I hear talk about the K2 and the MEL. And I don't see the draw on either of those. I've read the specifications on both 20-20khz, and the sensitivity level. Both are calibrated at 60hz which is honestly the worst possible frequency to calibrate at if you're looking for spirit manifestations. 60hz is the frequency of the US power sources, so you'll get ambient 60hz almost anywhere.
Both MEL and K2 have just a 5 position LED readout which does not give you a true indicator of the level of signal. I don't use EMF meters as a true source of evidence more as a sort of dowsing rod to give me a clue that we're in the right place.
I personally use the Ghost Meter, it has a good old fashioned analog meter on it so you can see subtle fluctuations in the level. Same frequency range as the others, and best of all its CHEAP! CHEAP is a great price where I'm concerned. Specially for a empirical piece of equipment. I got 4 of them, and I got them from Amazon. Here is the
LINK.
What I do tend to use more than anything is a little device I put together that lets you actually record the EMF signals. That way you can hear if they're just 60 cycle hum bleeding through from nearby power sources, some mechanical EMF noise, something from a digital source, or a real unexplained source.
Instructions for making one of those can be found in a forum post
HERE.