Abstract: A method for isolating suites includes the steps of isolating the suites when an alarm is initiated, setting a timer during isolation creating a window of time to clear a short circuit, clearing said short circuit, removing isolation from the suites as the timer reaches completion, determining if there is a short circuit in each of the suites, and isolating suites that have a short circuit.

Abstract: A method and apparatus for activating a fire-alarm pull station. The pull stations includes a non-contact switch located within a housing, a movable actuation device linked to the non-contact switch wherein the device moves between an activation and non-activation position and an actuator protector linked to the non-contact switch to aid in preventing improper activation of the non-contact switch.

Abstract: A device for sensing a dangerous condition includes a sensor that provides a signal when a dangerous condition is sensed by the sensor. A power source is provided which is in communication with the sensor. The power source supplies the sensor with power. A trigger is provided which is in communication with the sensor. The trigger is activated by the signal to prevent the dangerous condition from producing a harmful effect. In one embodiment of the invention the power source is a thermoelectric power supply and the sensor is a self calibrating sensor.

Abstract: An economizer control for controlling air quality. The economizer control includes a sensor that senses characteristics of air, a damper located relative to the sensor so that the damper can control air flow of outside air and re-circulated air to the sensor, and a controller in communication with the sensor and the damper. The controller controls the opening and closing of the damper according to conditions sensed by the sensor.

Abstract: A method of measuring a rate of change of carbon dioxide concentration in recirculated air of an engine, is disclosed. The method includes installing a conductive sample tube into an engine's pre-combustion/air-mixing chamber, and installing a carbon dioxide sensor, remote from the chamber, to measure relative concentrations of carbon dioxide. The method may also be used to measure nitrogen oxide exhaust gas levels.

Abstract: A device for sensing a dangerous condition includes a sensor that provides a signal when a dangerous condition is sensed by the sensor. A power source is provided which is in communication with the sensor. The power source supplies the sensor with power. A trigger is provided which is in communication with the sensor. The trigger is activated by the signal to prevent the dangerous condition from producing a harmful effect. In one embodiment of the invention the power source is a thermoelectric power supply and the sensor is a self calibrating sensor.

Abstract: An automatic calibration mode for a carbon dioxide sensor is based on using a zero gas. The sensor is designed to recognize a distinctive rate of change pattern of carbon dioxide concentrations that would be indicative of a zero calibration routine. This approach can be used for other infrared sensors.

Abstract: A programmable electronic circuit is disclosed. The circuit includes a CPU, signal-generating circuitry, and RC circuitry having at least two capacitors, such that when both of the capacitors are switched into the RC circuitry by the CPU, a signal is produced from an output of the signal-generating circuitry that is longer in duration than when one of the capacitors is switched into the RC circuitry.

Abstract: A method for compensating for baseline or span drift in gas sensing equipment includes obtaining gas concentration data over a time period and identifying a quiescent period within that time period. The method compares a component concentration corresponding to the quiescent period with one or more additional component concentrations relating to different quiescent periods and calculates an estimated background gas concentration for a predetermined number of time periods. The estimated background concentration is then compared to a preset, or expected, background concentration, and a correction value is calculated. For baseline drift, a correction value is determined to be the difference between the estimated background concentration and the present (expected) background concentration. For span drift, a correction value is determined to be the ratio of the estimated background concentration to the preset (expect) background concentration.

Abstract: A single communication apparatus for alarm system control boxes that include the combination of a digital communicator and a remote communicating device. The communicating apparatus transmits status reports and events to a remote location. Remote login is permitted to access the control box through a external port or through the remote communication device.

Abstract: A method for determining the presence of an occupant in an enclosure space, particularly a trunk compartment, based on a rate of change of carbon dioxide concentration in the space/compartment, is disclosed. The primary sources taken into consideration are customary and non-customary leakages of carbon dioxide into the space to be measured. A warning/control logic is preferably configured to identify a rate of change of carbon dioxide that is likely when one or more humans occupy the space/compartment.

Abstract: A diffusion-type NDIR gas analyzer with an improved response time due to convection flow created by a temperature gradient between gas located within a waveguide and gas located within a diffusion pocket of space created between the waveguide and a semi-permeable membrane which surrounds the waveguide. The temperature gradient may be created by a thermally resistive radiation source that is not thermally isolated from the waveguide. The semi-permeable membrane is made of a hydrophobic material and has a thickness sufficient to provide its own structural integrity. The semi-permeable membrane can have a porosity less than approximately 50 &mgr;m and be comprised of ultra high molecular weight polyethylene or TEFLON®.

Abstract: A method for indicating a condition of oxygen depletion in a space, is disclosed. The method of measuring oxygen depletion is employed using the rate of change of carbon dioxide as a surrogate indicator of the amount of oxygen being depleted or displaced in the air. Displacement may be measured when the rate of change of carbon dioxide concentration falls within a rate of change range, or rises above or falls below a rate of change threshold level that indicates the displacement of oxygen.

Abstract: A method for detecting improper venting of a combustion appliance within an interior space relies upon a carbon dioxide detector to determine whether a preselected criterion indicative of improper venting is exceeded. The preselected criterion can be a threshold concentration of carbon dioxide or a threshold level of rate of rise of carbon dioxide concentration that is exceeded at a specified time or over a specified interval of time. The method can be used to detect leaks in a residential furnace, at very low levels, during start up of the furnace by measuring the preselected criterion in a heated air duct.

Abstract: A fire detector is equipped with a smoke detector and electrical circuitry for declaring a fire alarm if a smoke concentration based fire detection criteria is satisfied. A CO.sub.2 detector is included in the fire detector for forming an a priori estimate of the probability of the existence of a fire. If the a priori probability rises above a predetermined level, the smoke concentration base fire detection criteria of the smoke detector are altered to allow the more rapid detection of a fire.