| roentgenometer | 1. A forestaff. 2. <physics> An instrument designed for measuring the mechanical effect of radiant energy. It consists of a number of light discs, blackened on one side, placed at the ends of extended arms, supported on an a pivot in an exhausted glass vessel. When exposed to rays of light or heat, the arms rotate. Origin: L. Radius radius: cf. F. Radiometre. Source: Websters Dictionary (01 Mar 1998) |
|---|