Patent ID: 7640782

Claim:
An apparatus for calibrating a concentration sensor for sensing concentration of vaporized hydrogen peroxide, said apparatus comprising: an enclosure defining a chamber; a first temperature sensor for generating a first signal indicative of the temperature within the chamber; a vessel defining a cavity, said vessel including isolation means movable between a closed position for isolating the cavity from the chamber and an open position wherein the cavity is in fluid communication with the chamber; first supply means for supplying an aqueous solution of liquid hydrogen peroxide to the cavity; a first concentration sensor for generating a second signal indicative of a concentration of liquid hydrogen peroxide within the cavity; a controller storing data for correlating a concentration of liquid hydrogen peroxide at a predetermined temperature to a concentration of vaporized hydrogen peroxide, said vaporized hydrogen peroxide being derived from said aqueous solution of liquid hydrogen peroxide, wherein said controller includes: means for receiving the first signal generated by the first temperature sensor indicative of the temperature within the chamber and the second signal generated by the first concentration sensor indicative of the concentration of liquid hydrogen peroxide within the cavity; means for moving said isolation means from the closed position to the open position, thereby releasing vaporized hydrogen peroxide into said chamber; means for receiving a third signal generated by a second concentration sensor located within said chamber, said third signal indicative of a measured vaporized hydrogen peroxide concentration inside said chamber; means for determining an actual concentration of vaporized hydrogen peroxide inside said chamber using said first signal, said second signal and said stored data; means for comparing said measured concentration to said actual concentration to determine an error value; and means for calibrating said second concentration sensor in accordance with the determined error value.