Air quality chamber: relative humidity and contamination controlled systems

A method for providing a controlled air quality environment within a device comprising the steps of:

• receiving air from an outside environment into a device housing, the housing including a reservoir disposed therein and a chamber separate from and in air-flow communication with the reservoir;
• controlling the relative humidity within the chamber by using a humidity control means comprising:
• a saturated salt solution disposed within the reservoir;
• and
• means for controlling relative rates of diffusion of water vapor into and out of the chamber, wherein the means provides a rate of water vapor diffusion from the chamber to the outside environment that is less than a rate of water vapor diffusion from the reservoir to the chamber when the relative humidity of the air in the outside environment is lower than the relative humidity of the air in the chamber, and wherein said control means provides a rate of water vapor diffusion from the chamber to the outside environment that is greater than a rate of water vapor diffusion from the reservoir to the chamber when the relative humidity of air in the outside environment is greater than the relative humidity of air in the chamber;
• and
• restricting the movement of solid and liquid matter from the humidity control means to the chamber.

A device for providing controlled air quality characteristics comprising:

• an internal chamber disposed within the device and in air-flow communication with an outside environment through one or more air openings in the device;
• a reservoir disposed within the device separated from the chamber, wherein the reservoir is positioned in air-flow communication with the chamber;
• a salt and water solution disposed within the reservoir for controlling the relative humidity of air within the chamber;
• a hydrophobic membrane interposed between the salt and water solution and the chamber that provides controlled relative rates of diffusion of water vapor into and out of the chamber, and that restricts the movement of liquid or solid matter between the salt and water solution and the chamber;
• and
• a getter disposed within the device and positioned within the device air flow path upstream of the chamber for removing unwanted airborne contaminants.

A sensing system comprising a regulated sensor environment comprising:

• a housing having one or more air openings to an outside environment, and comprising:
• a chamber disposed within the housing in air-flow communication with air routed into the housing from the outside environment;
• a reservoir separated from the chamber that is in air-flow communication with air within the chamber;
• means disposed in the reservoir for controlling the relative humidity of air within the chamber;
• a gas permeable membrane interposed between the chamber and the means for controlling, the membrane providing controlled relative rates of diffusion of water vapor into and out of the chamber;
• and
• means disposed within the chamber for sensing the presence of a predetermined airborne contaminant by change in optical characteristics.

A device for controlling the relative humidity within an air space defined within the device, the device comprising:

• a housing having an outside wall surface and one or more air passages disposed therethrough for receiving air from an environment outside of the housing;
• a reservoir disposed within the housing;
• a chamber disposed within the housing separate from the reservoir and defining an air space within the housing, the chamber being in air-flow communication with the reservoir and air received from the one or more air passages;
• a saturated salt solution and solid salt disposed within the reservoir for controlling the relative humidity of air within the chamber;
• a gas permeable membrane disposed within the housing and interposed between the saturated salt solution and solid salt and the chamber, the membrane providing controlled relative rates of water vapor diffusion into and out of the chamber;
• and
• means disposed within the housing within an air flow path upstream of the chamber for preventing the passage of predetermined airborne contaminants to the chamber.

A sensor system having a relative humidity controlled sensor environment comprising:

• a housing having an outside wall surface and one or more air passages disposed therethrough for receiving air into the housing from an outside environment;
• a reservoir disposed within the housing;
• a chamber disposed within the housing separate from the reservoir and defining an air space within the housing, the chamber being in air-flow communication with the reservoir and with air received into the housing from the one or more passages;
• a saturated salt solution disposed within the reservoir for controlling the relative humidity of air in the chamber;
• a gas permeable membrane disposed within the housing and interposed between the saturated salt solution and the chamber, the membrane providing controlled rates of diffusion of water vapor into and out of the chamber;
• one or more optically responsive sensors disposed within the chamber;
• a photon emitting source disposed within the housing and positioned to emit photons onto the one or more sensors;
• and
• a photon detecting device disposed within the housing and positioned to collect photons emitted onto the one or more sensors.

A humidity controlled sensor system for detecting the presence of a target gas comprising:

• a housing comprising a humidity controlled air space therein, the housing including one or more air passages for placing the air space in communication with air within an outside environment;
• a reservoir disposed within the housing separate from and in air-flow communication with the air space, the reservoir comprising a saturated salt solution for providing a controlled relative humidity environment in the air space;
• a permeable membrane interposed between the saturated salt solution and the air space for providing controlled rates of diffusion of water vapor into and out of the air space, and to prevent migration of liquid and solid material into the air space;
• a getter disposed within the housing and positioned within an air stream running from the one or more air passages to the air space, wherein the getter is adapted to remove one or more predetermined airborne contaminate from air within the housing before reaching the air space;
• one or more optically responsive sensors disposed within the housing and in air-flow communication with air in the air space;
• a light emitting diode disposed within the housing adjacent the one or more sensors for emitting photons onto the one or more sensors;
• and
• a photodetector disposed within the housing adjacent the one or more sensors for receiving photons from the one or more sensors.