GB190407775A - Improvements in Instruments for Rendering Visible the Luminous Effects Produced by Radio-active Substances. - Google Patents

Abstract

7775. Glew, F. H. April 2. Radio-active substances, instruments for observing effects of.-The radio-active substance is arranged on one side of a transparent fluorescent or phosphorescent screen, and the luminous effects of its rays are observed through a lens on the other side of the screen. In Fig. 1, the screen A is removably held by resilient fingers b<2> on a casing b carrying the eyepiece b<1>. It is made by sifting zinc sulphide, willemite, natural zinc silicate, or other phosphorescent or fluorescent substance over a glass, mica, celluloid, or similar transparent plate coated with an adhesive material a. The radioactive substance is caused to adhere to the coated surface c of a piece C of glass or cardboard and may be used in the solid or gaseous state or in solution. Or a plate of pitchblende may be employed. The piece C may be connected to the screen by adhesive strips a', or it may be placed in contact with the screen, The space a<X> may be exhausted, or may contain air or other gas or vapour. Or it may be adapted to take a stencil, Fig. 4, cut to the outline of a landscape or otherwise to limit the area of visible scintillations to some pattern. A stencil may be fixed permanently in contact with the screen, or the radio-active plate, or both. Instead of using a stencil, a design may be painted on the screen or plate, or both, or the radio-active substance may be mixed with varnish or gum and painted on the screen. The lens B, Fig. 2, may comprise a cylindrical piece of glass with a rounded end, the fluorescent substance a being applied to its flat end. Or it may be spherical, the radio-active plate being correspondingly curved. The parts of the device may be disconnectible to adapt them to fit into a box when not in use.