluke catalogue but I would expect they or one of the subsidiaries manufactures such specialist equipment. If you think about the Fluke foto. it could well be safer for the man shown to be holding the meter in one hand.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 06:45:03 pm
Is that not what I said?

I don't know. You didn't say what "high energy circuit" was being measured. How many volts, what's the line impedance?

There are plenty of "high energy circuits" that a handheld multimeter is suitable for. eg. Anything classed as CAT IV is "high energy" and CAT IV handheld multimeters are real things.

The Fluke adverts give the impression that it is OK to use a multimeter in such conditions

The Fluke adverts don't say anything about what the 'conditions' in that photo are but I'm sure Fluke lawyers have approved it for publication on their web site. It will therefore be correct usage of a Fluke multimeter.

The photo shows somebody measuring 230V using a CAT III 600V Fluke multimeter. It looks like a CAT IV environment but that isn't stated. Even if it is a CAT IV environment I believe a CAT III 600V meter can be derated to CAT IV 300V so it's acceptable use (let the experts correct me if I'm wrong here).

For reference, the CAT rating chart is this:
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333687;image)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 20, 2017, 07:16:24 pm
The Fluke 117 won't even read after about 660? volts anyway I think

You get 'OL' 


which really means 'LOL'  buy a post GSM pre MIC?   87V    ;D 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 07:35:40 pm
The Fluke 117 won't even read after about 660? volts anyway I think

So?

You get 'OL' 

which really means 'LOL'  buy a post GSM pre MIC?   87V    ;D

Get some sleep. It looks like you need it.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Electro Detective on July 20, 2017, 08:30:47 pm
The Fluke 117 won't even read after about 660? volts anyway I think

So?

You get 'OL' 

which really means 'LOL'  buy a post GSM pre MIC?   87V    ;D

Get some sleep. It looks like you need it.

Speak for yourself bub, you seem to be a permanent 24/7 fixture here playing bossy boots every chance you get 
and popcorn bait anyone you please without hindrance or criticism aka   >>>  :popcorn: :popcorn: :popcorn:

Do you own a 117 and or 87V ?

I do, and know their limitations

There's a reason the Fluke 117 exists, it fits a low voltage price point that suits electricians and users that don't need 87 features

Do some homework to understand why Fluke would design the 117 series so they won't read past 660v, and why an 87V does,
as well as many poorly made meters on the market that shouldn't, 
instead of advising others to "get some sleep "


Don't forget to click "Report to moderator"   and get some troll calling in,

before you eventually "get some sleep "   :clap:



Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 20, 2017, 09:08:32 pm
Great deal on the Chauvin Arnoux Metrix MTX 3281-BT I mentioned earlier, new in box at only £125 ! http://www.ebay.com/itm/263062827260 (http://www.ebay.com/itm/263062827260)

They only ship to the UK  :(
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 09:25:01 pm
There's a reason the Fluke 117 exists, it fits a low voltage price point that suits electricians and users that don't need 87 features

"CAT III 600V" meters exist because that's a working voltage suited to three-phase industrial power systems all around the world. It's a minimum requirement. It's nothing to do with electricians, price points or features.

You can also use CAT III 600V meters to work on 240V mains distribution panels.

PS: Fluke makes several CAT III 600V meters which are cheaper than the 117.

"which really means 'LOL' buy a post GSM pre MIC? 87V"

I have no idea what you're talking about but I don't see why a 600V limit is "LOL" worthy. It's a sensible design choice based on real-world needs (see above).

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 20, 2017, 09:57:09 pm
which really means 'LOL'  buy a post GSM pre MIC?   87V    ;D

I may be a bit thick here, but would appreciate an explanation of LOL, GSM and MIC in this context.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 20, 2017, 09:58:01 pm
I've now had three Aliexpress companies that sell the AN8008 (or their own branded one) and wanting me to promote their store  ::)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 20, 2017, 10:34:32 pm
Tell you what: I'll up my bet to the price of a meter. If anybody thinks an AN8008 won't survive the grill igniter I'll get a meter shipped to joe and you can send me the purchase price via paypal if it lives.

I appreciate the gesture.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 20, 2017, 10:52:16 pm
I've now had three Aliexpress companies that sell the AN8008 (or their own branded one) and wanting me to promote their store  ::)

You mean they want you to put a link to their store in the video?

What sort of $$$ were they offering?  >:D

If you're not going to take them up on the offer than maybe you could post the (anonymized) messages here for LOLs! (or make a blab)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 21, 2017, 02:26:34 am
Great deal on the Chauvin Arnoux Metrix MTX 3281-BT I mentioned earlier, new in box at only £125 ! http://www.ebay.com/itm/263062827260 (http://www.ebay.com/itm/263062827260)

They only ship to the UK  :(
Hmm I wonder why this is now a discontinued model, anything to do with it being a clam shell design with its inherent weak link, that ribbon cable at all????
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: TheAmmoniacal on July 21, 2017, 02:37:10 am
Great deal on the Chauvin Arnoux Metrix MTX 3281-BT I mentioned earlier, new in box at only £125 ! http://www.ebay.com/itm/263062827260 (http://www.ebay.com/itm/263062827260)

They only ship to the UK  :(
Hmm I wonder why this is now a discontinued model, anything to do with it being a clam shell design with its inherent weak link, that ribbon cable at all????

Hard to say why they have discontinued that design, forward it to me so I can have a look  8) I'll pay.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 21, 2017, 02:52:02 am
Sorry to repeat, but... I was just about to delete that image of the young electrician from my disk when I accidentally zoomed in on it.

The full comedic value was revealed to me, I had to share.

Just look at the size of the copper bars leading out of that monster circuit breaker he's poking at with his little neon screwdriver. How many amps?? The mind boggles. Looks like it would take a whole team of electricians just to move that switch. :-DD

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333767;image)

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on July 21, 2017, 03:09:45 am
That's a ridiculous photo!

No employer would allow you to even open the door on an energized panel, let alone no PPE like eye protection, gloves.
Then there's the $1 electrical tester with no return wire? How does it glow? From the dumbness lol  :palm:
Photoshopped busbars?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 21, 2017, 03:25:58 am
That's a ridiculous photo!

No employer would allow you to even open the door on an energized panel, let alone no PPE like eye protection, gloves.
Then there's the $1 electrical tester with no return wire? How does it glow? From the dumbness lol  :palm:

It's the gift that keeps on giving: If you reverse-GIS it you find it's used on pages and pages of schools for electricians (https://encrypted.google.com/search?tbs=sbi:AMhZZiukKx2GgDoOdkQPNhRyYYQxSd1B2LasBEz1yfyYNQdHRCrqrZSOmXFwCh0beXf_1aEQncMjjLEK5VXftmNFfOGwNodyc1xW93U8RkoIzviwoijXax3On6QpizeL758Zs3jLtO3wVYTm3_1q5RYsPN3jZ47Ma0oCU2IoX1BcHYnmcVQK4kryQvTh12tTIC3FNmAq3E2spZ--HUxozzXr-JOjYDkxJjXYf9WJDGM2168tAxnEUAxzRV5hQpsxSTr4Trt-22dGTG_1us3MmHz_1Y70tY6iMp_1Hi2ZSV09xU7WEkq3az5s8oWmFzAGoxgtOn7M1Hm3rwfkQzXLi6SWZoQv933erTD68yg&hl=en).

Another gem:   :-DD
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333780;image) (http://kbcomplete.com/breaker-panel-repair-replacement/)


Photoshopped busbars?

Nope, there's lots of different angles of him poking at different parts of the panel.

https://www.shutterstock.com/cs/image-photo/electrician-works-electric-meter-tester-fuse-359798642 (https://www.shutterstock.com/cs/image-photo/electrician-works-electric-meter-tester-fuse-359798642)

At least he turns his baseball cap around when he's working.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 21, 2017, 03:30:43 am
The tester screwdriver doesn't need a return wire. Your body is a capacitor of about 150pF. The current from the mains to your body capacitance is enough to light the neon lamp.  The thing that makes it safe is the $0.001 Chinese series resistor.  What could go wrong with that?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 21, 2017, 04:23:50 am
That's a ridiculous photo!

No employer would allow you to even open the door on an energized panel, let alone no PPE like eye protection, gloves.
Then there's the $1 electrical tester with no return wire? How does it glow? From the dumbness lol  :palm:

It's the gift that keeps on giving: If you reverse-GIS it you find it's used on pages and pages of schools for electricians (https://encrypted.google.com/search?tbs=sbi:AMhZZiukKx2GgDoOdkQPNhRyYYQxSd1B2LasBEz1yfyYNQdHRCrqrZSOmXFwCh0beXf_1aEQncMjjLEK5VXftmNFfOGwNodyc1xW93U8RkoIzviwoijXax3On6QpizeL758Zs3jLtO3wVYTm3_1q5RYsPN3jZ47Ma0oCU2IoX1BcHYnmcVQK4kryQvTh12tTIC3FNmAq3E2spZ--HUxozzXr-JOjYDkxJjXYf9WJDGM2168tAxnEUAxzRV5hQpsxSTr4Trt-22dGTG_1us3MmHz_1Y70tY6iMp_1Hi2ZSV09xU7WEkq3az5s8oWmFzAGoxgtOn7M1Hm3rwfkQzXLi6SWZoQv933erTD68yg&hl=en).

Another gem:   :-DD
(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333780;image) (http://kbcomplete.com/breaker-panel-repair-replacement/)


Photoshopped busbars?

Nope, there's lots of different angles of him poking at different parts of the panel.

https://www.shutterstock.com/cs/image-photo/electrician-works-electric-meter-tester-fuse-359798642 (https://www.shutterstock.com/cs/image-photo/electrician-works-electric-meter-tester-fuse-359798642)

At least he turns his baseball cap around when he's working.
If he's standing on the regulation rubber floor mat then that neon should not be glowing surely??
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 21, 2017, 04:47:01 am
If he's standing on the regulation rubber floor mat then that neon should not be glowing surely??

It's not about conductivity, it's about capacitance.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 21, 2017, 05:03:16 am
If he's standing on the regulation rubber floor mat then that neon should not be glowing surely??

It's not about conductivity, it's about capacitance.
There has to be a return path somewhere for the albeit, small current, for the neon to glow.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: deflicted on July 21, 2017, 05:11:44 am
My 4 year old son has a head-lamp exactly like the one in that photo. It's absolute junk, every bit as flimsy and cheap as you'd imagine, not even fit to be a child's toy. Plus the illumination it provides, even with fresh batteries, is terrible. If you used that to light up an electrical panel in a dark place, you'd barely be able to tell the black wires from the red wires. If that.

They might as well have shown him wearing one of these:

(https://i.ebayimg.com/images/g/P8sAAOSwQPlV-cDr/s-l500.jpg)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 21, 2017, 05:18:34 am
There has to be a return path somewhere for the albeit, small current, for the neon to glow.

Yes, but the return path can be via capacitive coupling to ground, rather than resistive.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: deflicted on July 21, 2017, 05:25:15 am
That's a ridiculous photo!

No employer would allow you to even open the door on an energized panel, let alone no PPE like eye protection, gloves.
Then there's the $1 electrical tester with no return wire? How does it glow? From the dumbness lol  :palm:
Photoshopped busbars?

Just out of curiosity, how would someone troubleshoot a panel like that if they're not allowed to open the door with it energized? Do they just have to dismantle the whole thing and bench test each component separately? Or maybe turn it off, hook up test gear, instrumentation, etc, then turn it back on and monitor from a distance?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on July 21, 2017, 06:22:48 am
This panel has plenty of non touch-safe components, kinda home-made looking from 19" rack stuff

Qualified personnel (electrician+PPE) could make measurements on a live panel, but dangerous depending on the voltage class. It's frowned upon because always an idiot nearby and love that door swinging into you.
Electrician has 4kV motor control panel open, his equipment cart rolls and bumps into it and massive arc-flash explosion. Quite spectacular.
Properly, there is a lock-out procedure where you get a plant/site permit and pad-lock the disconnect off.


I don't think body-capacitance is enough for a neon-lamp that bright, 600VAC 60Hz 100pF I get Xc=26MEG and 19uA.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 21, 2017, 06:55:51 am
Qualified personnel (electrician+PPE) could make measurements on a live panel, but dangerous depending on the voltage class. It's frowned upon

If you're wearing a hard hat and carrying a large yellow multimeter they might let you.

If you're wearing a baseball cap and carrying a neon screwdriver? Not so much.

Still, this was apparently taken in Russia so different standards apply. Want to take some pictures of the pretty wires and switches? Just give the guy with the keys some American cigarettes and a bottle of vodka.

I don't think body-capacitance is enough for a neon-lamp that bright, 600VAC 60Hz 100pF I get Xc=26MEG and 19uA.

Maybe $0.001 Chinese safety resistor was failing.

(and he was this >.< close to disappearing in a big blue flash)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Someone on July 21, 2017, 11:07:17 am
That's a ridiculous photo!

No employer would allow you to even open the door on an energized panel, let alone no PPE like eye protection, gloves.
Then there's the $1 electrical tester with no return wire? How does it glow? From the dumbness lol  :palm:
Photoshopped busbars?

Just out of curiosity, how would someone troubleshoot a panel like that if they're not allowed to open the door with it energized? Do they just have to dismantle the whole thing and bench test each component separately? Or maybe turn it off, hook up test gear, instrumentation, etc, then turn it back on and monitor from a distance?
Both of your suggestions are correct and ways that industrial electricians might debug such a panel, but there are also cases where they might measure or even work on it live. The work would be carefully planned by a group of people and not just opening it up then investigating ideas as they come up, then it would be done with 2-3 people present who are all suitably trained in electrical safety and first aid procedures.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on July 21, 2017, 11:28:01 am
I did notice he kept his fingers as far back as possible.  Well away from the shaft and tip.

That has to count for something.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 21, 2017, 11:37:02 am
Tell you what: I'll up my bet to the price of a meter. If anybody thinks an AN8008 won't survive the grill igniter I'll get a meter shipped to joe and you can send me the purchase price via paypal if it lives.
I appreciate the gesture.
It's on it's way. Maybe in a few weeks I can run it. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 21, 2017, 11:54:14 am
I don't think body-capacitance is enough for a neon-lamp that bright, 600VAC 60Hz 100pF I get Xc=26MEG and 19uA.
The glow is visible with just microamps of current. 19uA would be fairly bright. The voltage drop across the neon is something like 70V.

Someone probably did a bit of photoshopping in the photo to make it brighter.

Just did a test with one of these screwdrivers. At 240V AC 50Hz, the glow is very visible with 13uA. According to my calculations, my body must have been at about 160V AC and my body capacitance must be about 260pF!

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: jonovid on July 21, 2017, 12:01:50 pm
I have ordered it online, on the understanding that the AN8008 DMM is basic. but has some redeeming qualities for a hobbyist
working with low voltages like battery powered toys. grill igniters are not on the list.  ::)  also its not my only DMM on the bench.  reminds me, did Dave fix that piezo mosquito problem he had in his own branded DMM.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 21, 2017, 01:53:11 pm
I have ordered it online, on the understanding that the AN8008 DMM is basic. but has some redeeming qualities for a hobbyist
working with low voltages like battery powered toys. grill igniters are not on the list.  ::)  also its not my only DMM on the bench.  reminds me, did Dave fix that piezo mosquito problem he had in his own branded DMM.


The 235 I bought did not have the audio problem.  Just the connectors were not fitted very well. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: retiredcaps on July 21, 2017, 01:57:00 pm
Voltlog posted this video.  I haven't watched it yet, but I thought I would share.

http://www.youtube.com/watch?v=1UVXU4JvvtY (http://www.youtube.com/watch?v=1UVXU4JvvtY)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 21, 2017, 05:29:57 pm
That shutterstock photo is exactly that a Stock photo with a model posing with the neon screwdriver and a switch panel that is most likely standing on a bench, the neo light is the bit photo-shopped in. No doubt for the requisite fee you can have the photo for your own advertising without the water mark.
All the big power switch banks that I have seen cannot be opened with the power on due to mechanical interlocks, and I have seen a few big switch panels in my life as I used to build and service big gen sets at one time.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 21, 2017, 06:17:23 pm
I did notice he kept his fingers as far back as possible.  Well away from the shaft and tip.

That has to count for something.

Not in every shot.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333971;image)

The neon glow on his finger there looks very real to me.


Apparently the head torch works! They did some shots in the dark.

The darkness reveals some green LEDs on the breakers. Does green mean "OK!" or "safe to poke at"?

That shutterstock photo is exactly that a Stock photo with a model posing with the neon screwdriver and a switch panel that is most likely standing on a bench

Might be true if there were no photos of the surroundings (https://www.shutterstock.com/cs/image-photo/young-adult-electrician-builder-engineer-inspecting-163349519?src=dJD2fg9jxLOIQkE-RKea5A-1-52).

