(under subclass 319) Subject matter which generally includes in at least one of the beams an optical member, such as a wedge, responsive to the comparison means to automatically equalize the intensities of both beams, or which includes an electrical member responsive to the comparison means to electrically create a null condition in the comparison means.
SEE OR SEARCH THIS CLASS, SUBCLASS:
434+, for similar detection and comparison circuits which control the equalization of the light intensity only of plural beams, at least one beam being transmitted through a sample.
SEE OR SEARCH CLASS
250, Radiant Energy,
204, for photo-electric circuits which adjust an optical system to balance light intensity in plural paths; and subclasses 336.1+ for methods and apparatus involving similar devices responsive to invisible radiation.
315, Electric Lamp and Discharge Devices: Systems, 151, and 158 wherein a radiant energy device controls an electric lamp load device.
318, Electricity: Motive Power Systems,
560+, for electric motor follow-up systems which include a self-balancing network.
