[NorthCarolinaPrepper takes us through building, charging, and using an expedient radiation meter, the Kearny Fallout Meter or KFM. It can be found in Appendix C of the book, Nuclear War Survival Skills by Cresson H Kearny, which is a free download. This device appears to be quite finicky so you need to be rather precise when building it. This is a two part video: part one is the building process, part two is about charging and use. For those who are worried about potential fallout from Fukushima or for any other nuclear event, such a device may prove invaluable.]
