Poll

Are you interested in seeing more handheld meters tested?

This testing is pointless! Please STOP damaging these meters!
3 (6.7%)
 Yes, I would like to more meters tested.
42 (93.3%)

Total Members Voted: 45

Author Topic: Handheld meter electrical robustness testing.  (Read 493701 times)

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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2900 on: October 19, 2018, 08:44:14 am »
"... a company or a product that is not listed is not necessarily untested and does not necessarily fail to meet the regulation (UL/EN/CSA 61010 in this case).

Unless I'm misunderstanding you, I don't agree - ma and pa can't test compliance to a safety standard in their garage, write up a report and say it's all good. Too much chance of corruption and mistakes.
That is fine. It is your opinion. It doesn't mean it is enforceable/applicable/true for all scenarios/countries/etc.

OSHA list of NRTL's: (...)
Yes, that is correct. We have established that US/Can is different than worldwide. What OSHA says is restricted to US.

Look, I have no horse in this race. I don't really care if Sanwa or Hioki or Uni-T or Aneng have tested their stuff or not - I am an enthusiast that happens to be involved professionally with this whole compliance deal (not test equipment). My attempt with this discussion is to clarify that the marketing product offered by certification agencies to promote compliance ("UL listed", "ETL", "TÜV Rheinland" markings) is not the only way to demonstrate a product's compliance and should not be a pre condition to dismiss a product in this area.

I think we sprinkled this thread with enough boring compliance stuff. I will refrain from replying on this subject. Peace.
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2901 on: October 19, 2018, 08:47:25 am »
Slide 18 for the suggestion of a test...  :-DD

Slides 21 ~ 23 as good references when you are analyzing or making modifications on a DMM.

Anyhow, I just thought it was nice how they presented the information. Quite clear in my opinion.

It looks like this person updated their presentation in 2010.  Do a search for their name or that UL flame test.   They added a few pages.

I think I have melted a meter with a soldering iron before but I've never torched one.  I keep the Halon handy if that time ever presents itself.   :-DD
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2902 on: October 19, 2018, 08:48:15 am »
I have a question about a clamp meter Unit 204A that has intertek / ETL logo and a S.N. Number :P

http://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/?action=dlattach;attach=503906

From here it looks good but check this on the manual (see attachment) On the temperature sensor 1K resistor in series. You plug the meter into 230V in this mode and its bye bye...

So they may ommit some functions during the certification?

I wish I had access to a recent copy of the standard. That would better clarify this scenario.

AFAIK the CAT testing does not guarantee the survivability of the meter - only the survivability of the operator.

That is the sole reason why Joe's tests are so interesting - they give an idea of robustness but are too weak to test survivability (maximum he can get is a *poof* and not a *BOOOOOM*) :)
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2903 on: October 19, 2018, 09:14:51 am »
If I were experimenting at home with levels that could make a BOOOOM,  I may actually have some interest in safety.  Then again, my lab and power distribution would be much more interesting than it is!   :-DD
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2904 on: October 19, 2018, 09:19:48 am »
Looks like True stopped posting.
001 as well.  ;D

Joe, one interesting meter that you may consider testing in the future is the nice PM300 from Sanwa; it is rated for CATIV 300V / CAT III 600V and is quite well built. It is protected by a GDT and a Varistor on a string of resistors.


Think the SANWA would survive to higher levels than this little Brymen?  Did Dave do anything to it electrically in his reviews?   
Just a hunch but I suspect so, given that Sanwa is a very reputable japanese brand that would not lie about CAT ratings.

Dave did not put it through its paces, though.

Take your best guess where you feel the Brymen will fail.   I will consider a breakdown in an unintended area a failure.  It fits in a shirt pocket so things are pretty tight in there.   2KV?    What about the SANWA you mention?   Think it's double?  4KV? 

Based on what True posted, it may not even make it that far in the testing!   :-DD
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #2905 on: October 19, 2018, 10:37:57 am »
Working with 230V isolated from mains, 6VA currently and it can put in a lot of trouble if safety is discarted. At least is documented on the meter's manual.