I don't think body-capacitance is enough for a neon-lamp that bright, 600VAC 60Hz 100pF I get Xc=26MEG and 19uA.
The glow is visible with just microamps of current. 19uA would be fairly bright. The voltage drop across the neon is something like 70V.

Someone probably did a bit of photoshopping in the photo to make it brighter.

This is Russia! Russia is famous for their neons, Nixie tubes, etc. IT stands to reason that their screwdrivers are brighter.


(How did we get from "$25 multimeter" to this?)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on July 21, 2017, 08:32:49 pm
I've now had three Aliexpress companies that sell the AN8008 (or their own branded one) and wanting me to promote their store  ::)
You mean they want you to put a link to their store in the video?
What sort of $$$ were they offering?  >:D

I don't care. I automatically turn down all sponsored or paid video review requests.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: cezar on July 22, 2017, 01:51:51 am
anyone got hands on this?
https://www.aliexpress.com/store/product/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/1490693_32819174795.html (https://www.aliexpress.com/store/product/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/1490693_32819174795.html)

it's only $10 more expensive (well... I know it's 40% more) but seems like much more capable.


Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 22, 2017, 01:56:57 am
anyone got hands on this?
https://www.aliexpress.com/store/product/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/1490693_32819174795.html (https://www.aliexpress.com/store/product/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/1490693_32819174795.html)

it's only $10 more expensive (well... I know it's 40% more) but seems like much more capable.

Looks amazing, specs are up there with a Fluke 87V. More meter than I'll ever need.


(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=334056;image)

I dunno though. The workmanship of the input jacks may be exquisite but the design's only "reasonable".  :o

(insert the pen smoothly but firm. Oh, baby).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 22, 2017, 02:12:23 am
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.
If the other specs are as credible, I'll pass on it...

EDIT: I see that they have photos of two slightly different meters in that product description. They seem to have added space for the extra "1" in a revised version.

(http://ae01.alicdn.com/kf/HTB18jZYSXXXXXXLaFXXxh4dFXXX6.jpeg)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 22, 2017, 02:14:13 am
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.
If the other specs are as credible, I'll pass on it...

I think I could get an AN8002 and an AN8008 for the same price and do more work than with one of those.

The only other thing I might need from a meter is safety. I'm betting that one doesn't have it, despite the CAT IV marking on the front.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 22, 2017, 03:41:26 am
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.
If the other specs are as credible, I'll pass on it...

I think I could get an AN8002 and an AN8008 for the same price and do more work than with one of those.

The only other thing I might need from a meter is safety. I'm betting that one doesn't have it, despite the CAT IV marking on the front.

Also, it comes with no USB connectivity? I think that there are meters with that option at that price range. Although, their specs might not match, but still, logging can be useful.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 22, 2017, 05:32:37 am
Also, it comes with no USB connectivity? I think that there are meters with that option at that price range. Although, their specs might not match, but still, logging can be useful.

Yeah, if you could get logging that might be useful.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on July 22, 2017, 05:36:34 am
There are many multimeters with the same DTM0660 chip as in Aneng AN8002 but with logging built in or TX pin bonded. However they are much larger in size except Victor VC-921.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: cjs on July 22, 2017, 11:39:16 am
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.

I'm pretty sure you're being sarcastic here, and ha ha, but just in case someone else doesn't get it:

Incorrect photos are not unusual. The meter is actually pretty similar in specs to the (in)famous UT61E (the most notable difference to my eye is that it lacks a 2 A current range), and there are a lot of pictures of the UT61E with the correct model name on the meter but showing the rather different display of the UT61A through D models. My guess would be that a lot of shops have a graphics guy to whom they hand photos to be cleaned up and they get "cleaned up" without much care as to which photos were actually used to assemble the final image.

In this case, looking at the images below taken from this store's link (https://www.aliexpress.com/store/product/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/1490693_32819174795.html), the first one I would guess is from a different, lower-count meter; note the lack of space for a "1" digit between the "AC" indication and the four digits and, much more damning, the lack of a secondary display or bar graph. The second image looks as if it's a correct display; there's only four digits but there is space for a presumably non-iluminated "1" digit at the left. And the third image of course shows that there is indeed a "1" digit there.

I always get nervous, though, when looking at shops displaying what is ostensibly the meter I'd be buying but with the wrong display. This guy (https://www.aliexpress.com/item/UNI-T-UT-61E-UT61E-22-000-count-AC-DC-bench-Modern-meter-Digital-Multimeter-Volt/1926170329.html) is $7 cheaper than this guy (https://www.aliexpress.com/item/UNI-T-UT-61E-Digital-Handheld-Mutimeter-Tester-DMM-AC-DC-Volt-Ohm-Frq/32404631948.html) for what is supposed to be, but doesn't look like, the same meter.

(And hey, since we're totally off topic at this point anyway, now that I've learned much about people feelings toward meter labeling, anybody want to discuss how the ZEAST 282 compares to the UT61E, besides the obvious lack of serial data output?)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MacMeter on July 22, 2017, 01:00:35 pm
Back on topic:
Searched the Internet, could not find a PDF manual for this "AN8008 True-RMS Digital Multimeter". Anyone know of a download link? Thanks!
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 22, 2017, 04:40:26 pm
Already posted by you here (http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/msg1262327/#msg1262327) (and has since been answered). Please do not post the same question multiple times. It makes people waste time answering a question that may already be answered and splits discussions. It is bad enough having two threads about the same meter; please do not make it worse.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 22, 2017, 07:46:13 pm
Maybe it's a good idea to combine the topics, or pick just one?
It's pretty difficult to keep track on both (and what is shared in both)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on July 22, 2017, 09:18:06 pm
That new movie measures nothing, they only talk about daves movie and say the same stuff, bad movie.
Someone making movie with measuring results please ?, oh wait, no one has that expensive calibration stuff.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 05:38:58 am
Harbor Freight also gives away these beauties. The convenient on/off switch means the selector can literally be in any position when junior connects the probes.

(http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/?action=dlattach;attach=333175;image)

I guess anyone, not just Jr, could have the selector literally in any position when we connect the probes to the meter or to the target. 

As far as multimeter safety sins go, the "convenient on/off switch" is one of the worst. Fake CAT ratings pale by comparison.

Just think of the children!

Under what conditions do you feel having a separate on/off switch makes a handheld multimeter less safe than one where the function is built into the rotary selector?

Do you feel the separate mechanical on/off switch is less safe than an electronic one? 

What about meter's that can be powered up by remote?

What about meters that go into sleep mode and you rotate the selector to wake them?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 23, 2017, 05:57:46 am
Not Fungus, but my $0.02.

Under what conditions do you feel having a separate on/off switch makes a handheld multimeter less safe than one where the function is built into the rotary selector?
I do not think it is a big deal. The meter should be safe regardless of the switch and leads configurations. So powering on a meter with the switch set to current should not be a safety issue. That this is almost certainly not the case with this particular meter is a different issue.

Of course it can blow an (expensive) fuse or trip a breaker, shutting down a mains circuit. But those are not safety issues (unless there was a pre-existing one like a locked door that cannot be opened without electricity). I do not think it is an amazing design in combination with the shared current jacks. But I remember bench meters that used ganged switches for function switch (so it would be persistent across power off). They had a separate power button. And some had a shared V/mA socket. Never had any problems with that.

Do you feel the separate mechanical on/off switch is less safe than an electronic one? 
Since power on/off on a DMM will not usually affect safety and function selection or voltage at/current through the test leads, I do not think this matters at all. Meters that use soft switching for functions (e.g. any modern bench meter) will usually default to a high impedance (e.g. DCV) state on power on.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MacMeter on July 23, 2017, 06:26:53 am
Already posted by you here (http://www.eevblog.com/forum/testgear/an8008-us-$19-10000count-1uv-0-01ua-0-01ohm-resolution-meter/msg1262327/#msg1262327) (and has since been answered). Please do not post the same question multiple times. It makes people waste time answering a question that may already be answered and splits discussions. It is bad enough having two threads about the same meter; please do not make it worse.

Normally a good suggestion. Unfortunately, not everyone follows every thread on the same subject. Therefore it's not possible to know what members may be able to help, if they are not in all the "sister" threads that may exist. Combining threads is usually the proper solution.

With some of the crazy, and OFF TOPIC posts, I don't see my "double" request post for pertinent information all that problematic. But thanks again for the link to the manual.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 07:04:15 am
Not Fungus, but my $0.02.

Under what conditions do you feel having a separate on/off switch makes a handheld multimeter less safe than one where the function is built into the rotary selector?
I do not think it is a big deal. The meter should be safe regardless of the switch and leads configurations. So powering on a meter with the switch set to current should not be a safety issue. That this is almost certainly not the case with this particular meter is a different issue.

Of course it can blow an (expensive) fuse or trip a breaker, shutting down a mains circuit. But those are not safety issues (unless there was a pre-existing one like a locked door that cannot be opened without electricity). I do not think it is an amazing design in combination with the shared current jacks. But I remember bench meters that used ganged switches for function switch (so it would be persistent across power off). They had a separate power button. And some had a shared V/mA socket. Never had any problems with that.

Do you feel the separate mechanical on/off switch is less safe than an electronic one? 
Since power on/off on a DMM will not usually affect safety and function selection or voltage at/current through the test leads, I do not think this matters at all. Meters that use soft switching for functions (e.g. any modern bench meter) will usually default to a high impedance (e.g. DCV) state on power on.

I figured Fungus brought  it up and could explain his reasoning.  I appreciate the input if others want to chime in on this as well. 
 
I've never seen a meter where the function or on/off switch has anything to do with the high current inputs.  If you have the leads connected and you attach across 2 phases of your 480 bus, at best the HRC fuse will go.  Worst, well for the meter Fungus refers to, there is no fuse.   Still, is has nothing to do with how the on/off is implemented in the HF meter or any other that I am aware of. 

Based on his initial post
Quote
The convenient on/off switch means the selector can literally be in any position when junior connects the probes.
  it seems this is concern but I can't come up with a case were it would increase your risk. 

Of the meters that I have remaining, the ones with a separate on/off switch are:

CEN-TECH  90899, mechanical  (basically the meter Fungus refers to)
UNI-T UT181A, electronic
Gossen Metrawatt Ultra, electronic
Fluke 97 scopemeter, electronic

The Gossen is an interesting case.  Forgetting that the relays can change their states from a simple magnetic hanger causing the meter to display very low voltages when high voltages present, the reason for the relays is to be able to remotely control the meter.   If you were using the meter with the RF link enabled, the meters function can be changed by the remote.   I really like the CEM with it's RF link and have used it.  However, in every case I set the meter up then forget it.  I see no value in being able to change the function from an RF link and can see this adding risk.   Removing this feature would have solved the state change problem as well.   I never did hear anymore out of Gossen.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 23, 2017, 07:15:33 am
I figured Fungus brought  it up and could explain his reasoning.  I appreciate the input if others want to chime in on this as well. 

Short version: It increases the amount of diligence needed to operate it safely.

(as compared to a meter which has an "off" position and the high voltage ranges next to it)

The temptation will be to use it and simply switch it off. If you measure (eg.) current then switch off the leads will be in a low impedance position while it's sat waiting for next use.

Based on his initial post
Quote
The convenient on/off switch means the selector can literally be in any position when junior connects the probes.
  it seems this is concern but I can't come up with a case were it would increase your risk. 

I guess junior could also play with the dial on any meter before connecting the probes. Maybe it's not really much extra risk.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 07:23:16 am
The temptation will always to be to simply power it off when you finish using it instead of returning the selector to a safe position.

eg. After measuring current, the selector will be in an amps range. If you simply switch it off and the next reading is a power supply (or heaven forbid, mains AC) then that's where the selector will be when you connect the probes.

A meter that always forces you to move the selector to a safe position after use is much better IMHO. Extra points if the ranges next to the "OFF" position are the high voltage ranges.

Of course such a meter can be operated safely, but ... Harbor Freight giving away DT830B class meters with on/off switches seems dangerous to me.

I guess with most handheld meters with a shunt, that fact you turned it off and the function was left in the Amps is not the problem.  It's that you left the leads in the Amps.    If I understand, you would really like a meter than can only be turned off by the function switch and the meter has a shutter feature that forces you to install the leads into the non-current inputs in order to turn it off?   

Quote
The same argument can be leveled at meters with separate input jacks for current. You have to be diligent about swapping the leads back after every use. If you forget and your next reading is a power supply, then, pop!

I can imagine a meter with a shared 20A input and someone rotating the switch to the second off position past the Amps function with the meter still connected across the 480 bus..  Oh yea, and the meter has a glass fuse rated for 250 in there.... :-DD   

Personally, rather than adding more complexity with shutters and shared/unique current inputs, if it were mandated that all meters for CAT III and up could not have a shunt, I personally would be fine with it.  I'm sure most would not agree with me.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 23, 2017, 07:30:47 am
Personally, rather than adding more complexity with shutters and shared/unique current inputs, if it were mandated that all meters for CAT III and up could not have a shunt, I personally would be fine with it.  I'm sure most would not agree with me.

Those meters can have current clamps so where's the problem?  :popcorn:


Harbor Freight could also give away meters that only do volts and continuity. I'm sure that's 99% of what they're used for anyway.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on July 23, 2017, 07:33:58 am
I hate to bring up AN8008/ZT109 HV spacings here, but I took my AN8008 apart and it seems the rotary switch is the bottle neck?
Forget my grumblings about the fuses and poor PCB layout and fake 61010 claims.

The rotary switch PCB track spacing measures 1mm, and the wipers' spacing 0.60mm :o  so I imagine that's the limit.
I can't recall if joeqsmith has done a robustness test on this model, I think I saw the AN8002 test.





Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 23, 2017, 07:44:48 am
I hate to bring up AN8008/ZT109 HV spacings here, but I took my AN8008 apart and it seems the rotary switch is the bottle neck?
Forget my grumblings about the fuses and poor PCB layout and fake 61010 claims.

The rotary switch PCB track spacing measures 1mm, and the wipers' spacing 0.60mm :o  so I imagine that's the limit.
I can't recall if joeqsmith has done a robustness test on this model, I think I saw the AN8002 test.

Is anybody still imagining this is a 'safe' meter?  :-//

The AN8002 did better than a Fluke 87V in joe's tests, I imagine this one will be similar.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 07:49:41 am
Personally, rather than adding more complexity with shutters and shared/unique current inputs, if it were mandated that all meters for CAT III and up could not have a shunt, I personally would be fine with it.  I'm sure most would not agree with me.

Those meters can have current clamps so where's the problem?  :popcorn:


Harbor Freight could also give away meters that only do volts and continuity. I'm sure that's 99% of what they're used for anyway.

Exactly!  When I actually have to work in the wild, the meter I use does not have HRC fuses, or a shunt.  What's the down side? 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 23, 2017, 07:51:14 am
Exactly!  When I actually have to work in the wild, the meter I use does not have HRC fuses, or a shunt. 

The little 101?

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 07:58:30 am
I hate to bring up AN8008/ZT109 HV spacings here, but I took my AN8008 apart and it seems the rotary switch is the bottle neck?
Forget my grumblings about the fuses and poor PCB layout and fake 61010 claims.

The rotary switch PCB track spacing measures 1mm, and the wipers' spacing 0.60mm :o  so I imagine that's the limit.
I can't recall if joeqsmith has done a robustness test on this model, I think I saw the AN8002 test.

Is anybody still imagining this is a 'safe' meter?  :-//

The AN8002 did better than a Fluke 87V in joe's tests, I imagine this one will be similar.

Maybe there is only low voltage routed through the switch on the 8008.  There is not much there if someone wanted to trace it out.  Maybe the one PTC and clamp is after the switch..  :-DD.

When I ran the 8002, the switch broke down first resulting in a damaged controller. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 23, 2017, 08:06:57 am
Exactly!  When I actually have to work in the wild, the meter I use does not have HRC fuses, or a shunt. 

The little 101?

HIOKI
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 23, 2017, 11:20:17 am
I hate to bring up AN8008/ZT109 HV spacings here, but I took my AN8008 apart and it seems the rotary switch is the bottle neck?
Forget my grumblings about the fuses and poor PCB layout and fake 61010 claims.

The rotary switch PCB track spacing measures 1mm, and the wipers' spacing 0.60mm :o  so I imagine that's the limit.
I can't recall if joeqsmith has done a robustness test on this model, I think I saw the AN8002 test.

Is anybody still imagining this is a 'safe' meter?  :-//

The AN8002 did better than a Fluke 87V in joe's tests, I imagine this one will be similar.
Safety does not require the meter survives. This is a meter that is cheap enough so that if you do put it across 240V in resistance mode and some tracks evaporate, you can get another one. AN8001 type meters cost just US$12 including postage. The AN8008 was about $25.

It has been said many, many times that this is not the meter you should be using for high voltage or high energy use. I think we all understand that. Not sure why we have to keep repeating it. We get it.  :horse:

Even the best meter is only "safe" on the day it leaves the factory. If you pick up a major brand name meter that several people use, you do not know if a switch contact has broken and is floating around in the case, or if someone has shorted out a blow fuse with copper wire. It may have had a serious overvoltage incident and someone didn't report it.

