Patent ID: 7830510
Filing Date: 2010-11-09
Classification: G01N

Abstract:
1. An apparatus for detecting fibers in a gas comprising a light source producing a substantially parallel beam of light along a passageway through which said gas flows, a photo detector to detect light scattered from the light beam by a fiber in said gas, said passageway being formed into a separable body piece, an electrode system producing an oscillating electric field to cause said fiber to oscillate, said electrode system having electrodes embedded into an insulating plastic housing forming a subassembly, said subassembly being held in place in said separable body piece, said electrode system comprising a first pair of electrodes open to said passageway on a first side of the passageway coupled to a DC source only, and a second pair of electrodes open to said passageway on a second side of the passageway and spaced from the first pair of electrodes and connected to an AC source only, and said passageway having a cross-sectional area A 1 , and said beam of light having a cross-sectional area A 2 , the ratio of said areas, A 1 /A 2 , being in the range from 2 to 50.