US 10,890,516 B2
Forward scatter in particulate matter sensor
Ouyang Yang, Shanghai (CN); Lu Tian, Suzhou (CN); Chen Feng, Snohomish, WA (US); Lu Jinnan, Suzhou (CN); Rui Hou, Suzhou (CN); and Tao Chen, Shanghai (CN)
Assigned to Honeywell International Inc., Charlotte, NC (US)
Filed by Honeywell International Inc., Morris Plains, NJ (US)
Filed on Sep. 26, 2018, as Appl. No. 16/143,438.
Application 16/143,438 is a continuation of application No. 15/423,302, filed on Feb. 2, 2017, abandoned.
Prior Publication US 2019/0025180 A1, Jan. 24, 2019
Int. Cl. G01N 15/06 (2006.01); G01N 21/53 (2006.01); G01N 21/47 (2006.01); G01N 15/00 (2006.01)
CPC G01N 15/06 (2013.01) [G01N 21/53 (2013.01); G01N 21/534 (2013.01); G01N 2015/0046 (2013.01); G01N 2015/0693 (2013.01); G01N 2021/4707 (2013.01); G01N 2201/0612 (2013.01); G01N 2201/08 (2013.01); G01N 2201/12 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A particulate matter sensor comprising:
an airflow channel;
a laser diode for producing a light beam;
an airflow generator configured to generate airflow into the airflow channel;
a photodiode configured to receive light produced by the laser diode;
a solid body waveguide positioned between the laser diode and the photodiode, wherein the solid body waveguide is configured to direct light scattered by particulate matter within the airflow channel toward towards the photodiode, the solid body waveguide defines a concave waveguide inlet surface and a concave waveguide outlet surface, and
wherein the concave waveguide inlet surface is configured to receive light scattered by the particulate matter within the airflow channel and the concave waveguide outlet surface is configured to deliver at least some of the scattered light to the photodiode;
wherein the solid body waveguide extends to and defines one or more side walls of a light collecting lumen that extends at least partially through the solid body waveguide from the concave waveguide inlet surface toward the concave waveguide outlet surface and forms an opening through the concave waveguide inlet surface, wherein the opening through the concave waveguide inlet surface is aligned with the light beam of the laser diode; and
a computing device coupled to the photodiode having a processor and a memory storing instructions which, when executed by the processor, determines a mass concentration of particles in the airflow channel based on an output of the photodiode.