Patent ID: 7836751
Filing Date: 2010-11-23
Classification: B03C,B60H,G01N

Abstract:
1. An ultra fine particle sensor for sensing airborne particles with a diameter in a range of approximately 5-500 nm, comprising: an air inlet for entry of a flow of ultra fine particles; a concentration variation section capable of causing a variation of the concentration of ultra fine particles between at least a first concentration level and a second concentration level during at least one time interval; a particle sensing section capable of producing a measurement signal being an electric current varying between at least a first current level corresponding to the first concentration level and a second current level corresponding to the second concentration level, and an evaluation unit capable of deriving the particle number concentration entering the air inlet by comparing the first current level and the second current level, the particle number concentration being associated with ultra fine particles with a diameter of about 5 nm or larger, wherein the evaluation unit is further capable of deriving the particle length concentration from the first current level, the particle length concentration being associated with ultra fine particles with a diameter of about 5 nm or larger.