Claims
- 1. A liquid-level monitor for monitoring the level of a boundary between a liquid and another fluid within a vessel, said liquid having a first specific gravity, said fluid having a second specific gravity less than said first specific gravity, said monitor comprising:
- a light source for providing source light;
- photodetector means for providing a characterization of return light, said characterization including whether or not said return light meets a predetermined intensity criterion, said photodetector means responding more sensitively to the return light frequency than to the source light frequency;
- optical fiber means for guiding said source light to a location set within said vessel and guiding said return light from said location set to said photodetector means, said set including at least one location, each location of said set corresponding to a respective level of said boundary within said vessel, said optical fiber means including at least one length of optical fiber through which said source light travels in one direction and said return light travels in an opposing direction;
- a float disposed at said boundary, said float having a third specific gravity between said first specific gravity and said second specific gravity, said float converting said source light into said return light meeting said intensity criterion, said float being fluorescent so that the frequency of said return light is different from the frequency of said source light; and
- guide means for confining movement of said float to a vertically extending path.
- 2. A liquid-level monitor for monitoring the level of a boundary between a liquid and another fluid within a vessel, said liquid having a first specific gravity, said fluid having a second specific gravity less than said first specific gravity, said monitor comprising:
- a light source for providing source light;
- photodetector means for providing a characterization of return light, said characterization including whether or not said return light meets a predetermined intensity criterion;
- optical fiber means for guiding said source light to a location set within said vessel and guiding said return light from said location set to said photodetector means, said set including plural locations, each location of said set corresponding to a respective level of said boundary within said vessel, said optical fiber means including at least one length of optical fiber through which said source light travels in one direction and said return light travels in an opposing direction;
- a float disposed at said boundary, said float having a third specific gravity between said first specific gravity and said second specific gravity, said float converting said source light into said return light meeting said intensity criterion;
- guide means for confining movement of said float to a vertically extending path; and
- boundary motion determination means being coupled to said photodetector means for detecting when said boundary crosses each of said levels, said boundary motion determination means including timing means so that the time interval between level indications can be determined, said boundary motion determination means including calculation means for calculating the rate at which said boundary is moving from said time interval.
Parent Case Info
This is a continuation application of U.S. patent application Ser. No. 08/113,162, filed Aug. 27, 1993, now abandoned.
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Continuations (1)
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Number |
Date |
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Parent |
113162 |
Aug 1993 |
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