(under subclass 336.1) Subject matter which includes a body of fluent material, a radiant energy source, and a detector responsive to the source arranged so that the body of fluent material is located in the radiation path between the source and detector or the body of fluent material supports either the source or detector, wherein the detector produces an output representative of the height or depth of the body of fluent material and methods corresponding to the apparatus.
SEE OR SEARCH THIS CLASS, SUBCLASS:
306+, for containing fluent material level signalling where charged particles are used to sense the level of the material.
SEE OR SEARCH CLASS
73, Measuring and Testing,
290+, for liquid level or depth gauges not using invisible light.
116, Signals and Indicators,
109+, and 227+ for mechanical liquid level indicators.
137, Fluid Handling,
386+, for liquid level responsive or maintaining system.
340, Communications: Electrical,
612+, for fluent or pulverized material level not using invisible light.
