Electret gamma X-ray low level dosimeter

This patent describes an apparatus for monitoring gamma or X-ray radiation. It comprises a chamber having an inner surface which is electrically conductive, an electret positioned within the chamber for holding an electrostatic charge which collects ions formed in the chamber by bombardment of gamma or X-ray radiation, and a removable means connected with the chamber for mounting the electret, the chamber enclosed in a radioactive gas tight container