New to the forums, AGA resistance question.

[Niko49]

Hey guys, I'm new the forums and been vaping for about 2 months. I recently got into rba's and picked up an AGA-T+ and love it! I did have a question regarding resistance, but couldnt post in the "Atomizer Issues" section; Guess I'm too new.

Anyways, I got my AGA-T+ setup with some 400 ss mesh and a 4/5 wrap of 32 AWG Kanthal A-1. When I first built the coil I checked the resistance without a wick and got 1.8ohms. I then dry fired the coil a few times without a wick and checked again, and was still at 1.8ohms. I then oxidized my wick and poped it in. After I got the wick in place I checked the resistance again and was still at 1.8ohms. I then proceeded to vape for about half a day and then checked my resistance, this time I was at 2.0 ohms. It still tasted fine and was producing good vapor/throat hit so I didnt really care, I proceded to check the resistance through out the day and it would vary between 1.9 ~ 2.0ohms.

My question is why is my resistance fluctuating, and is this normal? I have been testing the resistance with my Vamo V2, and verified its accuracy with my expensive multimeter. I've been vaping between 8 ~ 10 watts.

 

[Baditude]

Hi, Niko. Although I'm a more experienced vapor and have been using cartotanks exclusively for several months, I just started using a couple of AGA T2's myself for about a month now.

I have been noticing changes in the resistance of my coils, too. I'm also perplexed by this and can not explain what this is due to.

Some things to check would be to insure that the positive and negative screws are tight for each end of the coil. Twisting the wick within the coil can make minor adjustment of the coil resistance, as well as nudging the wick either tighter or looser on the positive end of the coil. Other than that, perhaps those that are more experienced can add their input.

 

[Niko49]

Thanks for the response, I guess it might be normal.


Also, anyone else's AGA-T+ appear to be "bent"? If I look at the AGA-T+ fully assembled and the wick hole pointing south, I can tell that the unit bends south west a little. I know this is a stupid question, but I'm a perfectionist and it drives me up the wall, I'm not sure if its the tank or the seals that is causing it, but I plan to investigate further when I get my glass tank.

 

[Kanj.nguyen]

Does it look bent while mounted on a VAMO?

Mine does, and i think its an optical illusion.

 

[Baditude]

Thanks for the response, I guess it might be normal.


Also, anyone else's AGA-T+ appear to be "bent"? If I look at the AGA-T+ fully assembled and the wick hole pointing south, I can tell that the unit bends south west a little. I know this is a stupid question, but I'm a perfectionist and it drives me up the wall, I'm not sure if its the tank or the seals that is causing it, but I plan to investigate further when I get my glass tank.

I've not noticed what you describe in my two AGA's. Are you sure you assembled it correctly?

 

[NancyR]

Alot of times the resistance will change slightly due to gunk building up on the coil not always where you can see it. What I do, is dry burn between every tank and have an old toothbrush I keep handy to help remove the gunk.

I have also noticed juices with more flavoring, coloring or really sweet will gunk up faster.

 

[Kanj.nguyen]

I actually try to maintain a nice layer of gunk. It makes for better heat contact.

 

[Niko49]

Does it look bent while mounted on a VAMO?

Mine does, and i think its an optical illusion.

Yes, but I can also tell its bent when its not mounted on anything. I also though it was an optical illusion but I can follow the bend as I turn the unit.

I've not noticed what you describe in my two AGA's. Are you sure you assembled it correctly?

Pretty sure, it doesnt leak or anything. My guess is that one of the seals or tank isnt completely level.

 

[miketreeguy]

Thanks for the response, I guess it might be normal.


Also, anyone else's AGA-T+ appear to be "bent"? If I look at the AGA-T+ fully assembled and the wick hole pointing south, I can tell that the unit bends south west a little. I know this is a stupid question, but I'm a perfectionist and it drives me up the wall, I'm not sure if its the tank or the seals that is causing it, but I plan to investigate further when I get my glass tank.

Mine is also bent. It came that way from the vendor and it appears to have worsened. I must have put pressure on it or something.

 

[eHuman]

Recheck your positive and negative connections. Higher resistance points to a loose coil connection, lower resistance points to a short.
My coil Ωs do not creep even after a couple of weeks.

 

[SoundlessHero]

Resistance wire is calculated by R = ([Ro] L)/A , [Ro] = resistivity, L = Length and A = cross sectional area

An applied electric field superimposes a small drift velocity on the free electrons in a metal, in which case ours are made to be resistive on those free electrons. In otherwords: Because we're using a small L of wire, it's common to have fluctuations of small amounts with respect to the Fermi speed of the free electron in resistive material. Res wire is also anti-oxidization, so I would make sure you heat treat it uniformly before building your coil.

 

[Chakthi]

Hey guys, I'm new the forums and been vaping for about 2 months. I recently got into RBA's and picked up an AGA-T+ and love it! I did have a question regarding resistance, but couldnt post in the "Atomizer Issues" section; Guess I'm too new.

