Abstract: An integrated system platform includes a sensor containing an embedded microcontroller and associated circuitry for providing safety critical functionality. Signal conditioning circuitry is coupled to the sensor along with gas concentration determining circuitry, alarm status circuitry and fault status evaluation circuitry. Wherein the sensor is operational with a main control module and at least one alarm output device.

Abstract: An electrochemical gas sensor having an electrode with a catalyst distributed on a porous surface is described. The porous surface can be a polytetrafluoroethylene tape. Alternate embodiments include layered or stacked electrodes.

Abstract: An electrochemical oxygen sensor is provided. The electrochemical sensor includes a housing having first and second compartments, a sensing electrode disposed within the first compartment of the housing, a consumable anode disposed within the second compartment of the housing, a porous separator between the sensing electrode and consumable electrode that separates the first and second compartments and an electrolyte saturating the porous separator and consumable anode. A first aperture on a first end of the housing extends between an outside surface of the housing and first compartment that allows gas access to the sensing electrode. A venting system on a second, opposing end of the housing includes a second aperture extending between the outside surface of the housing and second compartment and has a predetermined permeability that controls pressure in the second compartment and loss of moisture from the sensor.

Abstract: A lead-free, self-corrosion-free electrochemical galvanic oxygen sensor is provided. The preferred sensor includes a container, the container including a lead-free anode, an alkali electrolyte, a carbon platinized with platinum cathode and a nickel wire current collector, wherein the container further includes a diffusion barrier that causes the sensor to operate in the limiting current region.

Abstract: A gas sensor is disclosed. The gas sensor includes a gas sensing electrode and a counter electrode disposed within a housing, and respective conductors that connects the gas sensing electrode and the counter electrode to a sensing circuit. The housing includes walls defining a cavity containing electrolyte in fluid communication with the gas sensing electrode and counter electrode and wherein the walls further comprise one or more coatings or second layers superimposed on the walls. The one or more coatings or second layers have a lower water vapor transport rate than that of the walls, such that, in use, water vapor transport between the electrolyte and atmosphere through the walls of the housing is reduced.

Abstract: Devices and methods are disclosed that can adjust a hydration level in an electrochemical sensor or an instrument which includes such a sensor. The device can include a chamber which can, at least in part, surround an inflow port of the sensor. An adjacent reservoir of water can provide a source of water vapor which can be infused into the sensor.

Abstract: A portable, relatively low power gas detector incorporates a single pellistor-type sensor for sensing an explosive gas of interest. Outputs from the sensor are corrected in accordance with ambient temperature and humidity and pre-stored correction factors based on characteristics exhibited by a plurality of similar sensors.

Abstract: A method and apparatus are provided for setting up a fire alarm system. The method includes the steps of coupling a user interface to a wireless fire detection system having a wireless gateway and a plurality of wireless fire detectors, receiving a selection through the user interface of a wireless transmission parameter used in transmitting messages between the wireless gateway and the plurality of wireless fire detectors, determining a latency time value associated with use of the received selection of the wireless transmission parameter in the transmission of messages between the wireless gateway and the plurality of fire detectors, displaying the calculated latency time value on the user interface and changing an operating mode of the plurality of wireless fire detection devices in accordance with the received selection.

Abstract: A compensated gas detector incorporates first and second pellistors combined with first and second resistors and an intervening switch. Control circuits can close the switch for normal gas detection. The switch can be opened to carry out diagnostic measurements. A compensation coefficient can be established in order to compensate outs from the pellistors due to mechanical damage thereto.

Abstract: A gas sensor includes a substrate having a low thermal conductivity. Localized heating can be produced using a serpentined heater carried by the substrate. The low thermal conductivity of the substrate substantially confines the generated heat to a region local to the heater thereby reducing required power to operate the sensor. Multiple sensing elements can be deposited onto the substrate adjacent to respective heaters and relatively close together because of the thermal isolation provided by the substrate. In one embodiment, the sensor can include the ceramic substrate, the heater, catalytic material overlying the heater with a gas impermeable layer overlying, at least in part the catalytic material.

