Abstract: An air quality sensor includes a detector element array, a processor operatively connected to the detector element array, and a memory. The memory is disposed in communication with the processor and has instructions recorded on the memory that, when read by the processor, cause the processor to execute certain operations including measuring electrical resistance of one of more detector element of the detector element array. A difference is calculated between the measured resistance and a reference resistance, and a determination is made of presence or absence of a contaminant in air communicated to the detector element array from an atmosphere of an aircraft cabin based on the difference between the measured resistance and the reference resistance. Aircraft and methods of monitoring air quality also described.

Abstract: An air quality sensor includes a detector element array, a processor operatively connected to the detector element array, and a memory. The memory is disposed in communication with the processor and has instructions recorded on the memory that, when read by the processor, cause the processor to execute certain operations including measuring electrical resistance of one of more detector element of the detector element array. A difference is calculated between the measured resistance and a reference resistance, and a determination is made of presence or absence of a contaminant in air communicated to the detector element array from an atmosphere of an aircraft cabin based on the difference between the measured resistance and the reference resistance. Aircraft and methods of monitoring air quality also described.

Abstract: A system has at least one sensor and a control for analyzing a signal from the sensor. The sensor is operable to send a signal indicative of a presence of a particular occurrence to the control. The sensor also sends a background signal even without the presence of the particular occurrence. The control evaluates the background signal to identify a need for calibration. A method is also disclosed.

Abstract: A system has at least one sensor and a control for analyzing a signal from the sensor. The sensor is operable to send a signal indicative of a presence of a particular occurrence to the control. The sensor also sends a background signal even without the presence of the particular occurrence. The control evaluates the background signal to identify a need for calibration. A method is also disclosed.

Abstract: A circulation heater is provided which uses a cast body, having resistance heating elements therein and also having spirally wound Teflon tubing wrapped about the heater body. The heater body is formed of cast aluminum or other suitable cast material and after casting is machined to form at least one spiral channel for receiving the heater tube therein. The heater tube is pressed into the tubing channel as the heater tube is progressively wound spirally about the heater body. The channel is formed with an undercut profile wherein the channel is undercut to form a narrower mouth which allows the heater tube to be compressed and then snapped into the channel. The profile of this channel insures direct contact between the tubing and the channel wall over greater than 180 degrees or more than one half of the tube circumference to increase the area of surface contact between the heater tube and channel surface.

Abstract: A sampling device for a substance detection instrument includes a membrane comprising a porous support having a coating thereon, the coating comprising a carborane polysiloxane or an arylene polysiloxane, the membrane having a front side configured to be placed in contact with a test sample and a back side; a sample line having an inlet proximate to the back side of the membrane and an outlet in fluid communication with a substance detector; and a source of carrier gas in fluid communication with the back side of the membrane and the sample line inlet.

Abstract: A circulation heater is provided which uses a cast body, having resistance heating elements therein and also having spirally wound Teflon tubing wrapped about the heater body. The heater body is formed of cast aluminum or other suitable cast material and after casting is machined to form at least one spiral channel for receiving the heater tube therein. The heater tube is pressed into the tubing channel as the heater tube is progressively wound spirally about the heater body. The channel is formed with an undercut profile wherein the channel is undercut to form a narrower mouth which allows the heater tube to be compressed and then snapped into the channel. The profile of this channel insures direct contact between the tubing and the channel wall over greater than 180 degrees or more than one half of the tube circumference to increase the area of surface contact between the heater tube and channel surface.

Abstract: A sampling device for a substance detection instrument includes a membrane comprising a porous support having a coating thereon, the coating comprising a carborane polysiloxane or an arylene polysiloxane, the membrane having a front side configured to be placed in contact with a test sample and a back side; a sample line having an inlet proximate to the back side of the membrane and an outlet in fluid communication with a substance detector; and a source of carrier gas in fluid communication with the back side of the membrane and the sample line inlet.

Abstract: A carbon monoxide sensor includes a housing providing an analyte inlet. Multiple electrodes are arranged in the housing and include a sensing electrode in communication with the analyte inlet. The sensing electrode includes a catalytic material niobium that is configured to oxidize carbon monoxide. Output elements are connected to the electrodes and are configured to provide a carbon monoxide signal in response to an analyte reacting with the sensing electrode.