(under subclass 51) Subject matter which includes a body of fluent material, an X-ray or gamma ray 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 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.
250, Radiant Energy,
306+, for contained fluent material level signalling where charged particles are used to sense the level of the material.
340, Communications: Electrical,
612+, for fluent or pulverized material level signalling not using invisible light.
