Testing Resistance - Who to Trust?

[Paratech]

Not too long ago I decided to start building coils.
I've been paying close attention and been doing my research.
Not doing anything complicated yet.
Verified all connections are solid and nothing not where it shouldn't be.
(coil not touching sidewall or anything)
Everything has been going ok and I had no complaints.
But my OCD has drove me to constant testing of everything.
For many things in life I live by "Trust but Verify"
Just because a coil is marked at a certain resistance doesn't mean it is that resistance.
Not only is there a tolerance by manufacture, there is also plenty of room for human error.
(QC in many places spend more time on break vaping then they do working, haha)

During all this I had been noticing a variation in the resistances that I expected to see.
So I grabbed the CM 521 off the corner of the desk and started triple checking everything that had already been checked.
One particular build was just fighting me the entire way.
So I suspected that there was something not right and decided to rebuild that one later and didn't include it in this data collect.
I randomly grabbed some tanks, coils, and mods off the shelf and started testing.
As I am entering the data in the logs I realized I had a much bigger problem at hand than I originally suspected.

My question (after all that shit above) is simple.
What product am I expected to believe/trust?
The mod?
That is proving to be very inaccurate.
The CM 521 tab?
So far I haven't attempted to calibrate it so I don't know if that is right either.
Tomorrow my plan is to go out in the garage and grab my good multimeter and recheck the checks of my checks.
When I can get a different reading from almost every device for the same tank/coil, I find that to be an actual problem.
This was simply testing the resistance of pre-built coils.

 

[martnargh]

trust math. get a resistance calxulator app and follow the schimatics, they wont fail you.
i use a xheap ass sigelei reader and its always pretty close to what it should be mathmatically.

Sent from my SM-N920T using Tapatalk

 

[nightshard]

The way I see it is that as long as you don't push your regulated mod/mech to the limit you are practically safe.
As long as a mod gives a consistent reading even if it's off by a bit and as a result gives a consistent vaping experience there's no point beating yourself over it.

 

[Paratech]

trust math. get a resistance calxulator app and follow the schimatics, they wont fail you.
i use a xheap ass sigelei reader and its always pretty close to what it should be mathematically.

Trusting math will work somewhat fairly close for building coils.
Doesn't do anything for the readings I get on premade coils as all of these are.
Granted, making coils is what caused me to test this.

The way I see it is that as long as you don't push your regulated mod/mech to the limit you are practically safe.
As long as a mod gives a consistent reading even if it's off by a bit and as a result gives a consistent vaping experience there's no point beating yourself over it.

I'm not concerned about the danger portion here because everything falls within a safe range.
My point is simply that I get different readings from the same tank/coil on multiple mods.
What I get from this is not many of them are reading resistance the same way.
With resistance being not only a key component for any TC mod, but also a variable that should be the easiest to grab.
If I take any tank with a coil in it and put it on 20 mods, I SHOULD be able to expect at least the same resistance reading.
Yes, I'll get different results on many other factors but resistance isn't one that should be different.
At least not in my un-professionally trained opinion.

--EDIT--
I want to edit the fact that I AM concerned about the safety, it just isn't what I am trying to measure in this particular test.

 

[HondaDavidson]

Well unless you have a professional level Volt ohm meter I would trust NONE of the readings......Even then is common for reading to vary meter to meter. I generally test builds with at least 2 meters My cheap VOM or My 510 reader or a mod, then average the readings. On BUT the main thing I do is never build anywhere near the amp limit of my batteries or the lower ohm limits of my Regulated mod.

 

[Paratech]

I want to thank all three of you for your replies.
They are definitely not the replies I anticipated.
However they lead me to believe this is not uncommon.
I honestly expected someone to imply this was a total shock and they do not experience the same outcome.
Since none of you implied such a thing you must not be surprised by my results.
That being said, I'll just continue from here and as suggested just use an average of my findings including adding the results of the multimeter.
That may not be required but it'll sooth my inner craziness.
Thanks.

ps, still surprised that this may common and acceptable with the level of hardware we are into now days with all of their other capabilities. I'll get through it IF I can curb my OCD and need for perfection.
We can TC kanthal but not create a trusted and reliable accurate resistance tester.

 

[HondaDavidson]

Yeah.... not to mention that ALL metal has some resistance...... this means that even 2 identical coils on 2 of the same atomizer can and will meter differently . also they may even read differently at different times due to temperature. Even the tightness of the connections can cause slight variances. Then there's the batteries.. some meters vary to themselves due to the charge state of their own batteries.