If you are working with dangerous energies, it is dangerous. If anyone is risking their life on any manufacturer's CAT rating, they are definitely taking a gamble. If I have to take a gamble, Fluke is a way better gamble then ANENG, but it is better not gambling. If I did use the AN8008 with high voltage in a way where it cannot do any damage if it fails catastrophically, it is much safer then a CAT IV 600V Fluke that I am holding in my bare hands right in front of my face.

I think the AN8008 is a great little meter to use on the bench with low voltage/low power circuits. People are buying it because it can read much lower voltages and currents then most multimeters. Nothing that can be said about the safety issues is a concern for this kind of bench use. If anyone does not wish to use a meter like this for low voltages because they do not trust the CAT ratings, that is their choice.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 23, 2017, 08:44:23 pm
Safety does not require the meter survives. This is a meter that is cheap enough so that if you do put it across 240V in resistance mode and some tracks evaporate, you can get another one. AN8001 type meters cost just US$12 including postage. The AN8008 was about $25.

It has been said many, many times that this is not the meter you should be using for high voltage or high energy use. I think we all understand that. Not sure why we have to keep repeating it. We get it.  :horse:

Even the best meter is only "safe" on the day it leaves the factory. If you pick up a major brand name meter that several people use, you do not know if a switch contact has broken and is floating around in the case, or if someone has shorted out a blow fuse with copper wire. It may have had a serious overvoltage incident and someone didn't report it.

If you are working with dangerous energies, it is dangerous. If anyone is risking their life on any manufacturer's CAT rating, they are definitely taking a gamble. If I have to take a gamble, Fluke is a way better gamble then ANENG, but it is better not gambling. If I did use the AN8008 with high voltage in a way where it cannot do any damage if it fails catastrophically, it is much safer then a CAT IV 600V Fluke that I am holding in my bare hands right in front of my face.

I think the AN8008 is a great little meter to use on the bench with low voltage/low power circuits. People are buying it because it can read much lower voltages and currents then most multimeters. Nothing that can be said about the safety issues is a concern for this kind of bench use. If anyone does not wish to use a meter like this for low voltages because they do not trust the CAT ratings, that is their choice.
I personally think that this sums it all up rather nicely, rather like an MOT certificate on a 3 year old car stating that it is roadworthy, which is actually only true at the moment that the test was done. Like all things electrical and mechanical things can and do go wrong from time to time when you least expect them to and all anyone can realistically do is to reduce the impact of an accident happening by taking the required safety precautions in the first place.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 23, 2017, 11:37:13 pm
Safety is as safe as the person who is using it.
A proper (expensive) certified meter is still a ticking time bomb in the hands of someone who doesn't know what he is doing.
The point is, that grey line is stretched much further with a decent (properly certified) brand, than a cheapo meter from Ebay.
With a cheapo meter you're taking a risk and you simply don't know how and when this meter will perform in certain situations.

No deal for a hobbyist (with knowledge) IMO, but absolutely unthinkable in a professional situation.

From a practical point of view, I still don't see how even this cheapo meter can be a real potential murderer.
Worst case is that you blow the internals up. (Unless you work without any other safety precautions, which is wrong anyway)
Everybody with enough years of experience knows that these things will happen from time to time anyway.

Guess some people here have never been into a science & physics department/laboratory
Our safety fanboys and nerds would shiver.

So can we please stop the whole safety debate? I think it's clear by know that people use this thing at their own risk above certain voltages and/or currents.
That's not even beating a dead horse, but running over it a million times and than burning it.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on July 24, 2017, 12:11:43 am
From a practical point of view, I still don't see how even this cheapo meter can be a real potential murderer.
Worst case is that you blow the internals up. (Unless you work without any other safety precautions, which is wrong anyway)
If you are talking about something really dangerous like 1000V DC at 1000+ amps peak, basically you have entered a different world. If a cheap meter fails, it will probably not be able to contain the arc within the case, it may violently explode and fragment, or the internal arcing may not stop which basically means the meter will catch on fire. The ABS case will not need all that much encouragement to burn. A megawatt of electrical power is not something you ever want to see released in your hand or near your face.

Even 50V in a massive standby battery bank can be extremely scary. I have seen someone go to hospital with a first degree burn from a mistake he made working with a 4x12V 7AH battery pack. (Wearing a metal watch band while working near the batteries).

I wouldn't want to use a cheap meter in either of these cases. I would go for properly rated meter, and then still be extremely careful.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 24, 2017, 12:45:55 am
From a practical point of view, I still don't see how even this cheapo meter can be a real potential murderer.
Worst case is that you blow the internals up. (Unless you work without any other safety precautions, which is wrong anyway)
Not even in the industrial three-phase circuits this meter claims to be suitable for? Sure, the person should have been wearing personal protective equipment and should have been paying attention. But accidents always occur due to rare combinations of circumstances. If the person failed to wear proper PPE and accidentally left it set to current, and suddenly a motor stops. That is when the safety features (supposedly) built into the DMM should save you.

Guess some people here have never been into a science & physics department/laboratory
Guess again.

So can we please stop the whole safety debate?
Posting a message debating safety seems like a very good way to do that ;).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 24, 2017, 12:49:03 am
From a practical point of view, I still don't see how even this cheapo meter can be a real potential murderer.
Worst case is that you blow the internals up. (Unless you work without any other safety precautions, which is wrong anyway)
If you are talking about something really dangerous like 1000V DC at 1000+ amps peak, basically you have entered a different world. If a cheap meter fails, it will probably not be able to contain the arc within the case, it may violently explode and fragment, or the internal arcing may not stop which basically means the meter will catch on fire. The ABS case will not need all that much encouragement to burn. A megawatt of electrical power is not something you ever want to see released in your hand or near your face.

Even 50V in a massive standby battery bank can be extremely scary. I have seen someone go to hospital with a first degree burn from a mistake he made working with a 4x12V 7AH battery pack. (Wearing a metal watch band while working near the batteries).

I wouldn't want to use a cheap meter in either of these cases. I would go for properly rated meter, and then still be extremely careful.
Well, that's what I meant with practical examples.
If you release that amount of energy (which is the correct term), at ones. Yes, that's a whole different league.

But I personally wouldn't work on both with some extra safety measures.
I rarely hold my meters in my hands for example and I mostly work with an extra switchable safety fuse in these high energy cases.
I would consider these things more as professional situations.

Ones again, people should think first.
But anyway, we are going off topic once again.
Maybe a separate topic (and sticky!) on this would be a nice idea.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 24, 2017, 12:57:11 am
Guess again.

So can we please stop the whole safety debate?
Posting a message debating safety seems like a very good way to do that ;).
I know, but it's just to interesting to keep our mouths shut I guess  ;D ;D

I have a physics background, and have been to many laboratories and test facilities.
Mostly the safety regulations are pretty mild. That all has to do with the fact that the people who work there all educated enough to oversee the dangers.
To give you another example. If you do research on radioactive material you're actually allowed to have a much higher dosage of radiation.
The reason why is because these people are trained and know how to handle is certain situations.
It always has been a big mystery to me why this doesn't apply in the field of electronics
(I can tell you from personal experience that radioactive material can be MUCH more dangerous!!)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 24, 2017, 01:53:50 am
Guess some people here have never been into a science & physics department/laboratory
I for one have been in many such labs and also many ASTA certificated ones as well and have seen first hand the huge destructive power of electricity with the damage done to bullet proof glass and walls that have been subjected to the fragments of electrical equipment that has blown apart as a result of them being tested to destruction in safety checks.

Equipment used on high energy sources should be suitably rated and in the real world shouldn't this equipment be in the hands of suitable skilled and qualified people and only such persons should be allowed anywhere near such energy sources? Also it should be true that a multimeter is not the correct tool for the job anyway when working on these types of installation live, the the test equipment should be designed and to restricted to being able to measure just voltage only and multimeters restricted to working on dead and isolated circuits only?

It is perfectly possible to purchase all kinds of equipment designed to be used by a surgeon such as a scalpel for instance, but having one does not make you a surgeon, the individual using these tools has to accept some responsibility for their actions and understand their own abilities. I have a driving license, on that license I can drive a coach or a bus even but not with fare paying passengers on it, and I have driven these on many occasions BUT I would never dream of crossing into an area that I was not suitably qualified for. The same should be true in the electrical and electronics world, people have to know and acknowledge their own limitations, we cannot design fool proof equipment in every instance. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 24, 2017, 02:29:15 am
I guess we can now answer this topic's initial question: Yes, a $25 multimeter is clearly good for something -- at the very least, it makes a great conversation piece.  ::)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 24, 2017, 02:34:03 am
I for one have been in many such labs and also many ASTA certificated ones as well and have seen first hand the huge destructive power of electricity with the damage done to bullet proof glass and walls that have been subjected to the fragments of electrical equipment that has blown apart as a result of them being tested to destruction in safety checks.

True, but most of these cheapo meters will only be used in a CAT II 300V environment, even by the reckless idiots.

(with maybe an occasional foray into CAT III 300V)

Plus: One of these is waaaay safer than the DT830B they'd be using if the only alternative was a $100 CAT rated meter.

It is perfectly possible to purchase all kinds of equipment designed to be used by a surgeon such as a scalpel for instance, but having one does not make you a surgeon...
:horse:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 24, 2017, 02:40:11 am
True, but most of these cheapo meters will only be used in a CAT II 300V environment even by the reckless idiots.

(with maybe an occasional foray into CAT III 300V)
Agreed. Does that make lying about it acceptable, though? Would it be acceptable to mark the same meter as bomb detector (http://www.bbc.com/news/uk-22380368), because most users are unlikely to run into bombs?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 24, 2017, 02:44:04 am
True, but most of these cheapo meters will only be used in a CAT II 300V environment even by the reckless idiots.

(with maybe an occasional foray into CAT III 300V)
Agreed. Does that make lying about it acceptable, though?

No, but changing what ANENG prints on the front of its meters is out of our hands.

The public don't know what the markings mean anyway, removing them would make very little difference.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 24, 2017, 03:22:03 am
Well, not sending ANENG dozens of orders would be a start ;). As would be not recommending any meter that so blatantly lies about its safety.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 24, 2017, 04:04:07 am
Well, not sending ANENG dozens of orders would be a start ;). As would be not recommending any meter that so blatantly lies about its safety.

How can I not recommend a $15 meter that does all this?

Making people aware is always the best solution, not trying to ban/censor.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MacMeter on July 24, 2017, 04:07:20 am
Well, not sending ANENG dozens of orders would be a start ;). As would be not recommending any meter that so blatantly lies about its safety.

I bought one as I'd like to believe I kinda know what I'm doing. But in an effort to continue to beat this dead horse some more, I do take issue with ALL the FAKE labels, on many Chinese products, this includes UL listings etc. Besides the fact it's lying and deceptive, and can be very unsafe for many not knowing about this ongoing practice. And this of course extends well beyond DDM's. So far it seems there is little we can do to dissuade the Chinese from these deceptive practices, and the old "vote with your wallet", has had little effect so far, as many simply buy the cheapest products they can find, with little regard to how honesty the product may be marketed. Making others aware of these false labels is a good thing for those that may read online reviews and forum posts, regardless how many times the horse is beaten.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 24, 2017, 04:34:33 am
The public don't know what the markings mean anyway, removing them would make very little difference.

Based on the number of comments I receive, a fairly high percentage of people buying meters don't know what they mean.  Strange with having the internet at your fingertips.   But not making the standards available to the public does not help. 

If it were important, there would be government funded watchdog groups that spot checked the companies who self certify.   Meters do not pose the same threat as food for example so there is no FDA equivalent.  Imagine if this group were able to impose fines if they failed to meet their claimed ratings or prevent import/exporting of the product.    Even if there were such a branch like the FDA, I can see like DOT standards for helmets, were we could have a private watchdog like Snell if the problem were really big enough. 

Just blabbing....

Imagine extending this to the world of handheld meters, Snell vs DOT:

http://www.smf.org/docs/articles/dot (http://www.smf.org/docs/articles/dot)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MacMeter on July 24, 2017, 04:48:55 am
The public don't know what the markings mean anyway, removing them would make very little difference.

Based on the number of comments I receive, a fairly high percentage of people buying meters don't know what they mean.  Strange with having the internet at your fingertips.   But not making the standards available to the public does not help. 

If it were important, there would be government funded watchdog groups that spot checked the companies who self certify.   Meters do not pose the same threat as food for example so there is no FDA equivalent.  Imagine if this group were able to impose fines if they failed to meet their claimed ratings or prevent import/exporting of the product.    Even if there were such a branch like the FDA, I can see like DOT standards for helmets, were we could have a private watchdog like Snell if the problem were really big enough. 

Just blabbing....

Imagine extending this to the world of handheld meters, Snell vs DOT:

http://www.smf.org/docs/articles/dot (http://www.smf.org/docs/articles/dot)

Agreed, but it seems the Chinese, and perhaps other countries don't seem to care much about adhering to any standards, international or not. They even clone their own clones of products.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 24, 2017, 05:09:45 am
Making people aware is always the best solution, not trying to ban/censor.
Making people aware is what half this thread is about :P. I would like to see equipment with fake safety markings banned, but I do not think anyone was talking about censoring the discussion.

Based on the number of comments I receive, a fairly high percentage of people buying meters don't know what they mean.  Strange with having the internet at your fingertips.   But not making the standards available to the public does not help. 
Having scanned through some of those standards, I am not convinced that publishing them freely would do anything to educate the public. Not that I am arguing against freely available standards, but it would do about as much for education as reading a copy of Heaviside's paper on Maxwell's equations for understanding of electricity. Basic information about test equipment safety is available for free in white papers from the likes of National Instruments (http://www.ni.com/white-paper/5019/en/) and Fluke (http://content.fluke.com/promotions/promo-dmm/0518-dmm-campaign/dmm/fluke_dmm-chfr/files/safetyguidelines.pdf).

If it were important, there would be government funded watchdog groups that spot checked the companies who self certify.
Even in the EU, where there are such groups (collected in the interestingly named RAPEX (https://ec.europa.eu/consumers/consumers_safety/safety_products/rapex/alerts/repository/content/pages/rapex/index_en.htm)), they can only cover a tiny fraction of all products, and seem to focus mostly on consumer products. If the consumer imports their own stuff through eBay/AliExpress, how is any national organization going to test it? Putting a Hi-Pot tester at the customs office? Order random stuff from AliExpress and test it?

I imagine eventually a bunch of people will die due to defective products, there will be outcry, and there will be some knee-jerk response from politicians like requiring a license to import anything electronic.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 24, 2017, 05:17:10 am
Based on the number of comments I receive, a fairly high percentage of people buying meters don't know what they mean.  Strange with having the internet at your fingertips.   But not making the standards available to the public does not help. 

Not strange.

Even Fluke's basic "ABCs of multimeter safety" says things like:

Code: [Select]
CAT I
• Protected electronic equipment
• Equipment connected to (source) circuits in which measures
are taken to limit transient overvoltages to an appropriately
low level
• Any high-voltage, low-energy source derived from a high-
winding resistance transformer, such as the high-voltage
section of a copier

Is Joe Public expected to understand that?

What they need is clear advice like "Get CAT III 600V for mains work"

I don't see any reason to go for less when you can get that for $42.

(and I'm sure China could make that for $15 if they had an incentive - all they need to do is remove the current ranges and spend a few cents on making the meter die without drama if overloaded).

Even better, a big colored symbol which indicates "Safe for mains AC" and leave the CAT ratings for the engineers.

Yes, it divides the multimeter world into "mains rated" and "not" but I don't see that as a problem.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on July 24, 2017, 05:20:04 am
It seems that we have found a good solution to the unfortunate situation that two threads were discussing the same new AN8008 meter:
Please keep it up! This enables me to unsubscribe from this thread, and just monitor the other one .
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 24, 2017, 06:01:39 am
I agree, the standards are dry and there is a lot of room for interpreting them.  It seems even the designers do not agree.   But keeping them out of the public where they could be discussed in detail seems to counter the whole point of having them.   Personally I would expect the entire reports to be made public.   The public ends up paying for the testing in the end anyway.   

I view multimeters a little different than most products, thinking people that would buy this type of product would have some technical knowledge.  But right there you can see that my thinking is flawed!!!  :-DD   

I wonder what drove UNI-T to offer the GS version of the UT61E.   To Fungus's comment, if the body is not going to ensure the mark has any credibility, there was no reason for mandating it in the first place.   

Quote
.... how is any national organization going to test it? Putting a Hi-Pot tester at the customs office? Order random stuff from AliExpress and test it?

That's a very good question.  I think Snell started out doing just that.  Buying a small number of helmets, testing them then making the results public.  Eventually you started to see articles in popular magazines that helped educate the public.   Over time, people like me started using that public list to determine what to buy.   I would not use a helmet that was not Snell approved.  It's a fairly high risk hobby in the first place and proper gear is important.     

