The Photo conductive effect

Shows how the photo-conductive cell is highly sensitive to infra-red radiation. Illustrates various methods of detecting and measuring such radiation; history of research into the photo-conductive effect - Willoughby Smith’s experiments and Adam’s and Day’s work; composition of a photo-conductive cell and its working; the distance in spectral response curve between the different substances; operation of guided missiles, steel furnaces, and medical analysis.