Patent ID: 6606899
Filing Date: 2003-08-19
Classification: G01N

Abstract:
A device for measuring a total concentration of impurities in a sample gas, comprising a housing having an inlet to allow said sample gas at atmospheric pressure to continuously enter said housing, an emitter to continuously generate positive ions from said sample gas, a field gradient to continuously accelerate substantially all of said positive ions continuously toward a collector until substantially all of said positive ions reach said collector, said emitter having a higher voltage than the collector, said collector adapted to measure total positive ions in said sample gas, at least one grid electrode located in said housing between said emitter and said collector to facilitate ions in moving from said emitter to said collector, said emitter has a potential of a first voltage applied thereto and at least one of said at least one grid electrode has a potential of a second voltage applied thereto, where said second voltage is less than said first voltage, and an outlet to allow said sample gas to exit said housing, whereby a change in total positive ions received by said collector indicates a change in said total concentration of impurities in said sample gas.