Fluorescent optical liquid level sensor
October 28, 2018. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References H1364 Optical sensor constituting a light transmissive medium with luminescent particles Light attenuation sensing apparatus for measuring physical parameters and other variables utilizing a light conducting member containing a fluorescent material Fibre optic sensor for liquid level and other parameters Fiber optic liquid level sensor Fibre optic sensor for the continuous measurement liquids level and other parameters Fiber optic continuous liquid level sensor Plural wavelength fiber optic liquid level sensor for multiple liquids Patent #: 5164608 InventorAssigneeApplicationNo. 181576 filed on 10/28/1998US Classes:250/577, Volume or level250/227.14, Condition responsive light guide (e.g., light guide is physically affected by parameter sensed which results in light conveyed to the photocell)250/227.25, Fluid coupling250/904With single light guide element to guide light in a continuous pathExaminersPrimary: Lee, John D.Attorney, Agent or FirmInternational ClassesG01N 015/06H01J 005/16 904 905 907 AbstractA liquid level sensor comprising a transparent waveguide containing fluorescent material that is excited by light of a first wavelength and emits at a second, longer wavelength. The upper end of the waveguide is connected to a light source at the first wavelength through a beveled portion of the waveguide such that the input light is totally internally reflected within the waveguide above an air/liquid interface in a tank but is transmitted into the liquid below this interface. Light is emitted from the fluorescent material only in those portions of the waveguide that are above the air/liquid interface, to be collected at the upper end of the waveguide by a detector that is sensitive only to the second wavelength. As the interface moves down in the tank, the signal strength from the detector will increase.Field of SearchVolume or levelFluent material in optical path Light conductor Condition responsive light guide (e.g., light guide is physically affected by parameter sensed which results in light conveyed to the photocell) Causing light spectral frequency/wavelength change With light chopping or modulation With spectral frequency/wavelength discrimination With coupling enhancement means Fluid coupling OPTICAL LIQUID LEVEL SENSORS With gap between light guide elements (includes open light path preset) With closed light path preset With prism contacting liquid OPTICAL WAVEGUIDE SENSOR HAVING PARTICULAR OPTICAL CHARACTERISTIC MODIFYING CHEMICAL COMPOSITION Of waveguide core Organic Of waveguide cladding Organic | |
