EEVblog 1731 - $50 Ziboo 17B Pro Multimeter vs $150 Fluke REVIEW

[floobydust]

Are they legit fuses? Dongguan Reomax Electronics Co. Ltd. 6.600 Series 600V 6.3*32mm (1-1/4" x 1/4") 10kA. Kinda needs the logo? Same p/n for fast or slow blow? 
I couldn't find any safety certificates for them. Seems dodgy. Naive Westerner.
They mention rated voltage can be 1,000V but no mention of sand-filled but hey this is china you trust your hands and face to.


The multimeter owner's manual I could not find, so no idea about the 1,500V claim you are talking about. Nobody is stupid enough to use this on distribution power systems 300-1,000VAC.
Although it could measure to say 1,500V the problem is the MOV's start conducting and heating up. If only we knew their part number to gauge the leakage currents.

[EEVblog]

Are they legit fuses? Dongguan Reomax Electronics Co. Ltd. 6.600 Series 600V 6.3*32mm (1-1/4" x 1/4") 10kA. Kinda needs the logo? Same p/n for fast or slow blow? 
I couldn't find any safety certificates for them. Seems dodgy. Naive Westerner.

They use the Underwriters Laboratories logo on the datasheet and printed on the fuses, so presumably third party tested?
I'm not sure the UL database is publicly searchable though?

[EEVblog]

I am a bit late in watching the video, but I'm not sure I would have said the fuses were good - the meter is rated to 1500 Vdc but the fuses are only rated to 1000 Vdc.

The fuses are not used on the DC voltage range, so that DCV rating is irrelevant.

[floobydust]

Are they legit fuses? Dongguan Reomax Electronics Co. Ltd. 6.600 Series 600V 6.3*32mm (1-1/4" x 1/4") 10kA. Kinda needs the logo? Same p/n for fast or slow blow? 
I couldn't find any safety certificates for them. Seems dodgy. Naive Westerner.

They use the Underwriters Laboratories logo on the datasheet and printed on the fuses, so presumably third party tested?
I'm not sure the UL database is publicly searchable though?

Yes, I find the UL Product iQ Database is terrible, you can't actually find out what something was approved to. They want an account set up, as if you are a manufacturer needing approvals.
But I did open a case with them about these fuses, lest we be naive Westerners lol. They might be legit, or not - it's just that they provide a safety function.

Laser etched, no manufacturer logo yet an approvals logo -  I would have trouble taking those seriously. My last chinese 2A fuse purchase was doing great holding 10A   
edit: "Notice that fakes have been found frequently in the market recently. Please treat reomax Ruimai product confirmation with caution!"

The PTC's are also a safety item and would need to be checked. If on Ohms and touched 600VAC can they take it without exploding?

All this because they appropriated the Fluke model number 

[stj]

the fuses are usually only in-circuit when in current mode,
so the max fuse voltage only has to reach the max CURRENT RANGE voltage.

most people - even on this forum, dont seem to be aware that in voltage-mode all meter schematics i'v seen do not fuse the input.
also i doubt you can read current at 1500v or even 600v - there isnt enough gap around the shunt.

[Kleinstein]

The 1500 V range is only for DC volts and this would only be for a low power DC circuit. The AC maximum and CAT II rating is still only for 1000 V and thus the 1000 V rated fuses are OK (if legit).
The problem is however the lack of creep distance around the fuses and maybe the lower current shunt ( ? under the fuse). It does not help much that the fuse is good for 1000 V when the spacing on the PCB is not.

The gaps around the shunt's would only matter after the fuse is blown, but it still needs to be there for a proper safty rating. A higher voltage test with the fuse removed or a dummy blown one installed would likely fail from looks.

[Neilm]

I am a bit late in watching the video, but I'm not sure I would have said the fuses were good - the meter is rated to 1500 Vdc but the fuses are only rated to 1000 Vdc.

The fuses are not used on the DC voltage range, so that DCV rating is irrelevant.

IEC61010-2-033 requires testing for misconnection to all plug comptatible sockets. You are supposed to apply values for any rating on other compatible terminal (section 101 for measurement circuits but don't remember which subsection and can't be bothered powering the work laptop to read it). The purpose is to simulate the case of someone having the leads plugged into the current terminals and be in volmeter mode and try to make a voltmeter reading.  Unless the current jacks do not accept the same leads as the voltage terminal this would be a fail.

Given the current circuits are low impedence, the rating and quality of the fuse is all that is standing between oops and an arc flash explosion.

[Fungus]

I am a bit late in watching the video, but I'm not sure I would have said the fuses were good - the meter is rated to 1500 Vdc but the fuses are only rated to 1000 Vdc.

The meter clearly says "CAT II 1000V CAT III 600V" on the front, that's it's "rating".

It's also marked "1000V max" across the fused terminals, which matches the fuses.

It can measure up to 1500VDC, but presumably only CAT I.

[GigaJoe]

US$ 26 now , free ship , for 15B
https://www.aliexpress.com/item/4000800214175.html

[inmbolmie]

Does anybody know if these things can be calibrated?

I sent an email to the Ziboo support address and got this response:

    We currently only have the user manual and cannot provide a calibration manual. We will update the calibration method and provide it to our customers as soon as possible. Thank you for your suggestion.

Maybe not possible at all if that IC is completely OTP?

[EEVblog]

I am a bit late in watching the video, but I'm not sure I would have said the fuses were good - the meter is rated to 1500 Vdc but the fuses are only rated to 1000 Vdc.

The fuses are not used on the voltage range.
Current range is marked 1000V so matches the fuses.

[scopeman]

Dave,

Send one to Joe Smith and he will see what it takes to blow it up for sure!

