Meaning of multimeter readings for ohms

[glassmanoak]

I know how to use a multimeter correctly. I just want to know how to interpret the results if I know the begining resistance of an atty. For example, I started with a 4.0 ohm atty. After some time, it now reads 4.7 ohms. What does this mean? What does it mean if the resistance is 3.5 ohms? None of the youtube videos tell the interpretation, just how to use the meter.
Thanks

 

[bruiser]

If the ohms increase, that means the resistance is increasing, and vice-versa.

 

[Stosh]

When the resistance starts changing, it usually means the atty or carto is nearing the end of it's life.
The performance will change a bit, more or less vapor and heat. Make sure to have spares!!

Also always put the meter leads together to see what the resistance of the leads are, usually a
couple tenths of an ohm, and subtract this from your reading on the atty.

 

[Hoosier]

After subtracting the lead resistance as Stosh refers to, you can encounter the effect of parallel resistance when juice is touching the coil and there is also the effect of oxidation and/or heat to the resistance of the coil. Expecting resistance to be a completely static and/or exact value is from a perfect world which I've never lived in.

There are many aspects with DC electronics that are generally ignored to keep the equations clean and ignore the spurious effects that don't really effect the final result when all is said is done. Resistors are graded in terms of the degree of variances they could be from the stated value. Atomizer and cartomizer coils are not graded in these terms usually, so if your results are in the 10% from the stated value, you are doing great. I don't fret 20% variance myself.

 

[Katya]

And, in more basic terms, knowing the resistance of your atomizer is critical to finding your sweet vaping spot, so to speak.

What really matters is the amount of heat (power) generated by your battery and your atomizer working together. Are you familiar with the Ohm's law?

Wattage (heat, power) equals Voltage squared divided by resistance. The recommened safe and satisfying range is usually ~4.5-8 Watts. At that Wattage, the eliquid gets properly vaporized, the battery life is not sacrificed, and the warmth of the vapor produced, and the flavor of most ejuices, seem to be ideal--and, of course, the risks of burning the filler or juice or popping an atomizer coil are kept to a minimum.

Example 1: A 2.5Ω atty on a 3.7v battery will generate 5.5 Watts and offer a quite satisfying vaping experience, suitable for most flavors.

Example 2: The same 2.5Ω carto on 6v will give you 14 Watts, which is sheer madness (IMHO)! The battery life will be cut in half and the heat (power) generated by this setup will fry any carto filler and possibly pop the coil of many atomizers in no time flat! It will also burn the juice and alter its flavor.

There is a happy place for every vaper. Experiment and see what Wattage works for you. Start low and work your way up until you're satisfied. Remember also that too much Wattage will alter the taste of your eliquids or even burn them. Generally, tobacco flavors can take a little more heat, while fruit and some dessert flavors do better at cooler temperatures.

Here's a handy dandy Ohm's Law Calculator. Don't leave home without it.

Online Conversion - Ohm's Law Calculator

Good luck and happy vaping!

 

[Kent C]

I just want to know how to interpret the results

http://www.e-cigarette-forum.com/forum/joye-510/33880-510-atty-lifespan-5.html#post648329 post#47

Note that while Scott talks about the build up - it is the oxidation of the nichrome (as Hoosier points out) that is where the higher resistance is coming from. Lower resistance - a "2.2Ω atty" showing 1.0Ω on the meter is a 'semi-short' where something is near shorting the coil.

http://www.e-cigarette-forum.com/forum/tips-tricks/40061-atty-resistance-increasing.html#post605488 post#6 and subsequent posts in that thread give you some info....

Note also that while the gunk doesn't 'increase resistance' itself, it can cause an increase in resistance by deading parts of the coil and straining other parts of the coil, so cleaning (imo, with PGA - I use high proof vodka) - while it isn't going to 'bring back' an atty, it will save an atty from getting to that condition.

 

[Katya]

On the other hand,

http://www.e-cigarette-forum.com/fo...r-attys-kill-ego-batteries-4.html#post2357220

http://www.e-cigarette-forum.com/fo...d-old-sticky-threads-1-a-128.html#post1205584

To put it simply, the resistance of your atty should stay within 10-20% of the stated value, as Hoosier said. If it's more than that, you should be aware that there are three things that can go wrong with atty wiring: “opens” (broken wires), partial opens or shorts.

If your atty reads a very high resistance (K Ohms, M Ohms, or infinite Ohms) then it is "open," which means it's dead. If it reads much higher than it should, it usually indicates a partial break somewhere, which means it's on its way to die.

0 Ohms reading means a direct short. Your atty is just as dead.