Compact, low cost particle sensor
OwnerRoger L. Ungerinventor
Life of this patent
Estimating the term…
Abstract
A compact, low cost particle sensor utilizing a photodetector (31) which directly collects light scattered by particles (33) entrained in a fluid traversing a beam of light (32). The beam of light (32) is aligned such that it is in close proximity to the photo detector (31). The beam of light (32) is typically provided by a laser and associated focusing/collimating optics. The beam of light (32) intersects a portion of the fluid flow permitting a low pressure drop system and fluid flow generated by a low cost, low pressure device such as an axial fan (50).
Claims18
A particle sensor using scattered light to detect and size particles entrained in air drawn from an environment into the particle sensor, said particle sensor comprising;
- a beam of light a photodetector in close proximity to said beam of light;
- an air flow passage located upstream of said beam of light;
- an air flow means for generating air flow through the particle sensor;
- wherein said beam of light intersects only a portion of said air flow.
A particle sensor using scattered light to detect and size particles entrained in air drawn from an environment into the particle sensor, said particle sensor comprising;
- a light source generating a beam of light;
- a photodetector in close proximity to said beam of light;
- an air flow passage located above upstream of said beam of light;
- an air flow means for generating air flow through the particle sensor;
- an electronic means for converting the output of said photodetector into pulses and analyzing those pulses for count and size information;
- wherein said beam of light intersects only a portion of said air flow.
A method using scattered light for detecting and sizing particles entrained in an air flow, the method comprising steps of;
- generating a beam of light;
- directing said beam of light to pass above a photodetector in proximity to said photodetector;
- directing the air flow above the photodetector so that a portion of said air flow intersects said beam of light in proximity to said photodetector;
- analyzing the output of the photodetector to count and size particles in the air flow.
Dependencies are inferred from the claim text.