Patent ID: 7876421
Filing Date: 2011-01-25
Classification: G01J

Abstract:
1. Light intensity measuring apparatus for measuring light from a distant light source comprising: a telephotometer having a lens system including an objective lens mounted at one end of a longitudinal body and a light energy detector having an information output communication conduit, the light energy detector mounted to receive light energy from a distant light source, the light energy entering the telephotometer through the objective lens; a light metering valve for controlling the field of view at the distant light source and limiting the angular range of acceptance of light rays at the light metering valve, the valve located in the body of the telephotometer at the focal surface location of the objective lens; a controller, the controller including a digital processor, in communication with the light energy detector through the communications conduit; a range finder for determining the distance to the light source, the range finder having electronic communication capability in communication with the controller, the range finder aligned substantially longitudinally with the body of the telephotometer.