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US 2015/0102935 A1Published application
Smoke detector with external sampling volume and ambient light rejection
AssigneeValor Fire Safety, LLC
InventorMatthew Erdtmann
Life of this patent
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Abstract
In accordance with certain embodiments, a smoke detector determines the presence of smoke particles outside its housing based on measurements of light detected at different wavelengths and corrected based on an ambient light level.
Claims23
-147. (canceled)
A method of smoke detection utilizing a smoke detector comprising (a) a housing, (b) one or more light emitters, and (c) one or more light detectors, the method comprising:
- acquiring a measurement of light including a first wavelength originating outside the housing while emitting light of approximately the first wavelength with at least one said light emitter;
- acquiring a measurement of light including a second wavelength originating outside the housing while emitting light of approximately the second wavelength with at least one said light emitter, the second wavelength being longer than the first wavelength;
- detecting an ambient light level outside of the housing;
- correcting the measurement of light including the first wavelength based at least in part on the detected ambient light level, thereby producing a corrected first-wavelength measurement;
- correcting the measurement of light including the second wavelength based at least in part on the detected ambient light level, thereby producing a corrected second-wavelength measurement;
- and
- determining the presence of smoke particles outside the housing based on a ratio of the corrected first-wavelength measurement to the corrected second-wavelength measurement.
4 more elements
Dependencies are inferred from the claim text.