Method and systems for particle characterization using optical sensor output signal fluctuation
AssigneeSharp Laboratories of America, Inc.
InventorsYongji Fu, Deepak Ayyagari
Life of this patent
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Abstract
Methods and systems for particle characterization using a light fluctuation component of an optical sensor output signal. The use of the light fluctuation component enables particle characterization (e.g. provision of information on particle size, type and confidence) without requiring measurements at multiple wavelengths or multiple angles and using relatively lightweight calculations. The methods and systems allow integration of real-time airborne particle characterization into portable monitors. The methods and systems in some embodiments also use the output signal to further characterize particles through determination of particle density information.
Claims12
A system for particle characterization, comprising:
- a signal processor;
- and
- an optical sensor communicatively coupled with the signal processor, wherein the signal processor maintains associations between discrete standard deviation ranges and particle size categories representing discrete particle sizes, wherein higher standard deviation ranges are associated with larger particle sizes, and wherein the signal processor isolates a light fluctuation component of an output signal received from the optical sensor, computes a standard deviation of the light fluctuation component from samples taken at different times within a time section and classifies particles detected during the time section into a the particle size category associated with the standard deviation range within which the standard deviation falls.
A system for particle characterization, comprising:
- a signal processor;
- and
- an optical sensor communicatively coupled with the signal processor, wherein the signal processor maintains associations between discrete standard deviation profiles and particle type categories representing discrete airborne contaminants, and wherein the signal processor isolates a light fluctuation component of an output signal received from the optical sensor, computes a standard deviation of the light fluctuation component from samples taken at different times within a time section and classifies particles detected during the time section into the particle type category associated with the standard deviation profile that most closely matches the standard deviation.
A method for particle characterization, comprising the steps of:
- maintaining associations between discrete standard deviation ranges and particle size categories representing discrete particle sizes, wherein higher standard deviation ranges are associated with larger particle sizes;
- receiving an output signal from an optical sensor;
- isolating a light fluctuation component of the output signal;
- computing a standard deviation of the light fluctuation component from samples taken at different times within a time section;
- classifying particles detected during the time section into the particle size category associated with the standard deviation range within which the standard deviation falls;
- and
- displaying the category on an output interface.
Dependencies are inferred from the claim text.