Abstract: The disclosure is directed at apparatus for portable PM2.5 monitoring including a PM2.5 sampling device including a housing portion for collecting and separating air-borne particulate matter, an inlet port, connected to the housing portion, for receiving the air-borne particulate matter, a core portion, located within the housing portion, the core portion assisting in generating a cyclonic airflow pattern to produce a uniflow system for separating particulate matter below a predetermined size from particulate matter above a predetermined size within the air-borne particulate matter, and an outlet port for receiving the particulate matter below the predetermined size; a particle counter, connected to the outlet port, for receiving the particulate matter smaller than the predetermined size and for determining a mass of the particulate matter below the predetermined size; and a processor for determining a PM2.5 level based on the mass of the particulate matter below the predetermined size.

Abstract: The disclosure is directed at apparatus for portable PM2.5 monitoring including a PM2.5 sampling device including a housing portion for collecting and separating air-borne particulate matter, an inlet port, connected to the housing portion, for receiving the air-borne particulate matter, a core portion, located within the housing portion, the core portion assisting in generating a cyclonic airflow pattern to produce a uniflow system for separating particulate matter below a predetermined size from particulate matter above a predetermined size within the air-borne particulate matter, and an outlet port for receiving the particulate matter below the predetermined size; a particle counter, connected to the outlet port, for receiving the particulate matter smaller than the predetermined size and for determining a mass of the particulate matter below the predetermined size; and a processor for determining a PM2.5 level based on the mass of the particulate matter below the predetermined size.

Abstract: A cyclone includes a cylindrical housing and has an inner diameter D. An inlet is near a first end of the housing. A deflection member can be positioned within the first end or the second end of the housing, depending on whether the cyclone is uniflow or reverse flow. An outlet tube is positioned within and extends from a second end or the first end of the housing (depending on whether uniflow or reverse flow). A bunker is formed between the outlet tube and an inner wall of the housing in a uniflow design and between the deflection member and the housing in a reverse flow design, and collects particles separated from an inlet gas stream. A gap between the deflection member and the outlet tube has a length in the range of approximately 0.4*D to 0.8*D. The length of the bunker is approximately greater than or equal to 1.5*D.

Abstract: A cyclone includes a cylindrical housing and has an inner diameter D. An inlet is near a first end of the housing. A deflection member can be positioned within the first end or the second end of the housing, depending on whether the cyclone is uniflow or reverse flow. An outlet tube is positioned within and extends from a second end or the first end of the housing (depending on whether uniflow or reverse flow). A bunker is formed between the outlet tube and an inner wall of the housing in a uniflow design and between the deflection member and the housing in a reverse flow design, and collects particles separated from an inlet gas stream. A gap between the deflection member and the outlet tube has a length in the range of approximately 0.4*D to 0.8*D. The length of the bunker is approximately greater than or equal to 1.5*D.