Abstract: A gas sensor includes known types of electrodes such as sensing electrodes, counter electrodes or reference electrodes to sense the presence of a predetermined gas. In addition, at least one diagnostic electrode is carried in the sensor. The diagnostic electrode implements at least one diagnostic function without substantially impairing the gas sensing function. The diagnostic electrode is immersed in sensor electrolyte.

Abstract: An electrochemical gas sensor includes additional gas diffusion electrodes incorporated to carry out one or more diagnostic functions while the sensor is responding to a target gas. Members of a plurality of sensing and diagnostic electrodes can be switched by associated control circuits to intermittently sense a target gas while others intermittently sense a different gas. The diagnostic electrodes are in direct communication with the target gas that is entering the cell.

Abstract: A compensated gas detector incorporates first and second pellistors combined with first and second resistors and an intervening switch. Control circuits can close the switch for normal gas detection. The switch can be opened to carry out diagnostic measurements. A compensation coefficient can be established in order to compensate outs from the pellistors due to mechanical damage thereto.

Abstract: A method of operating an electrochemical gas sensor includes: a) exposing, for a first predetermined duration, the electrochemical gas sensor to an atmosphere containing a target gas while the gas reaction capability of the electrode assembly is substantially reduced from a working level, such that target gas is collected within the housing; b) increasing the gas reaction capability of the electrode assembly to a level at which it consumes collected target gas and thereby outputs a signal to the sensing circuit, including an initial transient decay signal; c) monitoring the transient decay signal; and d) analysing the rate of decay of the transient decay signal to determine whether the performance of at least one component of the electrochemical gas sensor is within acceptable limits. An apparatus for operating an electrochemical gas sensor, adapted for connection to an electrochemical gas sensor via a sensing circuit for control thereof, can carry out the disclosed method(s).

Abstract: A gas detector includes at least two electrodes. The electrodes are carried on a common substrate having first and second spaced apart surfaces. The electrodes are formed on respective ones of the surfaces with the substrate sandwiched therebetween.

Abstract: A gas sensor is disclosed. The gas sensor includes a gas sensing electrode and a counter electrode disposed within a housing, and respective conductors that connects the gas sensing electrode and the counter electrode to a sensing circuit. The housing includes walls defining a cavity containing electrolyte in fluid communication with the gas sensing electrode and counter electrode and wherein the walls further comprise one or more coatings or second layers superimposed on the walls. The one or more coatings or second layers have a lower water vapor transport rate than that of the walls, such that, in use, water vapor transport between the electrolyte and atmosphere through the walls of the housing is reduced.

Abstract: An electrochemical oxygen sensor is provided. The electrochemical sensor includes a housing having first and second compartments, a sensing electrode disposed within the first compartment of the housing, a consumable anode disposed within the second compartment of the housing, a porous separator between the sensing electrode and consumable electrode that separates the first and second compartments and an electrolyte saturating the porous separator and consumable anode. A first aperture on a first end of the housing extends between an outside surface of the housing and first compartment that allows gas access to the sensing electrode. A venting system on a second, opposing end of the housing includes a second aperture extending between the outside surface of the housing and second compartment and has a predetermined permeability that controls pressure in the second compartment and loss of moisture from the sensor.

Abstract: An electrochemical sensor includes a micro-porous plastic membrane supported on a disk and located between a gas inflow port and an electrolyte having a gelled oxygen diffusion barrier. The oxygen diffusion barrier, formed of gelled agar, minimizes thermal shock effects by impregnating any porous materials in the sensor.

Abstract: The present invention provides a colorimetric gas detector comprising a substrate bearing a material that can react with a gas in an atmosphere being monitored and wherein the reaction causes the material to change the radiation at which the material absorbs or radiates radiation (the color-change material). The material is located in at least one discrete area of the substrate. By providing the color change material in discrete areas, the amount of such material can be reduced and different types of color-change material can be included on a common substrate to detect two or more gases simultaneously.

Abstract: A docking station for use with gas sensors includes limited test and diagnostic circuitry directed to specific characteristics of selected detectors. Where a family of detectors is to be evaluated, a universal interface for that family can be included. A single port can be used for multiple different detectors irrespective of specific detector characteristics.