Patent 7298127 was granted and assigned to Smiths Detection on November, 2007 by the United States Patent and Trademark Office.
Particle detection and characterizing apparatus has an insulating tube along which the particles flow. Five electrodes spaced along the outside of the tube are connected via amplifiers to a processor arranged to measure the charge on the particles. The apparatus also includes a laser and photomultiplier tube arranged to measure the size of the particles so that the nature of the particles can be characterized from their electrical charge and size.