I can tell you from my own little benchmarking, unlike with Snell, it's driven out of general curiosity rather than a tragic death of a friend. Had it been the later, I may have been following the actual surge tests rather than what is more important to me, robustness or the meters ability to survive some minimal transients.    Believe me, I have zero thought of ever trying to turn it into a money making business or charging for the information I collect.  But, you may be amazed at the backlash I receive from running such tests!   :-DD 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 24, 2017, 06:03:07 am
Based on the number of comments I receive, a fairly high percentage of people buying meters don't know what they mean.  Strange with having the internet at your fingertips.   But not making the standards available to the public does not help. 

Not strange.

Even Fluke's basic "ABCs of multimeter safety" says things like:

Code: [Select]
CAT I
• Protected electronic equipment
• Equipment connected to (source) circuits in which measures
are taken to limit transient overvoltages to an appropriately
low level
• Any high-voltage, low-energy source derived from a high-
winding resistance transformer, such as the high-voltage
section of a copier

Is Joe Public expected to understand that?

What they need is clear advice like "Get CAT III 600V for mains work"

I don't see any reason to go for less when you can get that for $42.

(and I'm sure China could make that for $15 if they had an incentive - all they need to do is remove the current ranges and spend a few cents on making the meter die without drama if overloaded).

Even better, a big colored symbol which indicates "Safe for mains AC" and leave the CAT ratings for the engineers.

Yes, it divides the multimeter world into "mains rated" and "not" but I don't see that as a problem.

I agree about the need to have some VERY CLEAR ADVICE!   You could publish a new book, "Making measurements safely" and it would sell, maybe...  Well, I would read it anyway.     

Your target audience should be the 10 year old who goes on a take your kid to work day, and gets to be on the factory floor and make some measurements, without supervision....   If you could put it in terms that the video game playing 10 year old understands, I believe you have a hit.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 24, 2017, 06:15:27 am
Your target audience should be the 10 year old who goes on a take your kid to work day, and gets to be on the factory floor and make some measurements, without supervision....   If you could put it in terms that the video game playing 10 year old understands, I believe you have a hit.

A video game with multimeters, you say? Okay, you didn't say it, but... if such a thing would have a market and be sponsored by someone with a budget, e.g. Fluke, I'm sure someone would take the challenge. A hero electrician saving the day. The more safety procedures are observed, more points are received.

But on the serious side, I'm sure no one wants people learning about multimeters and safety from games.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: alm on July 24, 2017, 06:16:30 am
What they need is clear advice like "Get CAT III 600V for mains work"
And then they go out and buy an AN-8008 :P.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 24, 2017, 06:18:25 am
Surely, at least for those here in the United Kingdom there is no need to use a multimeter on mains supplies which is where most people will come across high energy sources as this link clearly demonstrates.

http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html (http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html)

Using these devices in the link meets all the HSE requirements and also the Wiring Regulations as well as removed the chance of operator error, even if the circuit is live as there is no range switch, or current ranges etc that could be selected. Using these devices will ensure 100% safety for the operators of such equipment, no??? 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 24, 2017, 06:35:28 am
Surely, at least for those here in the United Kingdom there is no need to use a multimeter on mains supplies which is where most people will come across high energy sources as this link clearly demonstrates.

http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html (http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html)

Using these devices in the link meets all the HSE requirements and also the Wiring Regulations as well as removed the chance of operator error, even if the circuit is live as there is no range switch, or current ranges etc that could be selected. Using these devices will ensure 100% safety for the operators of such equipment, no???

You can use such a voltage indicator to check that a circuit has been de-energized, but after that you may need to check continuity or resistance on circuits. That device doesn't say it can test continuity. So what happens if you are testing continuity or resistance with a multimeter and you accidentally test a live circuit?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 24, 2017, 09:06:48 am
Surely, at least for those here in the United Kingdom there is no need to use a multimeter on mains supplies which is where most people will come across high energy sources as this link clearly demonstrates.

http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html (http://martindale-electric.co.uk/martindale-vi-15000-voltage-indicator-p-1870.html)

Using these devices in the link meets all the HSE requirements and also the Wiring Regulations as well as removed the chance of operator error, even if the circuit is live as there is no range switch, or current ranges etc that could be selected. Using these devices will ensure 100% safety for the operators of such equipment, no???

You can use such a voltage indicator to check that a circuit has been de-energized, but after that you may need to check continuity or resistance on circuits. That device doesn't say it can test continuity. So what happens if you are testing continuity or resistance with a multimeter and you accidentally test a live circuit?
Thats the whole point, you do not get out the multimeter until you have confirmed that the circuit is dead and isolated safely by padlocking it off. Risk from using multimeter on the wrong range should then be zero. This is indeed what electrical engineers who work on large circuits such as factories etc are trained to do. The problem arises when unqualified and unsupervised people start to dabble in areas that they should not be anywhere near. These, multi padlock devices are nothing new, they have been around for decades, I remember them when I did my apprenticeship and I'm retired now. The safety issues and the need for these CAT ratings have in my opinion been largely driven by the continual decline in trade disciplines by employers driving the cost down by employing in less well qualified staff and then make them into multi-discipline trades people so 1 person can do the work of 2 or more people, thereby increasing their profits. But that is another topic all together and here in the UK we have seen some staggering examples of how cost cutting can have devastating effects on the lives of others. Thats another can of worms that is currently best left untouched, this an engineering forum, not political.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 24, 2017, 09:15:43 am
Well, at least for non-professionals on this forum, do we have a safety guide written somewhere (either as a post or a video)?
Perhaps some basics on safety when using a meter, aimed at novices rather than professionals.

Ah, it's probably all around the forum. :)



Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 24, 2017, 12:57:15 pm
Thats the whole point, you do not get out the multimeter until you have confirmed that the circuit is dead and isolated safely by padlocking it off. Risk from using multimeter on the wrong range should then be zero. This is indeed what electrical engineers who work on large circuits such as factories etc are trained to do.

Working in an industrial setting is one thing. But I wasn't thinking of that. I was thinking of working in non-industrial settings like residential buildings and office spaces, HVAC systems and such like. Does your home have multi-padlock safety interlocks? Can you be sure that all the wires in a junction box are on the same breaker? They should be, but there are certain cases in old buildings (and my house) where they aren't.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 24, 2017, 01:27:18 pm
Personally, I liked the 8002 for what it was.   It had lots of features including temperature, low cost and small.  I think I was able to read 200MHz with it.  Compare that with the Gossen and 121GW at 1MHz.  If I wanted to mod the meter for low voltage use (besides removing the CAT marking) I wonder if there is enough room in there to add some basic protection.   

Looks like the 10A fuse was open. The PTC seems fine. 

If anything, gives you some idea of what went on inside the meter.  Keep in mind this thing actually out survived the Dave's 121GW.  It would have done very well in that very first set of tests I ran with the sub $50 meters.       
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 24, 2017, 06:14:04 pm
Thats the whole point, you do not get out the multimeter until you have confirmed that the circuit is dead and isolated safely by padlocking it off. Risk from using multimeter on the wrong range should then be zero. This is indeed what electrical engineers who work on large circuits such as factories etc are trained to do.

Working in an industrial setting is one thing. But I wasn't thinking of that. I was thinking of working in non-industrial settings like residential buildings and office spaces, HVAC systems and such like. Does your home have multi-padlock safety interlocks? Can you be sure that all the wires in a junction box are on the same breaker? They should be, but there are certain cases in old buildings (and my house) where they aren't.

I think that to a large extent the CAT ratings have been used as a marketing tool by some company's even driven by them.

There are lock out devices for domestic switch boards and offices HVAC etc and should be used especially where there are other people working on the system or where there are people who might turn the power back on when they find the coffee machine or whatever is not working. Lock out devices should be used by more than electricians, I know of a case where a farm worker was cleaning an elevator, he had done all the proper things like turn off the main power switch. Unfortunately for him someone else came into the barn saw the lights were out and went and turned the power back on, this started the elevator and he was pulled in and drawn halfway up before the idiot that turned the power on heard his screams realized what was going on and turned the power off again, when the fire brigade arrived to extricate the man they had to turn the power on and wind the man the rest of the way up the elevator in order to get him out by that time his hand was in a pretty poor state. So any one who is going to do any thing which involves shutting off power needs to be able to make sure the power is not coming back on until they are ready and it is safe.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 24, 2017, 06:48:16 pm
Thats the whole point, you do not get out the multimeter until you have confirmed that the circuit is dead and isolated safely by padlocking it off. Risk from using multimeter on the wrong range should then be zero. This is indeed what electrical engineers who work on large circuits such as factories etc are trained to do.

Working in an industrial setting is one thing. But I wasn't thinking of that. I was thinking of working in non-industrial settings like residential buildings and office spaces, HVAC systems and such like. Does your home have multi-padlock safety interlocks? Can you be sure that all the wires in a junction box are on the same breaker? They should be, but there are certain cases in old buildings (and my house) where they aren't.

I think that to a large extent the CAT ratings have been used as a marketing tool by some company's even driven by them.
I don't even think that, I am sure about it.

On top of that I have seen many people, who would never ever work on these high energy projects, but they still would rather buy a high CAT rating multimeter.
Just because it gives a sense of trust I guess. But technically speaking it's absolutely not important.
Most people don't even use their meter for mains power (115/230V)

Like I said before, I would never work on these type of projects with some extra safety features besides my multimeter.
One very good safety feature is simply sending people away or preventing them for even coming close to the things I am working on at the moment.
In most stories you read, the worst accidents happen when other people did something you didn't want in the first place.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 24, 2017, 07:37:27 pm
On top of that I have seen many people, who would never ever work on these high energy projects, but they still would rather buy a high CAT rating multimeter.

We're now up to page 15 of that debate in this thread and there are many others.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: labeanchik on July 24, 2017, 07:40:05 pm
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.
If the other specs are as credible, I'll pass on it...

EDIT: I see that they have photos of two slightly different meters in that product description. They seem to have added space for the extra "1" in a revised version.

(http://ae01.alicdn.com/kf/HTB18jZYSXXXXXXLaFXXxh4dFXXX6.jpeg)

Here is  this?

https://www.banggood.com/ru/ZEAST-282-20000counts-Multimeter-Digital-Professional-Voltmeter-Current-Tester-Auto-True-RMS-p-1175450.html?rmmds=detail-bottom-viewalsoview (https://www.banggood.com/ru/ZEAST-282-20000counts-Multimeter-Digital-Professional-Voltmeter-Current-Tester-Auto-True-RMS-p-1175450.html?rmmds=detail-bottom-viewalsoview)

https://www.banggood.com/ru/HY-19E-20000-Counts-NCV-Multimeter-AC-DC-Voltage-Current-Resistances-Capacitors-Diodes-Temp-Tester-p-1153062.html?rmmds=detail-bottom-viewalsoview (https://www.banggood.com/ru/HY-19E-20000-Counts-NCV-Multimeter-AC-DC-Voltage-Current-Resistances-Capacitors-Diodes-Temp-Tester-p-1153062.html?rmmds=detail-bottom-viewalsoview)

https://www.banggood.com/ru/ZEAST-HY-19A-6000Counts-Digital-Multimeter-LCD-Backlight-Auto-AC-DC-Voltmeter-Ammeter-Ohm-Resistance-p-1175452.html?rmmds=newArrivals (https://www.banggood.com/ru/ZEAST-HY-19A-6000Counts-Digital-Multimeter-LCD-Backlight-Auto-AC-DC-Voltmeter-Ammeter-Ohm-Resistance-p-1175452.html?rmmds=newArrivals)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: madires on July 24, 2017, 08:17:28 pm
On top of that I have seen many people, who would never ever work on these high energy projects, but they still would rather buy a high CAT rating multimeter.
Just because it gives a sense of trust I guess. But technically speaking it's absolutely not important.
Most people don't even use their meter for mains power (115/230V)

IMHO, the problem is that the common EE or hobbyist would use his DMM on mains because that's the tool he got. So he's looking for proper CAT ratings, despite a DMM for electronics isn't the right tool for mains. The proper tools for mains are a Duspol or similar voltage indicator with a switchable low impedance mode for usual tasks, a rugged DMM for sparkies without current measurement, a clamp meter for current measurements (the 10 or 20A range of an electronics DMM is laughable) and isolation/wiring testers. The Duspol needs two hands for operation, a DMM three. Clips, hangers and magnets are nonsense if you're on a ladder working on a junction box above you. If you're working on high voltage or high current stuff you will need another set of tools again.

TL;DR: Using an electronics DMM on mains is as bad as a neon screwdriver.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on July 24, 2017, 08:26:44 pm
Revolutionary! The first 4 1/2 digit multimeter with only 4 digits in the display.
If the other specs are as credible, I'll pass on it...

EDIT: I see that they have photos of two slightly different meters in that product description. They seem to have added space for the extra "1" in a revised version.

(http://ae01.alicdn.com/kf/HTB18jZYSXXXXXXLaFXXxh4dFXXX6.jpeg)

Here is  this?

https://www.banggood.com/ru/ZEAST-282-20000counts-Multimeter-Digital-Professional-Voltmeter-Current-Tester-Auto-True-RMS-p-1175450.html?rmmds=detail-bottom-viewalsoview (https://www.banggood.com/ru/ZEAST-282-20000counts-Multimeter-Digital-Professional-Voltmeter-Current-Tester-Auto-True-RMS-p-1175450.html?rmmds=detail-bottom-viewalsoview)

https://www.banggood.com/ru/HY-19E-20000-Counts-NCV-Multimeter-AC-DC-Voltage-Current-Resistances-Capacitors-Diodes-Temp-Tester-p-1153062.html?rmmds=detail-bottom-viewalsoview (https://www.banggood.com/ru/HY-19E-20000-Counts-NCV-Multimeter-AC-DC-Voltage-Current-Resistances-Capacitors-Diodes-Temp-Tester-p-1153062.html?rmmds=detail-bottom-viewalsoview)

https://www.banggood.com/ru/ZEAST-HY-19A-6000Counts-Digital-Multimeter-LCD-Backlight-Auto-AC-DC-Voltmeter-Ammeter-Ohm-Resistance-p-1175452.html?rmmds=newArrivals (https://www.banggood.com/ru/ZEAST-HY-19A-6000Counts-Digital-Multimeter-LCD-Backlight-Auto-AC-DC-Voltmeter-Ammeter-Ohm-Resistance-p-1175452.html?rmmds=newArrivals)
The last one looks like a DTM0660 chip multimeter. It would be interesting to check the internals and UART modifications.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 24, 2017, 09:08:36 pm
We're now up to page 15 of that debate in this thread and there are many others.
Yep, thats because safety is an issue to most people and has to be taken seriously but with a balanced view on how and where the meter is going to used and your own skill set has to be taken into the equation as well. As has been already been mentioned, some people would rather buy a meter with decent compliance to the Cats and regulations even though they are not using it in the dangerous environments, just as a added feeling of security etc. or feel good factor.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: cjs on July 24, 2017, 11:42:19 pm
Is Joe Public expected to understand that?
What they need is clear advice like "Get CAT III 600V for mains work"

I think that's terrible advice, even if meters all had valid and tested category ratings. It's way easy to hurt yourself with any meter, no matter how good, if you don't know what you're doing.

Instead tell people "don't touch mains until you've had some minimal proper training," and then you can explain whatever you need about categories along with other essentials like PPE, proper work habits, and so on. In that context, phony meter category markings seem to me pretty near a non-issue because learning about how to deal with that is such a small part of the overall education.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 12:20:58 am
Instead tell people "don't touch mains until you've had some minimal proper training," and then you can explain whatever you need about categories along with other essentials like PPE, proper work habits, and so on.

Here in the real world the rednecks have been busy stockpiling their DT830Bs for decades.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Muttley Snickers on July 25, 2017, 12:22:52 am
I know this is another $25 meter ($24.99 actually) but this coming Saturday, ALDI is offering this one.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333267;image)

Wonder what it would be like inside....?

I was over at Aldi today and whilst there I picked one of these meters up  :-+ and then promptly put it back down again  :-- , I even have the receipt to prove that I didn't buy one, I did however purchase a bag of muesli and two boxes of apple and blueberry tarts.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 25, 2017, 12:33:17 am
Instead tell people "don't touch mains until you've had some minimal proper training,"
Or use their brains properly and think.

Btw, in a lot of countries you don't need any qualifications to work on mains (after the main fuse)
Their is also nothing super dangerous about it.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 12:34:53 am
I was over at Aldi today and whilst there I picked one of these meters up  :-+ and then promptly put it back down again

Me too. The whole feel of it just says: "Nothing about me will be fun/interesting and I'm so mediocre you won't ever use me".

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 12:37:14 am
Instead tell people "don't touch mains until you've had some minimal proper training,"
Or use their brains properly and think.

Good luck with that plan.  :-DD :-DD :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 25, 2017, 12:40:26 am
Instead tell people "don't touch mains until you've had some minimal proper training,"
Or use their brains properly and think.