Guess for Brymen... pocket meters... disposable ... personal ut120c freezed when battery got low....  maybe with issue ESD wil take it out .

 
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2906 on: October 19, 2018, 11:00:25 am »
1 vote for ESD
1 vote for > 6KV
   

This will be the sixth Brymen I have looked at in detail.  I've been very impressed with how well they have done.   I'm going to guess that it can survive at least to the levels my low voltage generator can put out.  So more than 6KV. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #2907 on: October 19, 2018, 09:10:39 pm »
Wow there is a discrepancy between odds. It may be the version for the bad or good unit. If it survives 6kv then its a Brymen pocket meter well done. Maybe sanwa has some touch to it...

The setup of isolated 230v does not make boom but it can buzz the transformers or bad connections, eg v shape banana plugs.

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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2908 on: October 19, 2018, 10:18:08 pm »
I purchased a new unit after my PM55A had failed, only to find a PM55 I gave to a friend also failed. I tested a PM55 I had and it too had failed. The replacement? Well, it tested good (testing 5V in auto mode, and shorting probes, that's it...); after a month when I went to use it to test a low voltage DC circuit again, it showed low battery ... and sure enough it failed too.

If True were still around, they may vote that it won't survive a basic functional test.   :-DD 

I've been running some low voltage, non-destructive tests, looking for some test case that would go along with what True posted.  At least four meters with the same failure mode, I should be able to replicate it.   Then again, maybe True was Trolling and there's no Truth in what was posted?   Hard to say but you can be assured that I will do my best to send this meter to the recycle bin.
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #2909 on: October 19, 2018, 11:11:29 pm »
With that test we can see the meter in action. Trash bin? Pocket meters really after seeing my ut120c hang the lcd on low bat i believe that can happen if similar chipsets are being used.
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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2910 on: October 20, 2018, 02:30:24 am »
I re-watched Dave's shootout and saw how electrically well built the Brymen was - although mechanically flawed. The Amprobes also took a beating, therefore my guess is that the little PM55A will fail at a higher level than the ESD gun. I would guess ≥6kV.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2911 on: October 20, 2018, 05:55:32 am »
So that's 

1 vote for won't make it past the functional test  :-DD taking liberty with True's posts until they return.   :-DD
1 vote for ESD
2 vote for > 6KV

If you feel the SANWA can survive to even higher levels than the Brymen, are you thinking it's in Fluke 101/107 territory? 

What do you feel is a mechanical flaw with the Brymen?   There is something I really don't like about the mechanics but I doubt it's the same problem.   Because often I run these meters to failure and I try to analyze why they fail, I want to be able to run the PCB open case.  The way the LCD, switch and battery are mounted to the case, it would make it difficult to work on.   I'm sure we will find out just how difficult. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline tautech

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Re: Handheld meter electrical robustness testing.
« Reply #2912 on: October 20, 2018, 05:57:08 am »
Joe, something you might want to look into with the bigger Brymens and maybe other meters too:


Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.

Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up.  :-\
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2913 on: October 20, 2018, 06:52:01 am »
Joe, something you might want to look into with the bigger Brymens and maybe other meters too:


Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.

Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up.  :-\

What's this about?   I do normally sweep them to see if there are areas they are sensitive at.  Post a link or details about exactly what they are doing, their test setup, modulation....

I played around with a few of my meters once I picked up that Gossen at 10V/m, swept to a GHz. 
https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840

I still have my old Vibroplex
https://youtu.be/QBho9XD7VPQ?t=79
« Last Edit: October 20, 2018, 07:01:11 am by joeqsmith »
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Offline tautech

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Re: Handheld meter electrical robustness testing.
« Reply #2914 on: October 20, 2018, 06:58:53 am »
Joe, something you might want to look into with the bigger Brymens and maybe other meters too:


Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.

Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up.  :-\

What's this about?   I do normally sweep them to see if there are areas they are sensitive at.  Post a link or details about exactly what they are doing, their test setup, modulation....

