Fab I had a thought (mind you I can't solder and have no idea how).
WHat about taking a 510 connector from someplace like madvapes and soldering on wires for postive and negative to the right parts of the connector. Then just connecting a standard multimeter to that using gator clips.
check it with no atty screwed on to get a baseline then screw in an atomizer and test again. subtract one from the other to get the ohms.
Yes, and you could also make up a special set of leads, with the short banana plugs on one end and the 510 connector on the other. This will help the accuracy of the readings by eliminating the tricky procedure of holding the probes on two different poles (one threaded, the other a center pin).
It would help a lot because sometimes you have to look at the reading for about 10 seconds until it settles down - this would be due to some capacitance in the circuit. It's not an unusual phenomenon.
The reason we have to recommend a multimeter is that there is really very little else available. Commercially available test equipment designed to test low ohms accurately is hundreds or even thousands of dollars and is massive overkill for our application. Mostly we just need something that can read 0 to about 6 ohms with about 2% accuracy. The device from MadVapes is perfect, but is not available in large enough numbers to be able to supply everyone.
I favour a cheap circuit that we can plug into our multimeters, and use the digital display. For example, you set the multimeter on the 20uA range and screw the atomiser onto the box attached to the multimeter. A reading of 2.63uA would be 2.63 ohms and so on. This is a cheaper alternative because the output device is usually the most expensive (eg panel meter) or the most complicated (digital display). We all have multimeters, so why not use them?
The problem is finding or designing a linear circuit that will output the range we need. I'm pretty sure there are people here on ECF that have the experience to knock one up quite quickly. I might have quick look at the cost of putting together the circuit I linked to. (I thunk a thought - Fasttech sell electrical components - must have a look!)