That's why I have personal safety limits... stricter than those of my devices or batteries. Little mistake just taste bad..... they don't cause smoke to leak from my mods.

Sent from my SCH-I605 using Tapatalk

 

[martnargh]

well... according to math and reality, each wrap over a 3mm bit of 21 gauge nichrome90 should create .02 of resistance.
so, 8 wraps gives ya .16. dual it up and its .08...
my cheapo sigelei reads .08.
the only regulated device i own, a dna200 also reads .08..
this leads me to believe theyre not completely inaccurate.
either way i only check my attys for possible shorts and outer wall clearance... the resistancr is pretty much always where it needs to be.
my builds are never that crazy anyway that its given to chance, fused claptons are as crazy as it gets around here.

Sent from my SM-N920T using Tapatalk

 

[captgreg]

Glad I'm not the only one that checks with at least 3 different devices when I build my coils I try and stay in the high .40's to low .50's anything lower and I'm afraid I may be headless.
See your not crazy we all are.

 

[TheRealSean]

I want to thank all three of you for your replies.
They are definitely not the replies I anticipated.
However they lead me to believe this is not uncommon.
I honestly expected someone to imply this was a total shock and they do not experience the same outcome.
Since none of you implied such a thing you must not be surprised by my results.
That being said, I'll just continue from here and as suggested just use an average of my findings including adding the results of the multimeter.
That may not be required but it'll sooth my inner craziness.
Thanks.

ps, still surprised that this may common and acceptable with the level of hardware we are into now days with all of their other capabilities. I'll get through it IF I can curb my OCD and need for perfection.
We can TC kanthal but not create a trusted and reliable accurate resistance tester.

Man you are detailed I have alittle ocd but add is my problem. Did a test myself using vt75, 213 and multimeter. Dont have any rta ready for a build but used amigo driptide tank. (Freebie never been used) Coil reads .5 screwed in mods and build meter. With tank complete and just coil in base. Then measured resistance with multimeter everyway I could think of. Took reading with coil in tank base, in my build meter, in mods using outer screw as ground, have wood block with 510 in top do builds on got reading off that, read resistance off coil itself, even pulled plug out bottom of coil measured across the wire itself. I know didnt use exactly what you used.It was .5 one the money on everything except the Vt75. Most expensive thing I measured on was off read .55 not much but off. So to have another reading that I would trust is a multimeter.

 

[Train]

Your readings just aren't that far off - you've got a variance of what, typically two HUNDREDTHS of an ohm...
I think you're fine. Just know that the Smok runs a little high, and maybe "settle" on the 521 as your standard, so you can recreate something accurately...

 

[Paratech]

Man you are detailed I have alittle ocd but add is my problem. Did a test myself using vt75, 213 and multimeter. Dont have any rta ready for a build but used amigo driptide tank. (Freebie never been used) Coil reads .5 screwed in mods and build meter. With tank complete and just coil in base. Then measured resistance with multimeter everyway I could think of. Took reading with coil in tank base, in my build meter, in mods using outer screw as ground, have wood block with 510 in top do builds on got reading off that, read resistance off coil itself, even pulled plug out bottom of coil measured across the wire itself. I know didnt use exactly what you used.It was .5 one the money on everything except the Vt75. Most expensive thing I measured on was off read .55 not much but off. So to have another reading that I would trust is a multimeter.

Yeah my OCD (CDO for those that require it be in alphabetical order) does indeed take me down the longer path most generally.
However that has also helped me live by the "Trust but verify" motto that I embrace.

Your readings just aren't that far off - you've got a variance of what, typically two HUNDREDTHS of an ohm...
I think you're fine. Just know that the Smok runs a little high, and maybe "settle" on the 521 as your standard, so you can recreate something accurately...

Thanks for posting this.
It reminded me to return to state exactly what you just said.
After further testing I came to the conclusion that most generally each device continues to read the same coil/build at the same reading each time.
With that proven it lead me to decide that even though my OCD says it MUST be correct, I'll continue to breath even if I decide that picking one particular device (521 tab) and just trusting that it is correct, will probably be the best choice.
From this point I'll NOT retest against other devices because that will just cause me to have to do this entire test all over again.
Where if I simply verify my 521 tab against my multimeter once in a while, all will be well.