I played around with a few of my meters once I picked up that Gossen at 10V/m, swept to a GHz. 
https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840
I know and watched all you did with the Gossen to get it immune to the near field and magnetiser sensitivity.
You can glean a little more about the circumstances here:
http://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1898834/#msg1898834
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2915 on: October 20, 2018, 07:15:17 am »
Hummm.  I have no idea what they are doing.  You don't think they stuck the meter between the output and the load at 7MHz do you?   :-DD  I am guessing they are looking at the DC supply side but I can't find where they show a lot of details.  Maybe they will write something up and post some pictures. 

I'm sure I could come up with 7MHz at 25W. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2916 on: October 20, 2018, 07:26:19 am »
If you feel the SANWA can survive to even higher levels than the Brymen, are you thinking it's in Fluke 101/107 territory? 
I really don't know. I suspect both would be equivalent (I hope I don't eat my hat if you happen to test the PM300 in the future).

What do you feel is a mechanical flaw with the Brymen?   There is something I really don't like about the mechanics but I doubt it's the same problem.   Because often I run these meters to failure and I try to analyze why they fail, I want to be able to run the PCB open case.  The way the LCD, switch and battery are mounted to the case, it would make it difficult to work on.   I'm sure we will find out just how difficult.
In the original shootout video from Dave, he found out that twisting the Brymen was wreaking all sorts of crap on its screen. But perhaps it was a different model (so many OEMs/rebrands)
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2917 on: October 20, 2018, 07:43:19 am »
Ah, the twist test.   I showed my wife one of Dave's reviews and when he starts to twists the meter she busted out laughing.  It must have made an impression because months later when I told her I was planning to run one of Dave's production meters, the first thing she asked is if I was going to twist test it.    I need to start weight training.   :-DD

It seems very subjective. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 

Offline IanB

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Re: Handheld meter electrical robustness testing.
« Reply #2918 on: October 20, 2018, 08:35:54 am »
Ah, the twist test.

It beats me how people manage to put their phones in the back pocket of their jeans and then sit on them without breaking them.

When people do that with wallets all their credit cards come out bent.
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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2919 on: October 20, 2018, 09:09:58 am »
Take your best guess where you feel the Brymen will fail. 
I forgot about this question. IIRC from your tests, the well built meters tend to have the point of failure around the clamp diodes/transistors. Obviously that may change to the rotary switch due to the sheer space constraints.
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Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2920 on: October 20, 2018, 09:31:04 am »
You have learned well.  :-DD   I have yet to damage a MOV with all the testing I have done.  I don't think I have ever damaged a surge rated resistor.   It's almost without failure the high high speed clamps that fail in the higher class meters.   Diodes, transistors, etc.  In the cheap meters, the piss ant  PTCs will commonly fail.  That's if the meter even has them.  Mostly its the main IC that does them in.

Dave's little UEI meter is a bit of an odd ball with that 15V diode check seeming to be the weak point when I looked at it.  A couple of KV will take the MUX first.  The UNI-T UT181A is just a bad layout which is really too bad.

Then we have that UNI-T UT90A.  That meter has more lives than a cat.  There's not enough clearances to things just break down and save the meter.   I have done everything I could to finish that meter off shy of building a higher powered generator.   

This little Brymen has the basics.  PTC, spark gaps, clamps, lots of slots in the PCB.  Yet True damaged four of them.   Something is very strange.. 
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline joeqsmith

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Re: Handheld meter electrical robustness testing.
« Reply #2921 on: October 20, 2018, 01:22:43 pm »
Joe, something you might want to look into with the bigger Brymens and maybe other meters too:


Also found another issue with the BM867s. If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down. Fluke, fine. Keysight, fine. Hmm. This is why I haven’t dropped my review yet. I still like it but not for that.

Not sure what you've got to replicate RF keying or if you even want to give yourself a slight RF fry up.  :-\

What's this about?   I do normally sweep them to see if there are areas they are sensitive at.  Post a link or details about exactly what they are doing, their test setup, modulation.... 