Anyways, I got my AGA-T+ setup with some 400 ss mesh and a 4/5 wrap of 32 AWG Kanthal A-1. When I first built the coil I checked the resistance without a wick and got 1.8ohms. I then dry fired the coil a few times without a wick and checked again, and was still at 1.8ohms. I then oxidized my wick and poped it in. After I got the wick in place I checked the resistance again and was still at 1.8ohms. I then proceeded to vape for about half a day and then checked my resistance, this time I was at 2.0 ohms. It still tasted fine and was producing good vapor/throat hit so I didnt really care, I proceded to check the resistance through out the day and it would vary between 1.9 ~ 2.0ohms.

My question is why is my resistance fluctuating, and is this normal? I have been testing the resistance with my Vamo V2, and verified its accuracy with my expensive multimeter. I've been vaping between 8 ~ 10 watts.

Hey Niko. Same thing here. Just got my AGA-T+ 2 days ago, but am getting the hang of building the coil. The one I'm using now started out at 1.8 ohms, and stayed within .2 ohms for the 1st half of the tank. However, it jumped massively to 3.8 ohms, and now is slowly dropping down. At present, it reads 2.3 ohms. I took the top cap off, and fired it a few times, and checked the ohms in between. It looks to me as if it might be caused by liquid that gets stuck between the bottom of the coil and the base. While I was watching, it popped louder than the usual sizzle, and a liquid droplet under the coil broke up, and when I checked the resistance, it had dropped massively. It seems to me though that it shouldn't be affected by the liquid that way. Anyone have any insight into this?

 

[Chakthi]

Check your negative screw Niko. I just soaked up all the liquid and it jumped to 4.3 ohms on me, so even though I was certain I tightened the negative screw down tight, I thought I'd check it again to be certain, and to my surprise, it moved just the smallest amount one could imagine, but now my coil is holding steady at roughly 2.0 ohms which is good for me atm. I don't think .1-.2 variance now and then is out of the ordinary, but the jumps I was seeing were definitely not right. lol Thanks to eHuman for the suggestion to check those connections! I think that was the issue.

 

[eHuman]

Resistance wire is calculated by R = ([Ro] L)/A , [Ro] = resistivity, L = Length and A = cross sectional area

An applied electric field superimposes a small drift velocity on the free electrons in a metal, in which case ours are made to be resistive on those free electrons. In otherwords: Because we're using a small L of wire, it's common to have fluctuations of small amounts with respect to the Fermi speed of the free electron in resistive material. Res wire is also anti-oxidization, so I would make sure you heat treat it uniformly before building your coil.

??????????

It is not common to have resistance fluctuations in an RBA unless there is a short or a loose connection. The wire is 1 - 1.5" long, you are talking about a 300% deviation and calling it normal? And yes I have an advance electronics education so I'm not, "just saying".

 

[IntelligentDesigner]

Resistance wire is calculated by R = ([Ro] L)/A , [Ro] = resistivity, L = Length and A = cross sectional area

An applied electric field superimposes a small drift velocity on the free electrons in a metal, in which case ours are made to be resistive on those free electrons. In otherwords: Because we're using a small L of wire, it's common to have fluctuations of small amounts with respect to the Fermi speed of the free electron in resistive material. Res wire is also anti-oxidization, so I would make sure you heat treat it uniformly before building your coil.

Geesh, Dr. Knowitall, acting like a scientist or something. Oh, yeah, you are. I remember the silica dust solution.

Could it also be an accuracy issue within the mod's built in tester?

 

[Chakthi]

LOL - SoundlessHero's answer... I get the idea of what he is saying, but it was just way over my head! I think he was just stating that some fluctuation is normal, though he wasn't addressing any amount in particular. That was what I took from it anyway.

 

[SoundlessHero]

??????????

It is not common to have resistance fluctuations in an RBA unless there is a short or a loose connection. The wire is 1 - 1.5" long, you are talking about a 300% deviation and calling it normal? And yes I have an advance electronics education so I'm not, "just saying".

I'll have to double check the 300% deviation from the OP tom as I'm under the weather at the moment I didn't think that it was that high. I probably didn't read it close enough. I included the equation for future posters as an explanation between resisitivity and resistance.

Resistivity changes by temperature, the calculation is an approximation and resistivity is not length dependent. So depending on the wire, a 300% fluctuation might be acceptable? I don't know, I can run the numbers with Kanthal A1 tommorrow. I do recall that copper could be as much as 0.50 Ohms from 0-100 Celsius - regardless of length. You're probably right, my coils usually stick at 1.7 can change from +/- .2 ohms

Hopefully, I feel better, haven't been able to vape at all the last two days and just got some Johnson Creek juice in, too. Double sad faces

 

[Kanj.nguyen]

I dont think coils should deviate so much in resistance from juice gunks bulding up. From my experience, that usually means the popping motion of the juice or the heat expansion of the wire (or both) has cause the screws to come a little loose off the wire. Tightening it again usually does the trick.

It is normal for a little variance, but 1.8 jumping to 3.8 is definitely some loose contact.

 

[Niko49]

Thanks for the responses. I got my glass tank in and ended up building a new coil and rolling a new wick. I have since been steady at 1.6ohms with no changes. The only thing I did differently this time was pull the top part of the wick and coil closer to the positive post before tightening it down.


On a side note, The glass tank has fixed my "bent" issue. I believe the standard plastic tanks that come with the AGA's are not quite level and it was giving it the "bent" look.