Good luck with that plan.  :-DD :-DD :-DD
I know......

But you can make a billion rules, regulations, train courses.
If people simply don't use their brains and are not REALLY aware of why things can go wrong, it's kind of pointless anyway.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on July 25, 2017, 01:08:27 am
People need to have some knowledge about a subject in order to be able to use their brains.  The old days of needing to know some of the details in order to use a product are way behind us.

You no longer need to have a basic mechanical understanding of a motor vehicle to be able to use one on a daily basis.  Many years ago it was helpful - and in the early day, essential.

The same goes for electrical products - very much enabled by the manufacturers who want to make ownership and use of their products simple, to appeal to a wider market.


So - somewhere along the line, some knowledge needs to be imparted .... but by whom?

To criticise people for not using their brains is grossly unfair when they do not have the information necessary to do so.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fsck on July 25, 2017, 01:35:15 am
Instead tell people "don't touch mains until you've had some minimal proper training,"
Or use their brains properly and think.

Btw, in a lot of countries you don't need any qualifications to work on mains (after the main fuse)
Their is also nothing super dangerous about it.
you seem to underestimate the general level of competence.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on July 25, 2017, 01:46:13 am
Instead tell people "don't touch mains until you've had some minimal proper training,"
Or use their brains properly and think.

Btw, in a lot of countries you don't need any qualifications to work on mains (after the main fuse)
Their is also nothing super dangerous about it.
you seem to underestimate the general level of competence.
No, I am aware of the "general level of competence".
Maybe it's a cultural thing, but to me these things are just common sense. General knowledge if you will.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 25, 2017, 01:54:02 am
To criticise people for not using their brains is grossly unfair when they do not have the information necessary to do so.
Yes, it is unfair if they don't have the info.

But - when the only impression beginners get is that the multimeter itself is the dangerous part we are heading in the wrong direction. Yes, a proper CAT-rated multimeter will probably not explode if they try to measure the short circuit current in the wall sockt.  But, this CAT-rating will not help them if they poke their fingers into the same socket either deliberately or by accident.

If we want to inform beginners, we should instead help them to ask themselves "why would I like to poke my multimeter into the wall socket when I know nothing about electricity?"

Almost every person above 8 - 10 year old and living in a country with access to mains will know that the wall socket can be dangerous. Therefore we should help them to understand why it is dangerous. Telling them to get a proper meter does not remove the real danger.

I have spent a lot of time with beginners. Only a few of them have any idea about CAT, and those who have believes it is something the pros need to know about because of some workplace regulations. Since they are not a pro, they don't need to worry, they think.

And most likely this will not do any serious harm to them. If exploding multimeters in the hands of beginners had been a real problem, Harbour Freight would have been sued back to the stone age by american lawyers. Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 02:34:51 am
If we want to inform beginners, we should instead help them to ask themselves "why would I like to poke my multimeter into the wall socket when I know nothing about electricity?"

Easy: "To show how clever we are with the amazing multimeter!"

My answer: Hand them a key with a plastic cover and ask them to stick it in the socket. Watch the cognitive dissonance unfold.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=334793;image)

"Do you feel clever now?"

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 25, 2017, 03:08:31 am
I know this is another $25 meter ($24.99 actually) but this coming Saturday, ALDI is offering this one.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=333267;image)

Wonder what it would be like inside....?

I was over at Aldi today and whilst there I picked one of these meters up  :-+ and then promptly put it back down again  :-- , I even have the receipt to prove that I didn't buy one, I did however purchase a bag of muesli and two boxes of apple and blueberry tarts.
The meter if used properly in the right pair of hands is probably going to be OK, the most likely thing wrong with it is that little adaptor for the thermocouple that is likely to get lost before you need it.  :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 03:19:42 am
The meter if used properly in the right pair of hands is probably going to be OK, the most likely thing wrong with it is that little adaptor for the thermocouple that is likely to get lost before you need it.  :-DD

It will be the Kia Rio of the multimeter world.

There's nothing actually wrong with it, but you wouldn't want to own one.

http://www.kia.com/us/en/build/rio/2017/trims?trim=2&model=603 (http://www.kia.com/us/en/build/rio/2017/trims?trim=2&model=603)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 25, 2017, 04:14:03 am
The meter if used properly in the right pair of hands is probably going to be OK, the most likely thing wrong with it is that little adaptor for the thermocouple that is likely to get lost before you need it.  :-DD

It will be the Kia Rio of the multimeter world.

There's nothing actually wrong with it, but you wouldn't want to own one.

http://www.kia.com/us/en/build/rio/2017/trims?trim=2&model=603 (http://www.kia.com/us/en/build/rio/2017/trims?trim=2&model=603)
Well now that depends on if it was my money buying the Kia or not, the quality must be there as they offer it with a 10 year or 100,000 warranty versus the meters 1 year?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 04:22:34 am
the quality must be there as they offer it with a 10 year or 100,000 warranty

Maybe it's just not exciting enough to wear itself out.

The sales bullet points are:
* It has an engine (and it's economical!)
* It has brakes (on all four wheels!)
* It has a radio

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=334837;image)

That's it. That's literally the most interesting things even the sales team could find to say about this car.

Does that make you want to rush out and buy one?


versus the meters 1 year?

I'm sure that Aldi meter would outlast most of us if we bought it.

(and for the same reasons)

Title: These multimeters a result of communism
Post by: floobydust on July 25, 2017, 04:48:18 am
Reading the chinese forums, these multimeters appear to be a result of communism.

The government mandated the need for low-cost precision multimeters, in order to improve the nation.
The result is planning and fab of single-chip DMM IC's, which make these low dollar meters possible.
There is great national pride in this accomplishment.
In the USA, Maxim MAX134 3-3/4 digit 4,000 count DMM IC  (https://www.maximintegrated.com/en/products/analog/data-converters/analog-to-digital-converters/MAX134.html)circa 1995, last decent DMM IC I could buy.

In china they are envious of Fluke multimeters, considered the ultimate, like owning Gucci or Mercedes but far too expensive for the majority.

Of course safety is unimportant, hence the fake claims of meeting 61010.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: drussell on July 25, 2017, 05:24:23 am
Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.

North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: G7PSK on July 25, 2017, 05:50:07 am
Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.

North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....
Well if we are going that route, ours are 415 with an earthed center tap. :horse:
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 06:26:24 am
Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.

North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....
Well if we are going that route, ours are 415 with an earthed center tap. :horse:

Ours are 400kV at the substation. I'm not sure where they put the taps.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on July 25, 2017, 06:30:36 am
North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....
Well if we are going that route, ours are 415 with an earthed center tap. :horse:

Except that I have 240 V actually present in my house and delivered by various wall sockets...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 25, 2017, 06:39:11 am
Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.

North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....

Yes, I know. The difference is that the normal wall socket in Europe is 230V and in the North America it is 120V. I know you have 240V for more power hungry equipment too.

Funny thing about the European TN-system is that you can have 400V if you measure between the live wires of two sockets fed from different phases. The three phases are distributed evenly around the house so the load on the three phase system is balanced. You can have two adjacent sockets (at least in some countries) fed from different phases.  The damage potential of 400V is a lot more than from 230V. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on July 25, 2017, 07:57:23 am
the quality must be there as they offer it with a 10 year or 100,000 warranty

Maybe it's just not exciting enough to wear itself out.

The sales bullet points are:
* It has an engine (and it's economical!)
* It has brakes (on all four wheels!)
* It has a radio

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=334837;image)

That's it. That's literally the most interesting things even the sales team could find to say about this car.

Does that make you want to rush out and buy one?


versus the meters 1 year?

I'm sure that Aldi meter would outlast most of us if we bought it.

(and for the same reasons)
Just maybe the sales blurb is uninspiring because thats they way that they think cars should be sold, based on ethical things rather than making claims about its performance such as 0-60mph time, its go design language etc etc. and instead pushing its green credentials etc, which I think Korea is a country that prides itself on being green. Who knows the reason behind it, one thing for sure is that they don't make false claims about their cars. And no, I wouldn't buy one of those cars although I have looked at their Optima range of cars a while ago and decided to stick with my Skoda Superb because it does everything that I want it to and does it well. Being an engineer I can look past all the marketing hype and appreciate the engineering honesty and standard of construction etc.

Much the same as when it comes down to choosing a multimeter, I look at it, its ranges, specification, and evaluate it and the useage that I'm going to be subjecting it to and then make, hopefully a well informed decision rather than buying something that is over engineered and thus over priced for the function its going to be used for.  :-DMM
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on July 25, 2017, 08:01:02 am
Just maybe the sales blurb is uninspiring because thats they way that they think cars should be sold, based on ethical things rather than making claims about its performance such as 0-60mph time, its go design language etc etc. and instead pushing its green credentials etc
Does that vision include the radio?

Much the same as when it comes down to choosing a multimeter, I look at it, its ranges, specification, and evaluate it and the useage that I'm going to be subjecting it to and then make, hopefully a well informed decision rather than buying something that is over engineered and thus over priced for the function its going to be used for.  :-DMM
Which meter did you choose?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 25, 2017, 09:09:17 am
Even in Europe with our 230/240V mains I have still not heard about exploding meters in the hands of beginners being a big thing.

North American mains are 240 volt also, they're just center-tapped with the tap grounded for the typical residential installation.  It is still 240 volt....
Well if we are going that route, ours are 415 with an earthed center tap. :horse:

Ours are 400kV at the substation. I'm not sure where they put the taps.


I was at a place that was using 765KV, I think at a couple of GWs.   
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on July 25, 2017, 10:56:05 am
This 61010 annex I covers world-wide mains systems on the distribution secondary. I find it useful as North America, Europe, Japan can be quite different.

I worked for an electric utility. Huge difference between transmission, distribution, residential voltages and equipment. The big subs were 240kV and 144/72kV for smaller ones. A high stress job, no mistakes allowed.

These low dollar multimeters, if they are safe or not on residential mains, it's unfortunate the discussion seems to spin around.



Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 26, 2017, 04:46:26 am
The proper tools for mains are a Duspol or similar voltage indicator with a switchable low impedance mode for usual tasks, a rugged DMM for sparkies without current measurement, a clamp meter for current measurements (the 10 or 20A range of an electronics DMM is laughable) and isolation/wiring testers. The Duspol needs two hands for operation, a DMM three.

Since you've mentioned occasionly a Duspol, here is a picture of mine:

 :D

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 26, 2017, 01:52:37 pm
Looks like we are moving out of the 61010 standards now.   I've thought about trying to get my hands on a HV probe for the fun of it but price was more than I was willing to give up.   It would be interesting to see how they are made.     
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BU508A on July 26, 2017, 04:35:23 pm
Looks like we are moving out of the 61010 standards now.   I've thought about trying to get my hands on a HV probe for the fun of it but price was more than I was willing to give up.   It would be interesting to see how they are made.   

Do you mean these Benning Duspol things?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 26, 2017, 09:26:21 pm
Looks like we are moving out of the 61010 standards now.   I've thought about trying to get my hands on a HV probe for the fun of it but price was more than I was willing to give up.   It would be interesting to see how they are made.   

Do you mean these Benning Duspol things?
Since the 61243 standard is on the table, I was thinking about those voltage detectors on the poles that they use at the substations.  I don't know anything really about them or the 61243 standards.  It's a whole new world. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tronde on July 27, 2017, 01:49:36 am
A place to begin.
Russian version of  61243-3-2014. Use google translate.

http://docs.cntd.ru/document/1200115411 (http://docs.cntd.ru/document/1200115411)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: joeqsmith on July 27, 2017, 02:10:34 pm
Did some searching.  Some of those non-contact overhead line detectors were good into the 400KV+ in wet weather conditions and safe.   

IEC 61243-1: Live working - Voltage detectors - Part 1: Capacitive type to be used for voltages exceeding 1kV a.c.
IEC 61243-2: Live working - Voltage detectors - Part 2: Resistive type to be used for voltages of 1kV to 36kV a.c.
IEC 61243-3: Live working - Voltage detectors - Part 3: Two-pole low-voltage type
IEC 61243-6:2017(E)  portable non-contact voltage detectors

I may look into getting 1-6.  It's pretty interesting stuff. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on July 28, 2017, 12:59:08 am
Did some searching.  Some of those non-contact overhead line detectors were good into the 400KV+ in wet weather conditions and safe.   

IEC 61243-1: Live working - Voltage detectors - Part 1: Capacitive type to be used for voltages exceeding 1kV a.c.
IEC 61243-2: Live working - Voltage detectors - Part 2: Resistive type to be used for voltages of 1kV to 36kV a.c.
IEC 61243-3: Live working - Voltage detectors - Part 3: Two-pole low-voltage type
IEC 61243-6:2017(E)  portable non-contact voltage detectors

I may look into getting 1-6.  It's pretty interesting stuff.

Speaking of non-contact voltage detectors (even cheap ones), what are the possible dangers of using those, e.g. is there a chance of some arcs crossing over to it during high voltage spikes?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on August 08, 2017, 10:25:46 pm
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.
 The meter used in Dave's review appears to read normally.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: FrankBuss on August 08, 2017, 11:17:59 pm
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.

I got my AN8008 last week and can confirm this, it shows only 0 when below +/-5uV. Have to do a better setup, maybe Dave can test this, too, it is jumping a bit. Additionally it feels like it has a little bit of hysteresis, so when dialing it down from 10uV to -10uV, it stays longer at 0uV until it jumps to some value less than -5uV.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: retrolefty on August 08, 2017, 11:46:37 pm
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.

I got my AN8008 last week and can confirm this, it shows only 0 when below +/-5uV. Have to do a better setup, maybe Dave can test this, too, it is jumping a bit. Additionally it feels like it has a little bit of hysteresis, so when dialing it down from 10uV to -10uV, it stays longer at 0uV until it jumps to some value less than -5uV.

 Very interesting. We did similar in digital process control to quite down zero flow/pressure/level/etc. It was an optional parameter but the console operators seemed to prefer nice straight lines.   :-//
if i recall properly I think the parameter was named CLAMPING
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Mark Hennessy on August 09, 2017, 01:47:42 am
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.

I got my AN8008 last week and can confirm this, it shows only 0 when below +/-5uV. Have to do a better setup, maybe Dave can test this, too, it is jumping a bit. Additionally it feels like it has a little bit of hysteresis, so when dialing it down from 10uV to -10uV, it stays longer at 0uV until it jumps to some value less than -5uV.

Several people have picked up on this, but I don't think anyone has mentioned that the AN8002 and AN860B+ do it as well. These meters have less resolution, so it's +/-50uV in their case. This +/-5 LSB behaviour is clearly a function of the IC, but I wonder if it can be altered via the EEPROM?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: deflicted on August 09, 2017, 03:41:11 am
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.

I got my AN8008 last week and can confirm this, it shows only 0 when below +/-5uV. Have to do a better setup, maybe Dave can test this, too, it is jumping a bit. Additionally it feels like it has a little bit of hysteresis, so when dialing it down from 10uV to -10uV, it stays longer at 0uV until it jumps to some value less than -5uV.

Several people have picked up on this, but I don't think anyone has mentioned that the AN8002 and AN860B+ do it as well. These meters have less resolution, so it's +/-50uV in their case. This +/-5 LSB behaviour is clearly a function of the IC, but I wonder if it can be altered via the EEPROM?

I'm an electronics newb, so forgive me if this is a dumb question, but is this possibly an intentional deadband that they put in there due to excessive ADC jitter in that region? I deal with stuff like that on the software side of things at work, but I'm not an EE so I only have a fuzzy understanding of what the issues are on the electrical side of things. We apply a deadband in software to some of the ADC readings we get, for that reason (too much jitter near zero). But the stuff I work on is avionics related, with the ADCs embedded in various position sensors, etc. So I'm not sure if the same thing would apply to whatever's going on inside the DMM.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 09, 2017, 03:58:49 am
I recently got an AN8008 mainly for the one microvolt resolution.  I notice that the display reads zero between the range of -5uv and +5uv.  I wonder if the manufacturer has recently done this purposely to try to hide drift.

I got my AN8008 last week and can confirm this, it shows only 0 when below +/-5uV. Have to do a better setup, maybe Dave can test this, too, it is jumping a bit. Additionally it feels like it has a little bit of hysteresis, so when dialing it down from 10uV to -10uV, it stays longer at 0uV until it jumps to some value less than -5uV.

Several people have picked up on this, but I don't think anyone has mentioned that the AN8002 and AN860B+ do it as well. These meters have less resolution, so it's +/-50uV in their case. This +/-5 LSB behaviour is clearly a function of the IC, but I wonder if it can be altered via the EEPROM?

