The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 2002
Filed:
Aug. 14, 2000
Klaus Willeke, Cincinnati, OH (US);
Other;
Abstract
A method and apparatus are provided for measuring the aerodynamic particle size distribution of airborne particles by drawing the particles through a device which continuously or intermittently changes the aerodynamic cut of the particles entering an aerosol sensor. Sensing is performed by optical sensors such as aerosol photometry or optical single particle size spectrometry or by other sensors that measure particle concentration remaining in the aerosol flowing from the cut device. Preferably, the cut device includes a rotational element that centrifugally removes particles of larger aerodynamic size than that determined by a cut setting, which can be varied by varying the rotational speed of the cut element. Preferably also, the rotary element does not alone determine the flow rate of the aerosol through the cut device, but a separate pump or flow restriction controls the time the aerosol remains in the cut device and maintains the flow rate through the device at a preferably constant level.