Every site I go to order a ohm meter that screws into 510 connection is SOLD OUT. So my Q is can I buy a Multimeter like from radio shack that does not have 510 threads/connection but has hand held pencil shaped detectors .... I'm probably describing wrong but you experts prolly know what I'm talking about. If you do can you just poke the positive in end of a atty, carto, tank etc.... and ground the other to device ?? or ?? how ? Thanks for taking time to help me.