I'm an electronics newb, so forgive me if this is a dumb question, but is this possibly an intentional "deadband" that they put in there due to excessive ADC jitter in that region? I deal with stuff like that on the software side of things at work, but I'm not an EE so I only have a fuzzy understanding of what the issues are on the electrical side of things. We apply a deadband in software to some of the ADC readings we get, for that reason (too much jitter near zero). But the stuff I work on is avionics related, with the ADCs embedded in various position sensors, etc. So I'm not sure if the same thing would apply to whatever's going on inside the DMM.
It could well be, if avionics don't require that level accuracy then I seriously doubt if most people involved in electronics do either, I expect that I'm about to get shot at here now  :scared: but sometimes I cant help but wonder if the precision of meters that go to 3 4 or 5 significant digits after the decimal point aren't like a case of more bragging rights, similar to the 0 to 62mph time of a car?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Kalvin on August 09, 2017, 04:02:01 am
It could well be, if avionics don't require that level accuracy then I seriously doubt if most people involved in electronics do either, I expect that I'm about to get shot at here now  :scared: but sometimes I cant help but wonder if the precision of meters that go to 3 4 or 5 significant digits after the decimal point aren't like a case of more bragging rights, similar to the 0 to 62mph time of a car?

Sometimes you need high dynamic range which requires more digits.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on August 09, 2017, 04:16:06 am
It could well be, if avionics don't require that level accuracy then I seriously doubt if most people involved in electronics do either, I expect that I'm about to get shot at here now  :scared: but sometimes I cant help but wonder if the precision of meters that go to 3 4 or 5 significant digits after the decimal point aren't like a case of more bragging rights, similar to the 0 to 62mph time of a car?

Sometimes you need high dynamic range which requires more digits.

Or you might want to watch a battery discharge - very small changes in voltage.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 09, 2017, 07:38:39 am
It could well be, if avionics don't require that level accuracy then I seriously doubt if most people involved in electronics do either, I expect that I'm about to get shot at here now  :scared: but sometimes I cant help but wonder if the precision of meters that go to 3 4 or 5 significant digits after the decimal point aren't like a case of more bragging rights, similar to the 0 to 62mph time of a car?

Sometimes you need high dynamic range which requires more digits.

Or you might want to watch a battery discharge - very small changes in voltage.
Is it really a requirement to watch every single mv? surely not, 5mv steps or even 10 mv steps should be enough. Don't get me wrong, I myself like to as many digits as possible, it looks very impressive but can also be a pain watching digits keep jumping back and forth when your trying measure something, so much so that at times I have to resort to my analogue meters, so much easier at times.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on August 09, 2017, 07:53:46 am
Ill be using my AN8008 to find shorts on laptop main boards by measuring voltage drops on the ground plain while applying a safe bias current to the problem rail. Although the +-5uv dead band won't be a problem in practice, I would rather it not be present.
It would be too frustrating trying to get the ebay sellers to understand and pass it back to the manufacturer.
Just hope that the manufacturer finds this thread.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on August 09, 2017, 10:21:20 am
I think that is a really good use of the uV range as you can see which traces have the largest voltage drop leading to the short.
I use a thermal imaging camera for this now.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 09, 2017, 01:59:53 pm
Is it really a requirement to watch every single mv? surely not, 5mv steps or even 10 mv steps should be enough.
First, the range we are looking at is microvolt (uV) not millivolt (mV) - but your point is still valid.

The requirement for accuracy is dependent on the circumstance.  For most day-to-day situations I encounter at under 12V, 50mV accuracy is quite good enough - but there are some occasions where I found this would be totally inadequate and I needed those smaller units of resolution.

It is to those situations where this discussion is speaking - and I, for one, am not really happy about the idea that someone has made a decision to include an arbitrary "dead spot" - especially one that is not advertised.

Call me weird, but I would much rather have the "best guess" of the meter's ADC with a large error bar than not have any idea what's going on.  For example, if it gave me a reading of 2uV with an error range of +/- 2uV, then a change from zero would tell me something is happening.  With a 5uV dead spot - you just wouldn't know.

This is the thing about test and measuring equipment - they get used in all sorts of different situations where you cannot always make design decisions in that equipment that affect fundamental expectations without at least making those very clear from the outset.

It is always useful for someone to know the limitations of their equipment - and it is essential when they start pushing into those regions.  If I had the choice in a situation like this, I would strongly lean towards having a noisy measurement than a 'cleaned up' one.  At least with the noisy one, I would see the fluctuations - which would remind me of this limitation or prompt me to check if this was normal.  With a "cleaned up" reading - I just wouldn't have any indication ... and I might spend many hours chasing a "problem" in my circuit that simply wasn't there.

I have little doubt that any "dead spot" techniques used in avionics would be specific to the task - and that the implications of doing so would have been well examined before implementing them in respect to anything that leaves the ground.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: deflicted on August 09, 2017, 04:30:50 pm
I have little doubt that any "dead spot" techniques used in avionics would be specific to the task - and that the implications of doing so would have been well examined before implementing them in respect to anything that leaves the ground.

Please keep in mind this was just me being a newb and speculating in all of my newbishness as to what might be the reason for the blind spot in the DMM, and this was based entirely on me just trying to relate what we're seeing with this DMM to a situation I'm familiar with. It was just a question, not a statement of fact, or even an attempt at an educated guess. I was just wondering aloud whether the two situations might be related somehow. I have absolutely no idea what the designers of this DMM were thinking with regard to the +/- 5uV region.

Having said that, yes, the cases where one would use a deadband in avionics are limited and problem-specific, and tend to be carefully scrutinized.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanB on August 09, 2017, 06:07:24 pm
More than one person has posted that their (non-AN8008) meter was "faulty" as it displayed fluctuating and non-zero voltages when not measuring anything. So one can imagine the manufacturers might clamp the display to zero to placate naive users and stop them complaining.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 09, 2017, 06:35:56 pm
I'm just being the devils advocate here.

With these DMM's high sensitivity to extraneous noise (induced voltages in the lower V ranges) how can you sure that what you're reading is factual or not? I'm sitting here now looking at my Philips bench meter not connected to anything apart from a set of probes and I'm getting anything from 0.51mv to 11.77mv dc depending on close I get to the meter and on VAC, I get from 0.5613V to 0.9638V. Things are much about the same with my handheld DMM's as well?

Given this, how is it possible to be certain that what you are reading is a true reflection of what is happening in the circuit your testing / working on, and not just natural background activity?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 09, 2017, 06:54:50 pm
This is where you need the skill an understanding of your environment - and the antennae you connect to the input terminals of your meter.

All too often, people blindly ignore the effect of the measuring equipment on the circuit at hand - but even more ignore the effect of the environment on the measuring equipment.

When you get into low level and high precision measurements - you have to pay attention.  Just ask any volt nut.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 09, 2017, 07:10:48 pm
I agree, but just do you null out the environmental effects? And how can you be really sure that the measurements that you see are down to the circuit only and not having environmental effects on them?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 09, 2017, 07:26:29 pm
Indeed.

The answer to that is far beyond the capability of a post on a forum - and there a far more people out there that can give better answers than I.

Understanding the basics is essential of course, but experience cannot be beaten.


You ask a good question.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: maukka on August 09, 2017, 07:42:33 pm
Got mine the other day. It's very cute and small. Seems to be accurate in the voltage ranges as well.

(http://i.imgur.com/1ruodCB.jpg)

(http://i.imgur.com/ozvZR9p.jpg)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on August 09, 2017, 07:54:53 pm
Got mine the other day. It's very cute and small. Seems to be accurate in the voltage ranges as well.

(http://i.imgur.com/1ruodCB.jpg)

(http://i.imgur.com/ozvZR9p.jpg)

Good results. :)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 09, 2017, 08:57:07 pm
Can't argue with those results can you?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on August 09, 2017, 09:13:12 pm
Can't argue with those results can you?

Pretty amazing. If we look at low voltage uses of these things, they seem to be great value.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: FrankBuss on August 09, 2017, 11:27:31 pm
Got my new Fluke 8842A, and I built a simple test circuit with two 1.5V batteries, two 1 meg resistors, a precision 10k trim pot for the offset, in parallel to one battery a 56k resistor for a smooth voltage ramp (a pot was too noisy), and a 1uF Wima film capacitor parallel to the measurement. Then no breathing or moving for 5 minutes, and I could measure this:

http://www.youtube.com/watch?v=-2Enr38UKOY (http://www.youtube.com/watch?v=-2Enr38UKOY)

+/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I know, I really have to clean up my workbench :=\
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JanJansen on August 10, 2017, 12:49:28 am
The crocodile cables that are include break off after measuring about 100 capacitors, the screw-able cables are worthless,
Now i have to look to proper crocodile cables, do they all fit in ?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: metrologist on August 10, 2017, 01:58:11 am
Got my new Fluke 8842A, and I built a simple test circuit with two 1.5V batteries, two 1 meg resistors, a precision 10k trim pot for the offset, in parallel to one battery a 56k resistor for a smooth voltage ramp (a pot was too noisy), and a 1uF Wima film capacitor parallel to the measurement. Then no breathing or moving for 5 minutes, and I could measure this:


+/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I know, I really have to clean up my workbench :=\

Now I am envious, you actually have space to set your meter on the bench without balancing and other things sliding off... Sadly, I looked for that Fluke after Dave's video. The 8008 did not come.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: retrolefty on August 10, 2017, 02:34:31 am
Quote
If I had the choice in a situation like this, I would strongly lean towards having a noisy measurement than a 'cleaned up' one.  At least with the noisy one, I would see the fluctuations - which would remind me of this limitation or prompt me to check if this was normal.  With a "cleaned up" reading - I just wouldn't have any indication ...

 In our industrial DCS systems in a refinery, a tech could call up the 'raw reading' signal reading to disable any 'zero clamping' filtering on the sensor reading being looked at. Operators liked nice quite zero readings and techs liked to see the actual noise on live signals if they wished, win...win.


Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 10, 2017, 05:54:40 pm
Operators liked nice quite zero readings and techs liked to see the actual noise on live signals if they wished, win...win.

That is exactly where my thinking lies.  For the operator, the zero null would be adequate, but the techs have the same interest that I do.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 10, 2017, 06:45:03 pm
Got my new Fluke 8842A, and I built a simple test circuit with two 1.5V batteries, two 1 meg resistors, a precision 10k trim pot for the offset, in parallel to one battery a 56k resistor for a smooth voltage ramp (a pot was too noisy), and a 1uF Wima film capacitor parallel to the measurement. Then no breathing or moving for 5 minutes, and I could measure this:

http://www.youtube.com/watch?v=-2Enr38UKOY (http://www.youtube.com/watch?v=-2Enr38UKOY)

+/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I know, I really have to clean up my workbench :=\
That update is so s l o w though that I can't help but feel that if the extra digits are that important, (in certain situations I can see that they could be) then for them to be meaningful, especially if you needed to interact with the device under test when a critical point was reached at all, that you need the update speed of the bench meter at least? At the moment it is lagging badly behind and what ever the point that you needed to interact with it, to possibly switch off to prevent damage to the project etc being developed and tested, that it would be too late anyway.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on August 10, 2017, 07:05:39 pm
Got my new Fluke 8842A, and I built a simple test circuit with two 1.5V batteries, two 1 meg resistors, a precision 10k trim pot for the offset, in parallel to one battery a 56k resistor for a smooth voltage ramp (a pot was too noisy), and a 1uF Wima film capacitor parallel to the measurement. Then no breathing or moving for 5 minutes, and I could measure this:

http://www.youtube.com/watch?v=-2Enr38UKOY (http://www.youtube.com/watch?v=-2Enr38UKOY)

+/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I know, I really have to clean up my workbench :=\
That update is so s l o w though that I can't help but feel that if the extra digits are that important, (in certain situations I can see that they could be) then for them to be meaningful, especially if you needed to interact with the device under test when a critical point was reached at all, that you need the update speed of the bench meter at least? At the moment it is lagging badly behind and what ever the point that you needed to interact with it, to possibly switch off to prevent damage to the project etc being developed and tested, that it would be too late anyway.

If speed is more important than accuracy, perhaps an automated system might be best, that switches off the project at certain value. Otherwise, you have your own reaction time to factor in.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: FrankBuss on August 10, 2017, 08:56:58 pm
Got my new Fluke 8842A, and I built a simple test circuit with two 1.5V batteries, two 1 meg resistors, a precision 10k trim pot for the offset, in parallel to one battery a 56k resistor for a smooth voltage ramp (a pot was too noisy), and a 1uF Wima film capacitor parallel to the measurement. Then no breathing or moving for 5 minutes, and I could measure this:

http://www.youtube.com/watch?v=-2Enr38UKOY (http://www.youtube.com/watch?v=-2Enr38UKOY)

+/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I know, I really have to clean up my workbench :=\
That update is so s l o w though that I can't help but feel that if the extra digits are that important, (in certain situations I can see that they could be) then for them to be meaningful, especially if you needed to interact with the device under test when a critical point was reached at all, that you need the update speed of the bench meter at least? At the moment it is lagging badly behind and what ever the point that you needed to interact with it, to possibly switch off to prevent damage to the project etc being developed and tested, that it would be too late anyway.

I don't think it is lagging behind. The update rate of the AN8008 looks like more than 1 sample per second, but it might have an offset. That's tricky, you can't tell it has an offset by shorting the leads, because of the dead spot.

The Fluke can be changed to insane speed (manual says 33 samples per second for this range) which you can't read anymore, if you need only 1 uV resolution instead of 0.1 uV, which can be very useful in combination with GPIB and automated measurements.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 10, 2017, 11:38:32 pm
Well compared to your Fluke it is certainly lacking on some occasions it is very noticeable indeed.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 11, 2017, 10:50:25 am
I couldn't get much past this...
Well compared to your Fluke .....
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on August 11, 2017, 10:54:40 am
[snippet]

...  +/-5uV deadband confirmed, but no hysteresis. I would say it is perfect for 10uV resolution for this price.

I do see hysteresis on the DCV function, but not noticable on uV. I observe it needs to read a value one or two counts over the present reading before it updates the display.

I can see the AN8008 meter uses a slow and fast filter in software, for display. The slow filter is ~2seconds. The fast is msec I'm guessing.
For fast changing signals, the meter uses the fast filter's value and if/when the derivative settles, it switches to displaying the slow-filter's value.
If you quickly connect the probes from 0V to 5.000V, it sometimes grabs (fast filter value) 4.930V and after 2 seconds goes to show (slow filter value) 5.000V
For quick changes slow filter gets "primed" by the fast filter, to speed display response time.
It's not perfect but works well enough if you wait.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on August 11, 2017, 11:01:10 am
I couldn't get much past this...
Well compared to your Fluke .....

Actually, it's not far off.
 
In china they are envious of Fluke multimeters, considered the ultimate, like owning Gucci or Mercedes but far too expensive for the masses. They are after them...
Reading the chinese forums, these multimeters appear to be a result of communism.

The government mandated the need for low-cost precision multimeters, in order to improve the nation.
The result is planning and fab of single-chip DMM IC's, which make these low dollar meters possible.
There is great national pride in this accomplishment. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on August 11, 2017, 07:14:58 pm
I couldn't get much past this...
Well compared to your Fluke .....
I'm not sure what you're saying here but from my part it was a  typo, it should read "Well compared to your Fluke, it is lagging, on some occasions it is very noticeable indeed."

To my mind the extra digit is very useful in tracking down short circuits as it allows the user to see if they moving towards or away from the location of the short and in that context the update speed is not so critical.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on August 11, 2017, 09:53:18 pm
It's simple.

Comparing a Fluke to a $25 el cheapo is a great way for me to not take great interest in the rest of the sentence.


Probably an over-reaction, so I'm sorry for that.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: b_force on August 12, 2017, 11:57:45 pm
It's simple.

Comparing a Fluke to a $25 el cheapo is a great way for me to not take great interest in the rest of the sentence.


Probably an over-reaction, so I'm sorry for that.
Don't see why Fluke needs to be the holy God here?
Just use multimeters (or any kind of equipment) for what it's good for.

So there are enough situations that you perfectly can compare a $25 meter with a Fluke.
In some situations the Fluke will be less, in others a $25 multimeter will be less.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: _roger_ on August 25, 2017, 09:08:38 pm
hello, just a little information.

IS possible has min/max or peak function?Link of mod? :D
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on August 25, 2017, 09:34:21 pm
hello, just a little information.

IS possible has min/max or peak function?Link of mod? :D
AN8002 can be modified to have extra buttons. The same modifications did not work with AN8008.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: _roger_ on August 25, 2017, 10:19:42 pm
So is not possible a mod to have peak function? :(
thanks for the info man
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: PeteAU on September 02, 2017, 09:22:56 pm
I jumped on the AM8008 bandwagon and had some issues. It was showing 300-something volts when measuring 3.3DCV signal.
Anyone else had this problem? Pressing down on the range switch seems to have fixed it (for now?)...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on September 02, 2017, 09:26:59 pm
I've had some problems with wrong measurement and missing function. They were always caused by misaligned contacts on the dial. They may get misaligned when opening and modifying the unit.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on September 04, 2017, 10:48:53 am
My AN8008 died and couldn't do ohms. Either the decimal point jumped around constantly or getting wandering 40-60ohms with input jack shorted. Test leads are ok. Checked all soldering re-did PTC but same problem.

