(under subclass 218) Subject matter including an optical element which is adjustable or removable to selectively vary the light transmission to the light responsive device or including an adjustable resistance in the electrical coupling between the device and the meter or indicator to absorb a portion of the energy otherwise passing to the meter or indicating device to provide selective sensitivity and thus a plurality of operating meter or indicator ranges.
SEE OR SEARCH THIS CLASS, SUBCLASS:
226, for electrical circuitry coupling the detector and indicator.
228, for photoelectric type photometers with movable scales.
