Muokattu kuvasta: Geiger Muller counter, Svjo-2 [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons

https://commons.wikimedia.org/wiki/File:Geiger-Muller-counter-en.png