Looks like oxide on the rotary switch contacts, spun it back and forth a few times and it's ok for now.

Gold on the PCB with copper alloy for the wiper, I guess the metal is crap, or the Krytox lube I used is causing troubles.


Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on September 04, 2017, 02:04:45 pm
I caved.

For the $22.62 it cost me (with a 2-4 week wait) it's not going to sink the ship.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 04, 2017, 03:09:47 pm
For all of the good it is not likely to do, I have queried an ebay seller about the AN8008's  +/-5uV dead spot.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: janengelbrecht on September 07, 2017, 05:32:54 am
I use this crappy shit instead. It do its job...all I need in general :)

http://www.fluke.com/fluke/iden/digital-multimeters/compact-multimeters/fluke-101-digital-multimeter.htm?PID=77003 (http://www.fluke.com/fluke/iden/digital-multimeters/compact-multimeters/fluke-101-digital-multimeter.htm?PID=77003)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 07, 2017, 05:44:22 am
For all of the good it is not likely to do, I have queried an ebay seller about the AN8008's  +/-5uV dead spot.

What do you expect to find out from a seller? They just pile 'em high and sell 'em.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 07, 2017, 06:49:35 am
For all of the good it is not likely to do, I have queried an ebay seller about the AN8008's  +/-5uV dead spot.

What do you expect to find out from a seller? They just pile 'em high and sell 'em.
Can only hope that it gets back to the manufacturer. I realize that the seller is likely to have no idea of what I'm asking about.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: metrologist on September 07, 2017, 12:00:42 pm
For all of the good it is not likely to do, I have queried an ebay seller about the AN8008's  +/-5uV dead spot.

What do you expect to find out from a seller? They just pile 'em high and sell 'em.
Can only hope that it gets back to the manufacturer. I realize that the seller is likely to have no idea of what I'm asking about.

This is actually a good play. The seller will likely see the query and immediately have a sinking in their heart. They may then send you an apologetic message begging forgiveness and give you the mean tortuous overlord spiel and offer you a measly two dollar refund in exchange for positive feedback, to avoid the beatings you know...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 07, 2017, 01:16:10 pm
For all of the good it is not likely to do, I have queried an ebay seller about the AN8008's  +/-5uV dead spot.

What do you expect to find out from a seller? They just pile 'em high and sell 'em.
Can only hope that it gets back to the manufacturer. I realize that the seller is likely to have no idea of what I'm asking about.

This is actually a good play. The seller will likely see the query and immediately have a sinking in their heart. They may then send you an apologetic message begging forgiveness and give you the mean tortuous overlord spiel and offer you a measly two dollar refund in exchange for positive feedback, to avoid the beatings you know...
I should have explained more. I sent the query to another seller, not the one I bought the original meter from.
The +/-5uV dead spot doesn't bother me much. I'd rather that the dead spot was not present.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on September 16, 2017, 04:00:25 pm
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008, a.k.a ZT109
http://zotektools.com/products-2/zt109/ (http://zotektools.com/products-2/zt109/)
But they do not make this generally known.

(http://www.eevblog.com/forum/blog/eevblog-1007-is-a-$25-multimeter-any-good/?action=dlattach;attach=351592;image)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 16, 2017, 09:30:38 pm
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: EEVblog on September 16, 2017, 10:12:43 pm
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

They want to pay me to review their new product  ::)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 16, 2017, 10:22:57 pm
They want to pay me to review their new product  ::)

Is that the one where they make a meter with milliamp and temperature ranges so that everybody who just bought a couple of AN8008s will have to go out and buy some more meters?

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on September 16, 2017, 11:31:56 pm
They want to pay me to review their new product  ::)

Is that the one where they make a meter with milliamp and temperature ranges so that everybody who just bought a couple of AN8008s will have to go out and buy some more meters?

Or maybe it's time for 20 000 counts.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: retrolefty on September 16, 2017, 11:34:49 pm
They want to pay me to review their new product  ::)

Is that the one where they make a meter with milliamp and temperature ranges so that everybody who just bought a couple of AN8008s will have to go out and buy some more meters?

 I hope so.  :-+
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Kalvin on September 16, 2017, 11:45:45 pm
My AN8008 died and couldn't do ohms. Either the decimal point jumped around constantly or getting wandering 40-60ohms with input jack shorted. Test leads are ok. Checked all soldering re-did PTC but same problem.

Looks like oxide on the rotary switch contacts, spun it back and forth a few times and it's ok for now.

Gold on the PCB with copper alloy for the wiper, I guess the metal is crap, or the Krytox lube I used is causing troubles.
I have two AN8008s, and the second one had exactly the same symptoms showing fluctuating high resistance values in ohms range [even when input probes were short-circuited]. I haven't used any lubes of any other chemicals, so it looks that the rotary switch contacts may have some oxidation problems due to material selection. Anyway, spinning the dial back and forth a few times solved the problem for now.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on September 17, 2017, 01:03:04 am
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

They want to pay me to review their new product  ::)

They should be careful what they wish for.....   (paid or not).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on September 17, 2017, 05:19:06 am
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

They want to pay me to review their new product  ::)

They should be careful what they wish for.....   (paid or not).

They probably saw the AN8008 review, and found some positive points mentioned.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: MacMeter on September 17, 2017, 05:26:00 am
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

They want to pay me to review their new product  ::)

Google foo, took me to Zorek as the maker long ago. So can you say what the new "product" might be?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on September 17, 2017, 05:49:57 am
For 8008:
http://zotektools.com/products-2/zt109/ (http://zotektools.com/products-2/zt109/)
"Passed a two-meter drop test, anti-fracture bracket"

It shows on other models, too.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on September 17, 2017, 08:28:12 am
I have been contacted by  Zotek who claim to be the original designer and manufacturer of the AN8008

What did they say?  :popcorn:

They want to pay me to review their new product  ::)

It seems like a way to get marketing and product exposure.
The fake 61010 claims and poor quality make me ask, how low to go.
Oh wow 10,000 counts and the the rotary switch oxidizes after a couple weeks  :-DD
It's like cheap candy. After the sugar buzz, you faint.

Get a box of them for joeqsmith ;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 18, 2017, 06:57:30 pm
I received a reply from Zotek about the dead spot issue on the millivolt range.
"Thank you for your support to our products. ZT109 can measure voltage larger than 20uV."
This indicates to me that the ZT109 has a +/-20uv dead spot. This would bother me.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 18, 2017, 10:12:17 pm
This indicates to me that the ZT109 has a +/-20uv dead spot. This would bother me.

You buy a $20 meter then can't sleep at night because it has a +/-20uv dead spot? Schadenfreude.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 18, 2017, 10:20:02 pm
This indicates to me that the ZT109 has a +/-20uv dead spot. This would bother me.

You buy a $20 meter then can't sleep at night because it has a +/-20uv dead spot? Schadenfreude.
I didn't buy that meter. The meter I did buy, the AN8008, has a +/-5uv dead spot. This isn't a practical problem for what I use it for.
A +/-20uv dead spot could be a problem for what I use the meter for.
The dead spot has been intentionally programmed into the meter.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on September 19, 2017, 03:17:10 am
The uV deadband seems to be about the DMM IC's quality.

A/D converter and input amp noise, and offset limit the bottom end. Then there is the reference noise also affecting the measurement low end.
The HY12P65 datasheet best is 10uV offset and 2uV noise but some people say the chip-on-board package is lower quality compared to the QFP packaged part.
COB noise is worse, and noise-ranked parts are out there.

So the firmware clips off and filters the uV noise, that seems to be the real "technology" here.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 19, 2017, 04:02:42 am
We need to step back and look at the forest. At the end of the day it's a $20 meter.

Complaining about stuff like this seems like saying "I bought a Ford Fiesta and it can't even tow a 5000lb boat (can you believe it??)"

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: IanMacdonald on September 19, 2017, 04:05:44 am
You buy a $20 meter then can't sleep at night because it has a +/-20uv dead spot? Schadenfreude.

For that price I'm expecting a Higgs detector.  :-DMM

Seriously it's a damn good meter for the money, though temperature would be handy and I'd pay a bit more to have that. Save carrying two meters. 
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on September 19, 2017, 06:27:59 am
For that price I'm expecting a Higgs detector.  :-DMM

And powered by dilithium crystals.

Seriously it's a damn good meter for the money, though temperature would be handy and I'd pay a bit more to have that. Save carrying two meters.

It's OK, but nothing special apart from the price.

The missing mA range is a bummer I don't see how people can lose sleep over a dead spot in the uV range but not worry about lack of mA. The square wave output is a waste of a selector switch position IMHO.

I actually prefer using my AN860B+ to my AN8008 even though it's bigger. The AN8008 feels really cheap and plasticky in comparison.

I've got my fingers crossed that the AN8008 is just a clever marketing move to sell a load of meters and the 'AN8009' will be the real multimeter - the meter that everybody wanted in the first place, ie. with temperature, mA and the missing REL/MIN/MAX buttons built in. We know the chipset can do it...  :popcorn:

Size-wise, I'd like it to be a little bit bigger than the AN8008. The selector switch could stick out a bit more at the ends instead of having them rounded off into the dial, too.

Also: The AN8008 screen contrast needs a lot of work and the backlight is pathetic.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: xavier60 on September 19, 2017, 09:26:35 am
Regardless of the low price of these meters, the dead spot is present due to manufactures' choice.
The 1uv resolution is very useful to me for finding shorts on laptop main boards by tracing ground plane voltage drops,
by comparing quick readings.
A slow zero offset drift is no problem. A large +/-20uv dead spot could be a problem. Offset drift will be adding or subtracting to this dead spot.
The AN8008 in Dave's review doesn't seem to have any dead spot.
I didn't buy the AN8008 just because it was cheap. I mainly use Fluke 87V DMMs.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: plazma on October 27, 2017, 05:29:04 pm
New AN8009 version coming to Banggood
https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html (https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Mark Hennessy on October 27, 2017, 08:00:36 pm
Interesting...

This one adds:

+ Temperature (interesting probe, looks better than the usual exposed bead type)
+ 99.9Mohm range (the 9.99M of the AN8008 is a pain)
+ NCV detection (I don't use this much on DMMs, preferring a dedicated volt-stick, but the chip supports it, so why not?)

And removes:

- Square wave generator. Not a loss IMHO, but others might miss it.

But no changes to the current ranges. An opportunity wasted, sadly - personally I would have preferred them to use the switch position for a mA range rather than the NCV function, but can only assume it was easier for them to do what they've done. Oh well - roll on AN8010 ;)

I'll certainly pick one of these up. I also have a BSIDE ZT301 on the way, so will be adding these to my reviews (along with another half-dozen meters that have arrived since the last update).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on October 27, 2017, 08:23:55 pm
New AN8009 version coming to Banggood
https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html (https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html)

With zipper case, NCV and temperature probe. Cool.

I can hear a million AN8008 owners preparing to buy more meters.

(Still no 10mA/100mA ranges though. Or Rel button. Maybe they'll be in the next version, right? The ANENG marketing department is truly the Apple of the multimeter world  :popcorn: )
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Mark Hennessy on October 27, 2017, 09:33:11 pm
I can see that case being used with other meters - it's far too big for the AN8009. From the photo, it looks pretty good for a freebie...

Hopefully the meter will be available without all the accessories for less money.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on October 27, 2017, 10:57:17 pm
I can see that case being used with other meters - it's far too big for the AN8009.

Looks like the meter would fit in sideways.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kerrsmith on November 10, 2017, 03:08:07 am
Just thought I would mention that Banggood currently have the ANENG AN8008 multimeter on offer with a 25% discount making it about 14 UK pounds:

https://www.banggood.com/ANENG-AN8008-True-RMS-Digital-Multimeter-AC-DC-Current-Voltage-Resistance-Frequency-Capacitance-Test-p-1157985.html?p=2D100314686672015046 (https://www.banggood.com/ANENG-AN8008-True-RMS-Digital-Multimeter-AC-DC-Current-Voltage-Resistance-Frequency-Capacitance-Test-p-1157985.html?p=2D100314686672015046)

This seems to be a really good price for this meter and is the lowest I have seen it - I am always checking their latest deals and this one looks great.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on November 10, 2017, 03:13:51 am
Just thought I would mention that Banggood currently have the ANENG AN8008 multimeter on offer with a 25% discount making it about 14 UK pounds:

They just released the AN8009 so that's to be expected.

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kerrsmith on November 10, 2017, 10:20:23 pm
Just thought I would mention that Banggood currently have the ANENG AN8008 multimeter on offer with a 25% discount making it about 14 UK pounds:

They just released the AN8009 so that's to be expected.

I had not seen this new model - thanks for letting me know about it. I recently bought the Aneng AN860B+ after reading the reviews on the following site about it:

https://www.markhennessy.co.uk/budget_multimeters/aneng_an860bplus.htm (https://www.markhennessy.co.uk/budget_multimeters/aneng_an860bplus.htm)

I also bought a cheapish voltage reference (AD584) to test my multimeters with and this new one was spot on compared to the 'data sheet' that came with the reference.

I always find it quite tricky to decide on what version of a new bit of equipment to buy when there are multiple subtle differences between them so when meters are at these prices it is not too hard a decision to just get more than one.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on November 10, 2017, 10:30:10 pm
They just released the AN8009 so that's to be expected.

I had not seen this new model

It's only just been released

I recently bought the Aneng AN860B+ after reading the reviews on the following site about it:

I'm a fan of the 860B+.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: JXL on November 12, 2017, 11:33:14 am
New AN8009 version coming to Banggood
https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html (https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html)

Ordered the AN8009 after I saw this.  Arrived today.  Temperature measurements in C and F in whole numbers only.  100Mohm range works.  Same 5uV deadband as AN8008.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Brumby on November 12, 2017, 11:52:39 am
Ordered the AN8009 after I saw this.  Arrived today. 
:-+

Quote
Temperature measurements in C and F in whole numbers only. 
Unfortunate - but, for the number of times I would use it, not a deal breaker.

Quote
100Mohm range works. 
Nice, but I can't remember the last time I measured above 5M - and if I want to do insulation testing, I'd like a few more volts behind it.  There will be some who will find this useful, though.

Quote
Same 5uV deadband as AN8008.
Seems I'll just keep to my AN8008 then.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kerrsmith on November 17, 2017, 09:00:40 pm
The new ANENG AN8009 is currently on offer on Banggood for 15.42 UK pounds:

https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html?p=2D100314686672015046 (https://www.banggood.com/ANENG-AN8009-True-RMS-NCV-Digital-Multimeter-9999-Counts-Backlight-AC-DC-Current-Voltage-Tester-p-1216900.html?p=2D100314686672015046)

This is quite a bit lower than on other sites at the minute and looks like it is part of their 'Black Friday' sale. As this item is on offer you can not use any points or coupons on it but the price is still pretty good.

I have been using my ANENG AN860B+ quite a bit in the couple of weeks I have had it and I am really happy with it. Until now I have been using some much cheaper multimeters which worked perfectly well but I recently needed to calibrate a temperature sensor and they did not have enough resolution on the voltage range to get it quite right.

I also saw that the ANENG AN8008 is still on offer:

https://www.banggood.com/ANENG-AN8008-True-RMS-Digital-Multimeter-AC-DC-Current-Voltage-Resistance-Frequency-Capacitance-Test-p-1157985.html?p=2D100314686672015046 (https://www.banggood.com/ANENG-AN8008-True-RMS-Digital-Multimeter-AC-DC-Current-Voltage-Resistance-Frequency-Capacitance-Test-p-1157985.html?p=2D100314686672015046)

I actually bought this the other day as I had quite a few points available and they made it just over 11 UK pounds. I have been looking at the differences between this and the new version and they are very similar but the new one has a resistance range up to 99.99M ohms and it also measures temperature. The older version does have a square wave output function though which could be handy sometimes.

My poor old multimeters which have served me so well for years are now slowly getting pushed further back in the draw where I keep them as my new ones arrive.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: DavisLV on November 23, 2017, 10:37:16 am
Has anyone tested AN8009 in lab conditions (with precise calibration references and/or high-end reference meter) - is it as precise as AN8008?
And what about precision of the 100M range?
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tzok on November 25, 2017, 09:48:54 am
I've noticed that my AN8008 has some small GUI bug - when I press range switch for a first time, the display changes from AUTO to MANUAL, but when I press it for a second time the MANUAL disappears from the screen and never reappears again as long as meter stays in MANUAL mode. Also there seems to be no way to go back to AUTO mode other than by changing function or DC/AC mode.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kerrsmith on November 29, 2017, 01:15:02 am
I've noticed that my AN8008 has some small GUI bug - when I press range switch for a first time, the display changes from AUTO to MANUAL, but when I press it for a second time the MANUAL disappears from the screen and never reappears again as long as meter stays in MANUAL mode. Also there seems to be no way to go back to AUTO mode other than by changing function or DC/AC mode.

