Detection of particle characteristics
First Claim
Patent Images
1. A particle detection system for including:
- a detection chamber adapted to receive an air sample;
first particle detection means including a first light source for illuminating a first volume of the air sample at at least a first wavelength, and a first light receiver having a field of view intersecting with the first volume for receiving light scattered from the detection chamber and outputting a first signal indicative of the scattered received light;
second particle detection means including a second light source for illuminating a second volume of the air sample at at least a second wavelength, and a second light receiver having a field of view intersecting with the second volume for receiving light scattered from the detection chamber and outputting a second signal indicative of the scattered received light;
light source activation means adapted to selectively activate the first light source in a first time period and the second light source in a second time period; and
processing means adapted to receive a first signal from the first light receiver and a second signal from the second light receiver corresponding to the first time period and process the received signals to generate a first output corresponding to the first time period corrected for background light; and
to receive a first signal from the first light receiver and a second signal from the second light receiver corresponding to the second time period and process the received signals to generate a second output corresponding to the second time period that is corrected for background light.
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Abstract
A method of detecting particles in an air flow is described. The method includes receiving a signal indicative of light intensity scattered from the air flow at a plurality of wavelengths and processing the signal indicative of the intensity of received light at each of the wavelengths and a corresponding wavelength dependent parameter to generate an output signal indicative of at least one characteristic of particles in the air flow. A particle detection system is also described.
21 Citations
7 Claims
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1. A particle detection system for including:
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a detection chamber adapted to receive an air sample; first particle detection means including a first light source for illuminating a first volume of the air sample at at least a first wavelength, and a first light receiver having a field of view intersecting with the first volume for receiving light scattered from the detection chamber and outputting a first signal indicative of the scattered received light; second particle detection means including a second light source for illuminating a second volume of the air sample at at least a second wavelength, and a second light receiver having a field of view intersecting with the second volume for receiving light scattered from the detection chamber and outputting a second signal indicative of the scattered received light; light source activation means adapted to selectively activate the first light source in a first time period and the second light source in a second time period; and processing means adapted to receive a first signal from the first light receiver and a second signal from the second light receiver corresponding to the first time period and process the received signals to generate a first output corresponding to the first time period corrected for background light; and
to receive a first signal from the first light receiver and a second signal from the second light receiver corresponding to the second time period and process the received signals to generate a second output corresponding to the second time period that is corrected for background light. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification