Handheld meter robustness testing

[rsjsouza]

Here's this morning's comment for the day:

Your video actually shown that this dirt-cheap device is at very least conform with CATII/300, means it's compeletely safe to be used in electrical household.
According to spec CATII/300 it should be capable to withstand upto 2500V impulse voltage. Note that It said: impulse,  a voltage spike, not a contstant current.

Why does he feel my tests show the meter is completely safe?  People can't read, don't want to take the time to read or they just like to state their opinions no matter if they know something about it or not.     I can only guess what that last sentence means.   It's too bad these people won't post their opinions in this forum.  If you could actually get some constructive dialog (rare), it may actually help the group.

Living in modern times one can surely tell how people read things diagonally, can't comprehend a text or are simply armchair judges/commentators/etc...

[joeqsmith]

Living in modern times one can surely tell how people read things diagonally, can't comprehend a text or are simply armchair judges/commentators/etc...

It works fine if you are living in mom and dads basement playing video games and the height of your week is if you are the first person to comment on a freshly uploaded YT video.    It's pretty rare I will get good constructive criticism that could actually help.  Some of the best ones I have gotten were using the HOLD button when comparing meters and fixing the color.      

I went to look for a new quote for the day and the last one I posted was pulled.   I guess my response or posting here must have upset them.  No new good quotes today so we need to work backwards.   

I helped you by bringing you down to planet earth, use a meter within its specs and dont create mythical conditions. Next you will compare it with weather sealed devices? Dont play god, other people have brains too.

 
I assume they believe in a God/s, have a brain but just don't like me creating mythical conditions.  Am I the only one who find humor in these posts? 

[bitseeker]

... use a meter within its specs and dont create mythical conditions. Next you will compare it with weather sealed devices? Dont play god, other people have brains too.

 
I assume they believe in a God/s, have a brain but just don't like me creating mythical conditions.  Am I the only one who find humor in these posts?

They're quite humorous, indeed. "[U]se a meter within its specs and dont [sic] create mythical conditions" — where's the fun in that?

[lem_ix]

Most people like regurgitated, low attention span compliant videos with a buy or don't conclusion, many "professionals" included. Similarly they need confirmation that their el cheapo uni-t is safe(whatever that means) because they couldn't afford the "safe" fluke. Was amazed recently hearing a local electrician / electronics hobbyist saying how he uses his 5$ dmm for work instead of his 100$ Sanwa so that he doesn't destroy it 

Maybe in a few years you'll notice Darwinian evolution in your comment section 

[bitseeker]

Yeah, some people have "different" priorities.

[Crumble]

Didn't the Kasuntest you originally ran have some kind of lubrication on it? I'm actuaaly quite surprised both meters you tested seem to be near unaffected by so many cycles. I'd be worries about the vias under the wipe contacts, but given the limited wear this probably won't ever be an issue before the meter (or the user) dies.

I have bought four ZT102s and one AN8008.  None of these had any sort of lubrication that I saw.  I have not looked at that last ZT102.   I did apply some lubrication to the second ZT102's ball detents, along with swapping out the springs from the first unit to try and get the switch to have a better feel to it.  I did the same thing to the third unit. 

[...]

What is it then that you are mentioning here at 9:21 in this video? There was definitely something there.

I have disassembled mine to check for any residue, but I found the board to be completely clean. I did however use the opportunity to put a tad of grease in the detent race. There seems to have been a very minimal amount of it already present, but they supply ball bearings and steel parts that way quite often to prevent corrosion.

I really don't know what that stuff was.   It almost looks like when the board was washed that something dripped down.  Normally with grease it will not just wipe off.  It smears and it is slick.  I've seen a few where they use it and it's always been more translucent and applied around the contacts, not dripped across the board like this one.  I have not looked at that 4th unit to see if there was anything in it.

Okay, it was no lubrication then. On film it was difficult to judge (but in your defence: you did say it wiped off easily). It didn't hurt functionality as flux would.

[joeqsmith]

Okay, it was no lubrication then. On film it was difficult to judge (but in your defence: you did say it wiped off easily). It didn't hurt functionality as flux would.

I am not sure what would have been the long term effects of it, not knowing what it was.  It looked like scum from a wash system and may have had some flux residue in it.  It would explain the drip effect.  If that's what it was, I could see it causing problems.   

[Crumble]

I do remember trying to wash a PCB out of an audio amplifier in a dishwasher once after I had read this method was used in the Tektronix labs to reduce leakage on the board. It did not work... They used something which I found later to have been called "Kelite", but I have not been able to find a source for it, just a bunch of people that also did not have it.

Using ordinary dishwasher blocks (wihout salt and shine) all the flux residue on the board turned white and did not wash off, causing it to look similar to your Kasuntest. One would needed to scratch it off my PCB with a finger nail rather than wiping it, but it might still be similar stuff.

On a Dutch forum I found people that had PCBs that turned white in a similar way due to water ingress. It seems like water turns flux residue white, but only on the surface, because wettening the affected areas with isopropyl alcohol immediately removed the white effect and showed the brown colour underneath.

[joeqsmith]

A few people have been asking me about more specialized handheld meters.  One of the most common request I get is for meters with an oscilloscope function.  Not a graphing meter like the UT181A I looked at but more like the Fluke 97 but smaller.  Another area people seem to be interested in is handhelds designed for the automotive market.  TPI offers a few different ones.   

So if you are interested in seeing a more specialized meter ran, feel free to chime in.