I have watched quite a few Youtube videos on this multimeter and have seen this mentioned several times. It seems to be that once in manual range mode you need to physically move the dial to get out of it as you have noticed yourself. I guess it could be called a bug (or maybe a missing feature?) as it would be handy to toggle the manual range mode on and off but for me I just turn the dial to reset it.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tzok on November 29, 2017, 04:11:31 am
It seems to be that once in manual range mode you need to physically move the dial to get out of it as you have noticed yourself. I guess it could be called a bug (or maybe a missing feature?)
By bug, I meant the fact, that MANUAL sign disappears after changing range with RANGE button.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Old Don on November 29, 2017, 05:53:00 am
I just received my AN8009 and am a bit disappointed in it since even my free Harbor Freight CenTech has a transistor tester and came with batteries.  >:D

Really, I did just get a AN8009 to use as a backup to my Flute when it's got itself lost on the workbench. They really do need to add a "locate meter" function for meters in general! Other than putting batteries into it and seeing if the functions appear to work I haven't used it. Test leads are about of the same quality level as the CenTech and so will be limited to low voltage usage. The plastics used for the case will not stand up to hard knocks and offering a slip on rubber boot as as an option would add hopes of it surviving drops. Guess that would double the cost? Since I don't intend to attempt to drive nails with my meter I guess the case represents low cost and also answers the question -- what the heck did you expect for $20 US including shipping?

Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Herkatus on December 01, 2017, 10:16:50 am
Hello,

I've looking for a while for a cheap multimeter for small DIY projects. Nothing special.

I've read several reviews and I come up with the following shortlist:


If they were all $20-$25, which one should I pick?

Thanks in advance
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on December 01, 2017, 11:44:43 am
I've looking for a while for a cheap multimeter for small DIY projects. Nothing special.
  • Aneng AN860B+
  • Aneng AN8009
  • BSIDE ZT301
  • UNI T UT139C
If they were all $20-$25, which one should I pick?

ANENG AN860B+

Edit:
ZT301: Would be my second choice but I like the solid built, rubbery AN860B+ more (plus AN860B+ is cheaper).
AN8009: No proper milliamp ranges, tiny custom fuses (10mmx3mm - good luck finding replacements!)
UT139C: It's twice as expensive as the others and not really any better.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kalel on December 01, 2017, 11:58:31 am
I've looking for a while for a cheap multimeter for small DIY projects. Nothing special.
  • Aneng AN860B+
  • Aneng AN8009
  • BSIDE ZT301
  • UNI T UT139C
If they were all $20-$25, which one should I pick?

ANENG AN860B+

Having one, I would also recommend it. However, I haven't actually had/tried the others.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: kerrsmith on December 02, 2017, 01:29:21 am
I have both the Aneng AN860B+ and the Aneng AN8008 (I know you mentioned the Aneng AN8009 but I have not bought this one yet) and I really like them both. I like the AN860B+ as it is a great size and has a really big display, the Aneng AN8008 is smaller but has a higher count, 9999 count versus 6000 for the AN860B+. I would not use either for mains or high voltage work but as I do not do this kind of thing it is not an issue for me.

If you want a detailed description of them then I recommend the following reviews:

https://www.markhennessy.co.uk/budget_multimeters/aneng_an8008.htm (https://www.markhennessy.co.uk/budget_multimeters/aneng_an8008.htm) for the Aneng AN8008 version
https://www.markhennessy.co.uk/budget_multimeters/aneng_an860bplus.htm (https://www.markhennessy.co.uk/budget_multimeters/aneng_an860bplus.htm) for the Aneng AN860B+ version

I ended up getting both (and probably will get more) as they are really great value - if you are not sure which one to get just pick one and at a later date, when they go on offer again, just get the other one - this is what I did. It is always useful to have two or more meters, I think Dave says four is a good number...
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Herkatus on December 02, 2017, 09:50:11 am
Thank you for all you input. I bought the AN860B+
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: casinada on December 13, 2017, 03:46:50 pm
SURPEER 20000 Counts costs $29.99 shipped now. Does it put it back on the race for best bang for the buck in the extra cheap DMM category?   :-//
https://www.amazon.com/gp/product/B071H8PR61/ref=ox_sc_act_title_1?smid=A4Y1P2CGCCEXO&psc=1 (https://www.amazon.com/gp/product/B071H8PR61/ref=ox_sc_act_title_1?smid=A4Y1P2CGCCEXO&psc=1)

The equivalent HY-19E costs $39.99 in Banggood.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on December 13, 2017, 03:57:39 pm
SURPEER 20000 Counts costs $29.99 shipped now. Does it put it back on the race for best bang for the buck in the extra cheap DMM category?   :-//
https://www.amazon.com/gp/product/B071H8PR61/ref=ox_sc_act_title_1?smid=A4Y1P2CGCCEXO&psc=1 (https://www.amazon.com/gp/product/B071H8PR61/ref=ox_sc_act_title_1?smid=A4Y1P2CGCCEXO&psc=1)

The equivalent HY-19E costs $39.99 in Banggood.
Looks very similar to this one:
https://www.aliexpress.com/item/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/32821199756.html (https://www.aliexpress.com/item/ZEAST-282-20000counts-Digital-Multimeter-True-RMS-4-1-2-Auto-Range-Voltmeter-Current-Ohm-Resistance/32821199756.html)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Mr. Scram on December 13, 2017, 11:33:43 pm
The SURPEER seems to have a bargraph, something I hadn't seen yet on a cheap multimeter. Too bad it's not the prettiest.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Specmaster on December 14, 2017, 12:07:51 am
The SURPEER seems to have a bargraph, something I hadn't seen yet on a cheap multimeter. Too bad it's not the prettiest.
Well I think it looks OK, display seems to be nice and clear as does the range selector but I notice that its not available for shipping to the UK, why? It's not because Amazon UK have it stock because they don't even list it so what gives there then.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on December 14, 2017, 03:48:30 am
Well, at least in the Amazon US the price buys also a "Receive 1 SURPEER Steel Stainless Coffee Grinder free when you purchase 1 or more SURPEER LCD Auto Ranging Multimeter offered by SURPEER."

For a company that "manufactures" a wide range of products from precision instrumentation equipment to coffee grinders, I think they must be the next GE!  :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: stach on December 14, 2017, 05:06:18 am
I couldn't find if this link has been posted here or not, but if you want to make Ananeg (or others which use same hardware) better read this:

https://www.jackenhack.com/aneng-an8008-modify-for-better-accuracy-faster-readings/ (https://www.jackenhack.com/aneng-an8008-modify-for-better-accuracy-faster-readings/)

Does make a difference ;)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: amspire on December 14, 2017, 10:05:58 am
The SURPEER seems to have a bargraph, something I hadn't seen yet on a cheap multimeter. Too bad it's not the prettiest.
Well I think it looks OK, display seems to be nice and clear as does the range selector but I notice that its not available for shipping to the UK, why? It's not because Amazon UK have it stock because they don't even list it so what gives there then.
I think the Zeast version on Aliexpress looks better and is probably cheaper for most people (see link in my previous post). Should be available to the UK.

It includes the bar graph, dual 4 1/2 digit displays and the NCV proximity voltage detection. It is an interesting meter even if the specifications may be a little optimistic.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: casinada on December 21, 2017, 05:06:48 pm
I missed the opportunity of the free coffee grinder on amazon since the price went up back to $39.99 for the Surpeer AV4.
I found the Zeast 282 on ebay for $28.84:
https://www.ebay.com/itm/20000counts-Multimeter-Digital-LCD-Professional-Voltmeter-Current-Tester-RMS/372140030906?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 (https://www.ebay.com/itm/20000counts-Multimeter-Digital-LCD-Professional-Voltmeter-Current-Tester-RMS/372140030906?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649)
Will see when it shows up  :)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: BillyO on January 25, 2018, 02:11:44 pm
Dave was a bit unfair to this one.  Performance wise, it literally blows the Fluke 101 away at well less than half the price.  He whined a bit much about the lack of current ranges, but ya know, I spent a few minutes looking over the Fluke 101 and couldn't find a current range at all.  How much do you have to spend on a Fluke before you get an current measurement, let alone uA and mA.  Heck, you have to go to a Fulke 115 to even get a current range, and it won't touch this.

Same quality probes, but less accessories on the Fluke.

For some dude using this in their basement with an Arduino, it is head an shoulders over anything from Fluke under $150.

I think Dave is a little split from reality.  We don't all need $2,575 multi-meters.  I'd even hazard Dave doesn't either.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: tvicol on June 04, 2018, 10:31:08 pm
My solar DMM.  8)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: floobydust on June 05, 2018, 06:38:38 am
Dave was a bit unfair to this one.  Performance wise, it literally blows the Fluke 101 away at well less than half the price.  He whined a bit much about the lack of current ranges, but ya know, I spent a few minutes looking over the Fluke 101 and couldn't find a current range at all.  How much do you have to spend on a Fluke before you get an current measurement, let alone uA and mA.  Heck, you have to go to a Fulke 115 to even get a current range, and it won't touch this.

Same quality probes, but less accessories on the Fluke.

For some dude using this in their basement with an Arduino, it is head an shoulders over anything from Fluke under $150.

I think Dave is a little split from reality.  We don't all need $2,575 multi-meters.  I'd even hazard Dave doesn't either.

Have you ever even used a high quality multimeter?   :)

This cheap and unreliable multimeter has more digits than Fluke's low end, but, if the rotary switch isn't oxidized, it's the banana jacks or test leads making poor connections.
Popped the fuse? Toss the meter in the garbage or waste time doing mods to fit a "normal" fuse.
It's unsafe for high voltage or mains work due to the fake IEC61010 approvals.

Sure, it's OK for hobbyists and the Arduino/maker crowd.
Depending on what you value the most: resolution, accuracy, safety, reliability, cost, features etc. some people will spend more on a multimeter. Not to this crazy $2,575 level you mention.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on June 05, 2018, 07:00:50 am
Dave was a bit unfair to this one.  Performance wise, it literally blows the Fluke 101 away at well less than half the price.  [...]

Popped the fuse? Toss the meter in the garbage or waste time doing mods to fit a "normal" fuse.

Popped the fuse? Just leave the burned-out fuse in there, and your Aneng comes even closer to the Fluke 101!  :P
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on June 05, 2018, 07:59:54 am
The hobbyist working on low voltages definitely does not need an incredibly safe meter, and if the temptation to use it on a household circuit can be kept at bay, there is a very high chance the meter will survive for quite a long time. So, go for it.

Even if from time to time the meter is used around in the household (but away from the circuit breaker panel), there is an incredibly low chance the meter itself will cause personal injury - still a gamble, but incredibly low. The chances the meter will be destroyed are much higher - especially with my biggest pet peeve of the super cheap meters such as this one: the quality control. While certain meters have reasonable design and ergonomics, in my experience I have *always* found one of a few problems related to quality inside brand new meters: bits and pieces of solder or tiny metallic shards; loose springs, screws or even rotary switch leads, blobs of solder that reduce creepage distances to 1mm or less; massive amounts of flux residue with impurities that also reduce dielectric resistance. Another factor that contributes to the longevity of cheap meters is the current inputs: either unfused or merged with the V range. An inadvertent flip on the switch range is enough to short very high power lines (if used around on the outlets).

A very small probability of accidents can happen with voltage surges coming from the power lines. That is quite unusual and has unpredictable consequences, but a safer meter will have more chances of preventing the user from being harmed.

With any meter, always keep in mind that accidents happen when someone is most distracted or tired or misinformed - a gamble that has less probability of having terrible consequences if the meter is safer and better built.

The way I see these evaluations is that Dave, on his position of educating and influencing the crowds, is hard pressed to provide a verdict that is based on his own experience with several brands. If the quality is not comparable, I would want to know that his "grade" would reflect that, otherwise there would be a lack of reliance in his evaluations if the standard of a well built meter is reduced to cater to the ultra low cost audience.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on June 05, 2018, 09:39:35 pm
Have you ever even used a high quality multimeter?   :)

Yes!  8)

This cheap and unreliable multimeter has more digits than Fluke's low end, but, if the rotary switch isn't oxidized, it's the banana jacks or test leads making poor connections.

Real life experience tells us that this doesn't happen as often as Fluke-owners like to think.

Secondly: If you're working with a meter every day then you'll soon know if it starts to give problems. The real problem is with cheapo borrowed meters, not the meters you own. Moral: Never use an unkown meter for critical/dangerous jobs. This applies to Flukes, too - you don't know what's inside.

If you've got two or three cheapo meters then you'll be fine for hobby work IMHO. Of course it would be nice to own three Flukes instead, no disagreement there, but that's often not realistic.

The hobbyist working on low voltages definitely does not need an incredibly safe meter, and if the temptation to use it on a household circuit can be kept at bay...

If the temptation can't be kept at bay then a Fluke 101 is a nice addition to any collection (and only costs about $45).
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: madires on June 05, 2018, 11:48:13 pm
If you like to work on mains wiring and distribution panels get a proper tool like a Duspol (similar testers are available from Fluke). A DMM is simply the wrong tool for this kind of work.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on June 06, 2018, 02:24:28 am
If you like to work on mains wiring and distribution panels get a proper tool like a Duspol (similar testers are available from Fluke). A DMM is simply the wrong tool for this kind of work.

I guess that choice depends on the ratio of mains/non-mains work.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: madires on June 06, 2018, 03:50:21 am
A Duspol Analog rated for CAT III 1000V and CAT IV 600V is about EUR 55, and it doesn't require you to be a mutant with three arms. It also has some nice features like LowZ, RCD check and phase detection. Since it doesn't measure current you can't forget to switch the probe leads back to the voltage input jack or cause other related disasters.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: ebastler on June 06, 2018, 04:14:18 am
If you like to work on mains wiring and distribution panels get a proper tool like a Duspol (similar testers are available from Fluke). A DMM is simply the wrong tool for this kind of work.

I guess that choice depends on the ratio of mains/non-mains work.

No contradiction between those two statements, in my book. If you like to work on mains wiring and do so regularly, a Duspol is a good idea. If you only work on mains a couple of times per year, nothing wrong with using the trusty multimeter which you bought for your electronics projects. Provided, of course, that the meter has decent safety, and that you use it properly.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: rsjsouza on June 06, 2018, 04:20:07 am
The hobbyist working on low voltages definitely does not need an incredibly safe meter, and if the temptation to use it on a household circuit can be kept at bay...
If the temptation can't be kept at bay then a Fluke 101 is a nice addition to any collection (and only costs about $45).
Yes, that is a nice meter indeed. However, such "temptation opportunities"  8) tend to happen at the most unexpected times, when one gets the first (or the only) meter within their reach.

A Duspol Analog rated for CAT III 1000V and CAT IV 600V is about EUR 55, and it doesn't require you to be a mutant with three arms. It also has some nice features like LowZ, RCD check and phase detection. Since it doesn't measure current you can't forget to switch the probe leads back to the voltage input jack or cause other related disasters.
These testers are really nice. For a casual hobbyist, though, it is hard to justify the cost - after all, much more capable gear can be had for a fraction.

The grandpa of these testers:  :-DD
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Fungus on June 06, 2018, 04:28:08 am
If you like to work on mains wiring and do so regularly, a Duspol is a good idea. If you only work on mains a couple of times per year, nothing wrong with using the trusty multimeter which you bought for your electronics projects. Provided, of course, that the meter has decent safety, and that you use it properly.

QFT.
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Muttley Snickers on July 20, 2018, 12:42:38 pm
For those in Australia interested Aldi have another multimeter and some other stuff on offer this coming Saturday, the meter is $20 and appears to be a Holdpeak 39B with a large 2000 count display according to the specifications. Anyway, it looks to be an improvement and slightly cheaper than the previous thing they had on offer and Banggood currently have them listed for around $26, as with any Aldi purchase always keep your receipt.

I don’t think anyone could take something back to Aldi based on the “not as described” consumer law because they are as vague as mud when it comes to product descriptions and information, perhaps this is a ploy to get customers into the store to find out what the hell the product actually is or does. I shouldn’t criticise them really as they do keep the other major players on their toes in regards to competition and pricing.

Aldi Special Products.   ::)
https://www.aldi.com.au/en/special-buys/special-buys-sat-21-july/ (https://www.aldi.com.au/en/special-buys/special-buys-sat-21-july/)

HoldPeak Meters.   :o
http://www.holdpeak.com/Product/plist/id/114/one/1/two/1.html (http://www.holdpeak.com/Product/plist/id/114/one/1/two/1.html)
Title: Re: EEVblog #1007 - Is a $25 Multimeter Any Good
Post by: Camicia on November 20, 2018, 10:11:06 pm
This  SURPEER AV4 True RMS 4.5 Digit (20000 count) Multimeter  0.05% class, CAT IV 600V rated supposedly (not certified) (http://www.eevblog.com/forum/testgear/surpeer-av4-true-rms-4-5-digit-multimeter) is $13 on amazon. It used to be $37.