Carbon Arc Lamp
Date: 1920 - 1940 |
Very powerful light sources were required for large format photomicrography, metallurgical microscopy, ultramicroscopy and fluorescence microscopy. Carbon arc lamps were the most convenient sources to use. Line power was attached using a large resistor. Both the lamp and resistor generated large amounts of heat. Since the arc was an intense source of both visible and ultraviolet light, it had to be viewed through a shield and a heat absorbing glass was necessary in the optical system. more...