Sam
W3OHM

[floobydust]

"I am writing to you from the UL Solutions Customer Care team with information regarding navigating on the Product IQ website.
For full access you are required to register for Product IQ. However, there is a version which is complimentary: https://productiq.ulprospector.com/en/search which contains basic information.

Once your registration is completed, you can populate any information you have available pertaining to the product in the search bar such as, a file number, CCN, model, or other keyword.
You can take advantage of a “Product IQ Tour”, by clicking on the link to the left side of your screen on the main page ( www.ul.com/piq ) for a quick overview of the site before beginning your search.
The UL Product IQ can be used to verify active listings of products and standards.
Please be advised that Product IQ displays public information only, is in real time and updated twice daily. Any proprietary information must be requested from the Applicant, (owner) of the UL Solution’s file. If no information is displayed, I would suggest contacting the manufacturer of the product, or retail establishment where the product was purchased." [...]
--------------------------------------------------------

I got that response from UL Customer Care which seems to be cut'n' paste on how to navigate the Product IQ website 
As if I have time to go through all those hoops, which I did before on another product and it was disappointing and not worth it. I was asking two things - if they are Reomax fuses, and if they achieved 1,000V approvals.

Certification agencies - all they do is test and evaluate whether or not a product complies to a particular standard that the customer specifies.
They don't care about counterfeits- it costs them money to investigate that.
It's only about protecting their brand/logo (UL) where they will dig in.

Don't know if the fuses are legit or not but then again the multimeter is just as suspect as far as 61010 compliance, as it likely was never tested. ANENG got their stuff certified... as a 3V device lol.

[stj]

i looked into UL a couple of years ago,
it looked like they just sell stickers now with no real testing done.
no better than CE/CA crap if true.
i only pay attention to german TUV markings now.

[floobydust]

I have designed and put products through approvals under UL and CSA. Been to UL HQ in Northbrook, really impressive and that campus is huge, incredible test facilities.
They do very good, if not the best work - but it is really expensive. You can easily burn through USD $50K so small business can sink going with them unless they have experienced engineers to succeed first time through.
Many companies are not using UL in favor of the cheaper options.

The West's (loophole) problem allowing uncertified/untested products into our countries, greatly benefits china who exploit it to the max. We have no oversight for such intrusions and a certification body it ain't their job.
I find this forum is largely hobbyists who know it all but have no idea of safety/regulatory and it's impossible to educate without ruffled feathers.

The Ziboo is a great price and some HV stuff looks useful - but it appears to have PCB spacings issues thus is untested. Not acceptable when personal safety is at risk.

With joeqsmith apparently leaving the forum, I think we need a basic transient generator (test) as part of these multimeter reviews. Joe never would reveal details of his, to protect his domain I guess.
Something Dave might ponder.

[thm_w]

i looked into UL a couple of years ago,
it looked like they just sell stickers now with no real testing done.
no better than CE/CA crap if true.
i only pay attention to german TUV markings now.

Not true at all for UL Listed.

UL Listed: When products bear this Mark, it informs consumers that UL determined that the product met specific and predetermined requirements after testing representative samples. The criteria used for these tests are usually based on the Standards for Safety that UL has published and continues to improve over the years. Some features that products with this Mark can usually boast of are functional safety, use in marine environments and energy efficiency.

[EEVblog]

With joeqsmith apparently leaving the forum, I think we need a basic transient generator (test) as part of these multimeter reviews. Joe never would reveal details of his, to protect his domain I guess.
Something Dave might ponder.

I've actually been looking for a transient generator for quite some time. Preferably one that is compliant to the relevant 61010 CAT standards. Unfortunately they are still very expensive used. Not to mention they are usually big and shipping to Australia is horrendous.
If anyone knows of any decently priced I'm willing to drop a few grand on one.



Yes, Joe was always very cagy about his generator.
I could design and build one, but it's not really worth all the effort. And a compliant one would always be best anyway.

[floobydust]

Old Teseq NSG3040A I worked with was basically the price of a cheap car $25,000 plus accessories.
Test equipment for compliance is ridiculously expensive because of the low sales volumes and the output precision. Sending them off every year for cal was also ridiculously expensive when surprise upgrades needed to be done.
Then what finally pissed me off is the thing goes obsolete because a standard gets a few small changes and the box can no longer "comply" with them. Spending $25K on the $25K box for upgrades is just too much, very high cost of ownership. And it's used a few times a year at most. I did like how jr. engineers were terrified of the thing and I'm giving instructions to them about using the blast shield lol.

Should be some surplus ones out there but anything compliance-related gets stupid expensive even well past EOL. eBay still over $10K. NSG3060 is around $30K.
This all might be why there is so much untested gear out there-  it's too expensive to put it through the paces.
But even then, it's a destructive test and as the smoke clears it makes engineers scratch their head as to what went wrong lol. You need a high speed camera
I will use HV with less energy to flush out spacings violations.

joeq never revealed what he uses for the HV switch, otherwise the HV is easy enough to generate. Just need to switch in at least 6kV at many amps... That is the secret sauce really.
His tests did not properly include follow-through current. Once an arc starts you have a mains cycle to deal with behind it (hopefully lasting only a 1/2 cycle) but that is where the explosions really happen. He mentioned he'd made some 1/2 cycle follow-through box but I did not see it used. It just makes the explosions bigger if that is your thing.
Maybe electroboom could collaborate on something if he is still alive lol.

I'd just want to know if the multimeter can truly withstand a few kV transient, as they claim.

[stj]

i would use a crt lopt if you only need a few mA

if you want to switch KV you need a vacume relay - a glass device with no air in it that is actuated by a remote pump.

[EEVblog]

Old Teseq NSG3040A I worked with was basically the price of a cheap car $25,000 plus accessories.

Yes, something like an older 3040 is still very useful even it can't do the latest standard.
Rare enough in the US, let alone Australia.