System and method for determining concentration of sterilant

1. A vapor decontamination system for decontaminating a defined region, said system comprising:

a chamber defining a region;

a generator for generating vaporized hydrogen peroxide from a solution of hydrogen peroxide and water;

a closed loop circulating system for supplying said vaporized hydrogen peroxide to said region;

a destroyer for breaking down said vaporized hydrogen peroxide;

a sensor downstream from said destroyer operable to sense moisture in said system and provide electrical signals indicative thereof; and

a controller that determines the presence of vaporized hydrogen peroxide in said region based upon said electrical signals from said sensor.

2. A vapor decontamination system as defined in claim 1 , wherein said sensor is a humidity sensor.

3. A vapor decontamination system as defined in claim 1 , wherein said controller is operable to determine the concentration of vaporized hydrogen peroxide in said region based upon said electrical signals from said sensor.

4. A vapor decontamination system as defined in claim 1 , wherein said generator is a vaporizer.

5. A vapor decontamination system as defined in claim 1 , further comprising:

a blower within said closed loop circulating system, said blower operable to circulate air through said closed loop circulating system;

a dryer disposed within said closed loop circulating system between said destroyer and said generator, said dryer operable to remove moisture from said circulating system; and

a heater within said closed loop circulating system upstream from said generator for heating air flowing through said circulating system.

6. In a decontamination system for decontaminating a region, said system having a generator for generating vaporized hydrogen peroxide, a closed loop system for supplying the vaporized hydrogen peroxide to said region and a destroyer for breaking down the vaporized hydrogen peroxide, a sensor for detecting the humidity in said system downstream from said destroyer, and a controller that determines the presence of vaporized hydrogen peroxide in said region based upon data from said sensor.

7. A decontamination system as defined in claim 6 , wherein said controller is operable to determine the concentration of hydrogen peroxide in said region.

8. A decontamination system as defined in claim 7 , wherein said sensor is a humidity sensor.

9. A method of determining the presence of vaporized hydrogen peroxide (VHP) in a region, comprising the steps of:

providing a sealable region having an inlet port and an outlet port, and a closed loop conduit having a first end fluidly connected to the region inlet port and a second end fluidly connected to the region outlet port;

re-circulating a flow of a carrier gas into, through and out of said region and around the closed loop conduit;

delivering vaporized hydrogen peroxide into the re-circulating carrier gas flow upstream of the region inlet port;

destroying the vaporized hydrogen peroxide at a first location downstream from the region outlet port;

monitoring the temperature and humidity at a second location downstream from said first location; and

determining a presence of vaporized hydrogen peroxide in said region based upon the humidity readings at said second location.

10. A method as defined in claim 9 , wherein said carrier gas is air.

11. A method as defined in claim 9 , wherein said destroying step includes catalytically decomposing the hydrogen peroxide vapor into water and oxygen.

12. A closed loop, flow through method of vapor phase decontamination in a sealable chamber or region having an inlet port and an outlet port, and a closed loop conduit fluidly connecting the outlet port to the inlet port, the method comprising the steps of:

re-circulating a flow of a carrier gas into, through and out of the chamber, and through the closed loop conduit;

supplying vaporized hydrogen peroxide into the re-circulating carrier gas flow;

destroying the vaporized hydrogen peroxide to form water and oxygen at a first location downstream from said outlet port;

monitoring the relative humidity at a second location downstream from said first location; and

estimating the concentration of vaporized hydrogen peroxide in said region based upon the relative humidity at said second location.

13. A closed loop, flow through method as defined in claim 12 , wherein said carrier gas is air.

14. A closed loop, flow through method as defined in claim 12 , wherein said destroying step includes catalytically decomposing the hydrogen peroxide vapor into water and oxygen.

15. A closed loop, flow through vapor phase decontamination system, comprising:

a sealable chamber having an inlet port and an outlet port;

a closed loop conduit system having a first end fluidly connected to said inlet port and a second end fluidly connected to said outlet port;

a blower connected to said conduit system for re-circulating a carrier gas flow into, through and out of the chamber;

a vaporizer for delivering vaporized hydrogen peroxide into said carrier gas flow upstream of said inlet port;

a destroyer downstream of said outlet port for converting the vaporized hydrogen peroxide in water and oxygen;

a sensor downstream of said destroyer for detecting humidity; and

a processing unit that monitors the humidity level downstream of said destroyer and determines the concentration of vaporized hydrogen peroxide in said chamber based upon said humidity level.