Non-dispersive mid-infrared sensor for vaporized hydrogen peroxide
First Claim
1. A method of microbial or chemical decontamination comprising:
- exposing an item to be microbially or chemically decontaminated to a multi-component vapor which includes a gaseous oxidant and a second vapor component; and
detecting the gaseous oxidant in the multi-component vapor including;
directing light through the multi-component vapor, the directed light including light of at least a first wavelength range where the gaseous oxidant absorbs but at which the second vapor component does not significantly absorb, the first wavelength range including one or more wavelengths between about 7500 and 8400 nanometers, detecting the absorbance of light which has passed through the vapor in the first wavelength range, and determining the concentration of the gaseous oxidant in the multi-component vapor from the detected absorbance.
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Accused Products
Abstract
A sterilization system (14) includes a sensor (10) for detection of a component, such as hydrogen peroxide vapor, in a multi-component vapor, such as a mixture of vapor hydrogen peroxide and water supplied to a chamber (12) of the system. The sensor preferably uses a wavelength range in which hydrogen peroxide strongly absorbs but other components of the vapor, such as water, do not. A suitable wavelength for detection of hydrogen peroxide is from about 7500 to about 8400 nm, since there is little absorption by water in this range. This avoids the need to use complex subtraction procedures normally used to remove the contribution of water from detected absorbance measurements. A control system (16, 30) controls operating conditions of the sterilization system, such as a heater (82), pressure release valves (74), vaporization rate of hydrogen peroxide by a vaporizer (22), and the like to maintain optimum sterilization conditions within the chamber.
76 Citations
25 Claims
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1. A method of microbial or chemical decontamination comprising:
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exposing an item to be microbially or chemically decontaminated to a multi-component vapor which includes a gaseous oxidant and a second vapor component; and
detecting the gaseous oxidant in the multi-component vapor including;
directing light through the multi-component vapor, the directed light including light of at least a first wavelength range where the gaseous oxidant absorbs but at which the second vapor component does not significantly absorb, the first wavelength range including one or more wavelengths between about 7500 and 8400 nanometers, detecting the absorbance of light which has passed through the vapor in the first wavelength range, and determining the concentration of the gaseous oxidant in the multi-component vapor from the detected absorbance. - View Dependent Claims (2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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4. A method of microbial or chemical decontamination comprising:
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exposing an item to be microbially or chemically decontaminated to a multi-component vapor which includes a gaseous oxidant and water; and
detecting the gaseous oxidant and water in the multi-component vapor including;
directing light through the multi-component vapor, the directed light including light of a first wavelength range and a second wavelength range, the first wavelength range being where the gaseous oxidant absorbs but at which water does not significantly absorb, the first wavelength range including one or more wavelengths between about 7500 and 8400 nanometers, the second wavelength range being spaced from the first wavelength range, where water absorbs and the gaseous oxidant does not significantly absorb, the second wavelength range being in the range of from about 5200 nanometers to about 7200 nanometers, detecting the absorbance of light which has passed through the vapor in the first wavelength range, and determining the concentration of the gaseous oxidant in the multi-component vapor from the detected absorbance in the first wavelength range, detecting the absorbance of light in the second wavelength range, and determining the concentration of water in the multi-component vapor from the detected absorbance in the second wavelength range.
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17. A method of microbial or chemical decontamination comprising:
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exposing an item to be microbially or chemically decontaminated to a multi-component vapor which includes a gaseous oxidant and a second vapor component;
directing light through a sensor system including a transmitting portion which directs the light through the multi-component vapor and a receiving portion which receives light which has passed through the multi-component vapor, louvers being provided intermediate the transmitting portion and the receiving portion which permit the vapor to pass through the directed light but which inhibit stray radiation from being detected, the directed light including light of at least a first wavelength range where the gaseous oxidant absorbs but at which second vapor component does not significantly absorb, the first wavelength range including one or more wavelengths between about 7500 and 8400 nanometers;
detecting the absorbance of light which has passed through the vapor in the first wavelength range; and
determining the concentration of the gaseous oxidant in the multi-component vapor from the detected absorbance.
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18. A method for determining the concentration of hydrogen peroxide and water in a multi-component vapor, the method including:
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directing light through the multi-component vapor, the light including wavelengths in a first wavelength range of the mid infrared spectrum at which hydrogen peroxide absorbs but at which water does not significantly absorb and wavelengths in a second wavelength range of the mid infrared spectrum at which water absorbs but at which hydrogen peroxide does not significantly absorb, the mid infrared spectrum being from 2000-10,000 nanometers;
detecting light which has passed through the multi-component vapor in the first wavelength range;
separately detecting light which has passed through the multi-component vapor in the second wavelength range; and
determining concentrations of water and hydrogen peroxide in the multi-component vapor from detected light in the first and second wavelength ranges.
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19. A decontamination system comprising:
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a chamber which receives items to be microbially decontaminated;
a source of a gaseous sterilant which supplies the gaseous sterilant to the chamber;
a sensor system including;
a transmitting portion which directs light through the gaseous sterilant; and
a receiving portion which receives light which has passed through the gaseous sterilant, the receiving portion including;
a first detector positioned to receive light which has passed through the gaseous sterilant, the first detector detecting light in a wavelength range of the mid-infrared spectrum at which a first component of the gaseous sterilant absorbs, the mid-infrared spectrum being from 2000-10,000 nanometers; and
a control system which controls conditions within the chamber in response to a signal indicative of the light detected by the first detector. - View Dependent Claims (20, 21)
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22. A decontamination system comprising:
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a chamber which receives items to be microbially decontaminated;
a source of a gaseous sterilant which supplies the gaseous sterilant to the chamber, the sterilant including a mixture of water vapor and vapor hydrogen peroxide;
a sensor system including;
a transmitting portion which directs light through the gaseous sterilant; and
a receiving portion which receives light which has passed through the gaseous sterilant, the receiving portion including;
a first detector positioned to receive light which has passed through the gaseous sterilant, the first detector detecting light in a wavelength range of from about 7500 to 8400 nm at which a first component of the gaseous sterilant absorbs, a second detector positioned to receive light which has passed through the gaseous sterilant, the second detector detecting light in a wavelength range of from about 5200 to 7200 nm at which a second component of the gaseous sterilant absorbs and the first component does not absorb; and
a control system which controls conditions within the chamber in response to a signal indicative of the light detected by the first detector.
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23. A decontamination system comprising:
- a chamber which receives items to be microbially decontaminated;
a source of a gaseous sterilant which supplies the gaseous sterilant to the chamber;
a sensor system including;
a transmitting portion which directs light through the gaseous sterilant;
a receiving portion which receives light which has passed through the gaseous sterilant, the receiving portion including;
a first detector positioned to receive light which has passed through the gaseous sterilant, the first detector detecting light in a wavelength range of the mid-infrared spectrum at which a first component of the gaseous sterilant absorbs, and an elongated polygonally cross sectional, apertured tube connected with the transmitting and receiving portions to maintain the transmitting and receiving portions in a fixed relationship; and
a control system which controls conditions within the chamber in response to a signal indicative of the light detected by the first detector. - View Dependent Claims (24, 25)
- a chamber which receives items to be microbially decontaminated;
Specification