I played around with a few of my meters once I picked up that Gossen at 10V/m, swept to a GHz. 
https://youtu.be/wYuzFtoHMqg?list=PLZSS2ajxhiQBTCU8Mq_i9jidT024A0dV6&t=840
I know and watched all you did with the Gossen to get it immune to the near field and magnetiser sensitivity.
You can glean a little more about the circumstances here:
http://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg1898834/#msg1898834

First, I don't recommend anyone ever try this at home with a meter they value.  Obviously, I have no way of knowing what they were doing. So let me try and set up a VERY bad and stupid thing to do.    :-DD

The Brymen BM869s was set to Amps and the signal generator set to 7MHz.   The meter placed DIRECTLY IN SERIES with a 50 ohm load.  The load has a tap going back to the DSO to monitor power.

The DSO is showing 746mV which is well over 100 Watts. Yes the load was HOT in short time.  :-DD

Of course I am not expecting the Brymen to throw up any useful data.   "If it’s sitting in series with the PA monitoring current it goes bloody mental when you key down."  What bloody mental means is anyone's guess.   The meter didn't reset,  show random data, power down and it didn't smoke. 

Maybe this is what damaged True's meters!
« Last Edit: October 20, 2018, 01:24:53 pm by joeqsmith »
How electrically robust is your meter?? http://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline malagas_on_fire

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Re: Handheld meter electrical robustness testing.
« Reply #2922 on: October 20, 2018, 10:53:36 pm »
It is useful when people  mention issues with meters and at least give the test conditions.
The uni-t 90A is the one have "fusible" tracks ?

About the Little Brymen, even it has the components and layout, does it have enought to withstand a ESD event?

The Amprobe functional test either it could be related to a batch issue, improper use of the meter, so you could get one good batch, do a proper use of the meter and get a different result from the test.


[Edit]

The Brymen in case is the BM27s and it is similar to the Ambrobe PM55A, but the supplied leads are different, and brymen has protective caps on the leads. Doesn't change the test but changes the aspect in terms of trying to do it more safe to hands... yeah...



« Last Edit: October 20, 2018, 11:17:21 pm by malagas_on_fire »
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Online Housedad

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Re: Handheld meter electrical robustness testing.
« Reply #2923 on: October 20, 2018, 11:11:10 pm »
Ah, the twist test.

It beats me how people manage to put their phones in the back pocket of their jeans and then sit on them without breaking them.

When people do that with wallets all their credit cards come out bent.

Oh they do get bent. and cracked. and twisted. and dropped.  Don't let anyone fool you.

I have two daughters now in their early 20's. Add in my wife, and my sister.   I hate thinking about how many tablet,  Samsung phones and Iphone backs and screens I've replaced over the years or had to reform the corners and backs.  Off the top of my head, I think I have about 5 back straightener dies and the same # of corner straighteners in my 'phone box' of tools.  They can be rough on them sometimes.  I got tired of fixing them and their tablets all the time and told them to just pay for the insurance plan when they hit 20 years old.  They end up replacing them at least once a year on the plans.  Freedom is bliss.

The worse ones of all was the early Apple tablet about 6-7 years ago.  Seems that the ribbon cable connector on the main board to the screen would come off if you just looked at it.  I did not have hot air tools for reflow back then so I had to farm it out when it happened.  PITA.
« Last Edit: October 20, 2018, 11:17:22 pm by Housedad »
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Offline rsjsouza

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Re: Handheld meter electrical robustness testing.
« Reply #2924 on: October 21, 2018, 01:05:28 am »
I was going to mention that as well. Cracked screens is a very common thing. When Apple released their slender phone (iPhone 6S, IIRC) the overall reaction was very negative with the bent phones. That's when people realized the blatantly obvious fact that putting a phone on the back pocket and sitting on it was actually a bad idea.

Fortunately for me, my wife is careful with her phone - although her last phone had a cracked screen, it only happened after many years of use and quite understandable as handling three year old twins is not an easy thing to do - an accident was bound to happen.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 


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