Easy build ESD, Static Electric Detector and also Ion detector Possibly <br /> <br />Ridiculously Sensitive Electric Charge Detector <br />http://amasci.com/emotor/chargdet.html <br /> <br />Static electricity detector easy to make <br />http://www.observationsblog.com/sciencetechnologyexperiments/-static-electricity-detector-easy-to-make <br /> <br />Build An Ion Detector and Test Your Negative Ionizer <br />by Vincent Vollono from "Spring 1994 Electronics Hobbyists Handbook" <br />https://www.naturalsolutions1.com/iondetect.htm
