National Stock Number:
Federal Supply Class:
National Item Identification Number:
An inclosure, including two or more electrodes, in which a flow of electrons may occur through a vacuum or a contained gas. The electronic conduction takes place either by means of electrons emitted from a cathode or by ionization of the contained gas. Includes phototubes (photoemissive type only), Geiger-Mueller tubes, traveling wave tubes, cathode ray tubes and microwave tubes (Klystron, magnetron, or the like). Excludes items whose primary purpose is to produce light energy. Also excludes PHOTOELECTRIC CELL; and SEMICONDUCTOR DEVICE (as modified).