[joeqsmith]

I thought I would have a look fore meters that could read engine RPM.  I'm sure there are better ones out there.

atdtools.com 5585
INNOVA-3340
PDI PDI 895

Harbor Freight has something
https://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html

[Lightages]

I thought I would have a look fore meters that could read engine RPM.  I'm sure there are better ones out there.

atdtools.com 5585
INNOVA-3340
PDI PDI 895

Harbor Freight has something
https://www.harborfreight.com/lcd-automotive-multimeter-with-tachometer-kit-95670.html

I don't know if you want to look at another Brymen, but the BM315 and BM319 are automotive meters.

[joeqsmith]

I downloaded the manual as am a little confused about some of the functions.  Seems like it has the basics covered. 

[joeqsmith]

The HONGDA HD AT2150B, $30.    Manual ranging but has separate current inputs.    Some come with an inductive clamp, others like this one do not.   

[totalnoob]

Since this thread has now branched into automotive specific meters, anyone know of any that can be used with one or two cylinders, instead of the usual 3 - 8?  I have more of a need for a meter that can read RPM's of single or dual cylinder small engines.

Paul

[stj]

wouldnt that just be the frequency function, and multiply the reading by 30 or 60?

[Gregg]

Since this thread has now branched into automotive specific meters, anyone know of any that can be used with one or two cylinders, instead of the usual 3 - 8?  I have more of a need for a meter that can read RPM's of single or dual cylinder small engines.

Paul

Fluke 88 lists an optional inductive pickup that clips around a single spark-plug wire and will measure RPM for a single or multiple cylinder gasoline engine; not good for diesels.
I have an older model Fluke 88 that came with the pickup in a kit form that works very well. 

[exe]

A few people have been asking me about more specialized handheld meters.  One of the most common request I get is for meters with an oscilloscope function.

Are there any "cheap" options? I know only Flukes, they cost a fortune (even old ones).

[joeqsmith]

Since this thread has now branched into automotive specific meters, anyone know of any that can be used with one or two cylinders, instead of the usual 3 - 8?  I have more of a need for a meter that can read RPM's of single or dual cylinder small engines.

Paul

The Brymen seems to.  It's the only manual I have downloaded so far.

wouldnt that just be the frequency function, and multiply the reading by 30 or 60?

The RPM input for many of these meters have an adjustable trigger level.  I would assume they are designed to work with the noise you would normally see.  Math wise it would depend on the configuration.  Any automotive meter I would expect would do the math for RPM as a minimum.

[joeqsmith]

Looking at the Harbor Freight meter, I don't care for the manual range.  Another problem seems to be that they don't handle all the various modes.  So you may need your calculator. 
 

If clamping to any spark plug wire
after the distributor, multiply the
displayed reading by the number of
cylinders x 10 to obtain the RPM value.

If clamping to ignition line I or II, multiply
the display reading by 20 to obtain
the actual RPM value of the engine.

I've never heard of all-sun or e-sun.  They offer a few different ones. 
http://www.all-sun.com/en/p.aspx?px=19

[stj]

these rpm systems are very limited in use btw,
modern cars all use coilpacks, so your meter needs to have a low voltage input for the function.
even a number of pre-coilpack cars used a system of firing a stream of sparks rather than a single discharge, or in the case of alpha-romeo a redundent spark caused by pairing cylinders to a single HT lead.

[exe]

Define "cheap".  A few of the meters I listed were under $50.

Well, under 120euro in EU in a reasonably good condition... Flukes are much more expensive here than in US.

Although, I may not understand what I'm asking, handheld scopes may have isolated inputs which cost a fortune.

[joeqsmith]

Define "cheap".  A few of the meters I listed were under $50.

Well, under 120euro in EU in a reasonably good condition... Flukes are much more expensive here than in US.

Although, I may not understand what I'm asking, handheld scopes may have isolated inputs which cost a fortune.

Any idea what features you want, or is your only criteria that it is cheap?   

I did hear back from Brymen.  Not too surprised as they are always pretty quick to respond.  Their response triggered another question. 

[joeqsmith]

these rpm systems are very limited in use btw,
modern cars all use coilpacks, so your meter needs to have a low voltage input for the function.
even a number of pre-coilpack cars used a system of firing a stream of sparks rather than a single discharge, or in the case of alpha-romeo a redundent spark caused by pairing cylinders to a single HT lead.

The three I have looked at support a low voltage input as well.  Basically, you just don't use the clamp. 

Your comments about the stream of sparks and redundant spark is why the math may not be as simple as you suggest.  Wasted spark is fairly common and I would expect a decent meter would handle it for both 2 and 4 strokes.  If you watch my videos, you may be aware I run an MSD ignition that will put out a variable number of pulses per cycle based on the crank speed.  The meter would need something akin to a blanking circuit to handle this.   This is one of my questions to Brymen. 

[exe]

Any idea what features you want, or is your only criteria that it is cheap?   

Sorry, there was misunderstanding from my side. I wanted to know more about "scopemeters". I thought it's a DMM and oscilloscope in one unit. But it looks like it's just a portable oscilloscope, not so much a multimeter. So, I guess, any handheld oscilloscope can be called a "scopemeter".

[kalel]

Any idea what features you want, or is your only criteria that it is cheap?   

Sorry, there was misunderstanding from my side. I wanted to know more about "scopemeters". I thought it's a DMM and oscilloscope in one unit. But it looks like it's just a portable oscilloscope, not so much a multimeter. So, I guess, any handheld oscilloscope can be called a "scopemeter".

There's this:

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