What Rob says ^
Here's how I (used to) do it
I just put some single strand insulated copper leads on an extra RBA base I had and touch the terminal posts to get a reading.
Unfortunately that atty is now on my 60 something year old step dads REO I got for him about 2 months ago. He (and my 70 something year old mother) both quit smoking and vaping days apart. I gave my mom a REO and a cyclone atty.
They have not rebuilt the attys yet, but have come over for weekly rewicking and coil checks. They vape 24 mg nic base and their coils are fine.
Just Wednesday, I trained him to rewick both attys and check screw tightness. He did an excellent job with both.
I hate touching other people's mods and attys so next I'm gonna train him to rebuild their own coils. My mom may be better at that because she's into sewing and crafting - he's more the drywall repair type.
There's a lot of very simple videos for rebuilding and a very simple photo tutorial.
How bout I place a some here for you
Photo:
http://www.e-cigarette-forum.com/forum/showthread.php?t=413000
Video:
http://youtu.be/q8FyL2CTd-k
The guy that makes those vids has been using exclusively REOs for nearly 2 years. He was once a big puss about rebuilding and when he found how easy it was he became all evangelical on the subject
Here's a video on the grand too:
http://youtu.be/sNfog0ysbW0
You CAN easily and lazily rebuild. That and your REO and you'll be vaping like a rock starlet
Also note that a lot has changed in the last year or so since I made that vid
Here's how I do it now (of course it's even easier cause I'm lazy too

)
Making the coil:
http://youtu.be/rua_l_IpBWk
Mounting the coil:
http://youtu.be/Z0NuH93KvtY
Wicking the coil:
http://youtu.be/OQt8-EbWTZg