Author Topic: EEVblog #1007 - Is a $25 Multimeter Any Good  (Read 70872 times)

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Offline kalel

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #100 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.
 

Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #101 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.  :-// 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline Rbastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #102 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.
http://rbastlerblog.jimdo.com/
Gamma spectrometer works. Now some yellow crystals need regenerating and testing.
 
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Offline kalel

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #103 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!
 

Offline TheAmmoniacal

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #104 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?
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Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #105 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.
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline Rbastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #106 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.
http://rbastlerblog.jimdo.com/
Gamma spectrometer works. Now some yellow crystals need regenerating and testing.
 

Offline kalel

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #107 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?
 

Offline BU508A

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #108 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:


Part 2 of this video:


“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline Rbastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #109 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.
http://rbastlerblog.jimdo.com/
Gamma spectrometer works. Now some yellow crystals need regenerating and testing.
 

Online JanJansen

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #110 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.
My ±100€ lab : old scope, peaktech 6225a, aneng 8008
 

Offline TheAmmoniacal

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #111 on: July 17, 2017, 03:58:01 am »
A very spectacular show to sell Fluke meters.
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Offline BU508A

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #112 on: July 17, 2017, 04:17:30 am »
A very spectacular show to sell Fluke meters.

Yep. Glad to see, that you are impressed.  :-+
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #113 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. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #114 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
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline ebastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #115 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.!
 

Offline Rbastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #116 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
Try to blast this one...
http://rbastlerblog.jimdo.com/
Gamma spectrometer works. Now some yellow crystals need regenerating and testing.
 

Offline TheAmmoniacal

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #117 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)
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Offline ebastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #118 on: July 17, 2017, 05:30:22 am »
 

Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #119 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?
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline Lightages

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #120 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.......
 

Offline ebastler

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #121 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...
 

Offline joeqsmith

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #122 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.   
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Online Fungus

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #123 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)
 

Online Fungus

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Re: EEVblog #1007 - Is a $25 Multimeter Any Good
« Reply #124 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/262880450911


Edit: It's a good idea to add a fuse as well :-)
« Last Edit: July 17, 2017, 06:46:06 am by Fungus »
 


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