Originally Posted by OchnofConcrete

get a multimeter from walmart if you haven't yet. they've got nice ones.. should be red protective corners with black facing. think they're 30 or 50. extremely handy. the Omega symbol is for Ohms testing... resistance testing
the volts and other stuff, you use for testing the actions of the sensors via your FSM's instructions.
the ohms are for testing the continuity of the circuit or wire you are testing.