I've known "free zoners" who have their own E-meters.<p>See this write-up<p><a href="https://www.cs.cmu.edu/~dst/Secrets/E-Meter/Mark-VII/" rel="nofollow noreferrer">https://www.cs.cmu.edu/~dst/Secrets/E-Meter/Mark-VII/</a><p>and note that modern E-meters contain a microprocessor that samples what the meter is reading and sends it out a serial port so an E-Meter can be monitored remotely.<p>It's quite an interesting device which is designed to be as mind boggling as possible. I found out long after I left that the meter in an E-Meter is a special underdamped meter that was manufactured at a factory near the airport in my hometown of Manchester, NH [1] (not far from where Origin games had a dev office in the Ultima era); one consequence of that is that if something changes the meter will bob back and forth a long time so you are seeing an unholy combination of the input signal plus the behavior of the needle. The galvanic skin response that it measures is both real and unreliable, it really will respond to your emotions but it will also sometimes respond for no obvious reason. With the doctrine of "the meter is always right" this is a recipe for seriously gaslighting people. I borrowed one from a friend years ago and could not make sense of what it did at all. (For somebody anxious I'm actually really good at biofeedback)<p>[1] <a href="https://www.cs.cmu.edu/~dst/Secrets/E-Meter/koos-answered.txt" rel="nofollow noreferrer">https://www.cs.cmu.edu/~dst/Secrets/E-Meter/koos-answered.tx...</a>