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:
Apr. 22, 2014
Filed:
Oct. 26, 2009
Johan Marra, Eindhoven, NL;
Johan Marra, Eindhoven, NL;
Koninklijke Philips N.V., Eindhoven, NL;
Abstract
A device is presented that is capable of recording the evolution over time of the characteristics of a size distribution of electrically-charged airborne particles in an airflow. The device comprises an air inlet, a particle charging unit, a concentration variation section, a particle sensing section and a data evaluation unit. Specifically, the particle sensing section of the device generates at least two serially obtained measurement signals Iand Ifrom which the data evaluation unit can infer values for both the average particle diameter dand the number concentration N of the size distribution of electrically-charged airborne particles. Reliable values can be obtained for N and dunder both stationary conditions and transient conditions with respect to the characteristics of the particle size distribution due to the condition that the change of the inferred average particle diameter dwith respect to a reference particle diameter dis bounded by a set maximum change. This imposed condition markedly reduces scatter in the inferred values for dp,av and N as a function of time, while still allowing transient characteristics with respect to both N and dto become visible in the course of time, without having to rely on averaging procedures and/or device hardware adaptations.