Atty resistances not as advertised?

[TeeFour]

So I picked up a multimeter today. Decent one from radio shack, about 25 bucks. My eGo battery runs at 3.2V, my buzz at whatever I want to set it at. Then I decided to measure the resistances of my attys. I started with my standard 510s, one that came with the eGo, one from litecigusa, and one generic brand. All were around 2.2 ohm. My eGo mega atty was also at 2 ohm. My Joye and generic LR 510 atty advertised as 2 ohm were both 1.5. Is my multimeter off, or are the advertised resistances simply not all that accurate in other peoples' experiences?

 

[Icoth]

Were your atttys new or used? The resistance changes with time and I've found it also changes depending on how clean they are. I've had a Joye 510 that measured 2.2 or 2.3 when new go as low as 1.7 ohms. I think it's normal for new attys to vary a tenth or two, but much more than that sounds like they shipped the wrong product.

 

[WomanOfHeart]

Does your multimeter read 0 when you initially turn it on, or does it read a number such as .5? My multimeter always calibrates at .5, so an atty that reads 2.5 is actually 2.0.

 

[DaveP]

Short the leads of the meter when set to ohms. That will give you the combined resistance of the leads and the connections at the plugs. Deduct this value from your reading when checking resistance.

Once upon a time, when meters were analog, there was a thumbwheel or knob you could use to zero the meter with the leads shorted. Digital meters don't usually have this feature. I don't know why they don't incorporate a zero calibrate button that could be pressed while the leads are shorted to calibrate.

510 style batteries are regulated at 3.2 - 3.4 volts under load even though the unloaded battery output is 3.7vdc.

Check out this thread by Scottbee for some good info on battery voltages.
http://www.e-cigarette-forum.com/fo...ages-surprise.html?highlight=scottbee+voltage

 

[cskent]

I was ordering 1.5 ohm atty's for a long time from a particular vendor. I finally measured a few of them and they read 1.9 to 2.2 ohms. I got some 1.5's from another vendor and they're a different brand too and they measure 1.6 to 1.9 ohms. There's a noticeable difference between the two types. I don't think some vendors have bothered testing them for themselves and don't really know.