ProVari consistantly says coils are .4 ohms lower than ohm tester...which one is right?

[desertrider]

So, Ive had my ProVari for about 2 weeks now, and have built 3 or 4 coils for it. In every case, the Provari read the coil .4 ohms lower than my ohm tester. I mean, its not the big of deal now that I know, but its just interesting to me.

Im tending to think the ProVari is correct. I trust that device over a chinese made ohm tester lol. So what I do now is, if I want a 1.6ohm coil, I make sure it tests at 2.0 on the tester.

Thoughts?

 

[stevegmu]

I would trust the ProVari. My guess is if you tested the coil with a quality multimeter, like a Fluke, you would get the same results as that of the ProVari. ProVape is all about safety; my guess is their ohm meter is as accurate as a Fluke...

 

[desertrider]

I would trust the ProVari. My guess is if you tested the coil with a quality multimeter, like a Fluke, you would get the same results as that of the ProVari. ProVape is all about safety; my guess is their ohm meter is as accurate as a Fluke...

Thats my gut instinct as well. Ive seen the video about Provape with phil, and theyre all about safety and accuracy. Thanks for the confirmation.

 

[Jugband]

Just a thought, are you checking the resistance of your DMM and subtracting it from your build?

 

[desertrider]

checking the resistance of what? Im not familiar with what DMM is

 

[Jugband]

Sorry, DMM Digital multimeter. Before you check the resistance of your build are you checking the internal resistance of your multimeter? You take your leads and hold them firmly together, the number you see is the restiance of your meter. Now check your build, subtract the number you just saw. For example, if your multimeter read .4 and your build read 1.4 your true build ohms is 1
Just kinda sounded to me like that would explain your problem.

 

[GeorgeWachsmuth]

It sounds like he's using a "Chinese made ohm tester" not a meter. Desertrider, you might want to get another ohm tester......

 

[Jugband]

It sounds like he's using a "Chinese made ohm tester" not a meter. Desertrider, you might want to get another ohm tester......

I wondered that also. Wasn't sure? Thought I'd take a shot. In any case, I agree if your using a "Chinese made ohm tester" you would do well to purchase a decent multimeter. You can pick one up cheap, really a vapers must!

 

[tobarger]

Your meter is reading the resistance of the coil plus the meter and test lead resistance which is about .4 ohm
I have a few good meters and they all read about .4 ohm over the actual resistance
Some meters have a "Relative" function which will cancel out the meter and test lead resistance

My Provaris on the other hand give very accurate resistance measurements

 

[desertrider]

Learn something new every day. Now that youve explained the DMM resistance it rings a bell that Ive read it before. Ill check it out.

Thanks again guys-

 

[plop1]

Hi all, I'm starting to have doubts regarding the Provari ohm reading accuracy: I have 3 mini Provari at the moment. All 3 give a different result when testing the same Boge carto, using the same battery.
2.8 ohms, 2.9 ohms, and 3.0 ohms.
Two days ago I had the exact same results with another carto. Can't tell which one is right.

However when I did the test on an aerotank mega (stock coil), 2 of them agreed on 2.2ohm while one insisted on giving a lower result (2.1 ohm).

 

[tobarger]

Hi all, I'm starting to have doubts regarding the Provari ohm reading accuracy: I have 3 mini Provari at the moment. All 3 give a different result when testing the same Boge carto, using the same battery.
2.8 ohms, 2.9 ohms, and 3.0 ohms.

1) Three Provaris - The difference between the highest and lowest readings is 0.2 ohm

However when I did the test on an aerotank mega (stock coil), 2 of them agreed on 2.2ohm while one insisted on giving a lower result (2.1 ohm).

2) Three Provaris - Two give the same resistance reading and the other one gives a reading 0.1 ohm lower
....The difference between the highest and lowest readings is 0.1 ohm

Seems to me like there is nothing wrong with the Provaris
There is a percentage of tolerance for anything electronic
And even each component of any electronic device has a percent tolerance
Perfect is very rare

 

[Maurice Pudlo]

The question here would be are each of the three Provari reading consistent as in every time you install and reinstall the same carto does that Provari read the same each time?

If so, the difference you see is the difference in each unique Provari build in terms of it's internal resistance.

I'm not sure Provari is able to calibrate their devices to zero out 0.2 ohms or not, but you might ask them. Otherwise the provari isn't intended to fire anything unsafe so an error of +/-0.2 ohms on a 1.2+ ohm coil is hardly problematic.

For safety sake I like to assume an error factor of 10%, meter reads 1 ohm assume its 0.9 ohm, meter reads 0.5 ohm assume its .45 ohm and so on. Battery says its a 30 amp continuous assume its really 27 etc. For the most part that'll give you some head room.

Mind you 10% is not going to help you much if the advertised battery stats are way inflated in the first place, but that's another story in and of itself.

Maurice

 

[plop1]

Oops I didn't even know there was such a thing as internal resistance... Thanks for your post