Abstract: A system for monitoring the operability of fire event sensors having a programmable logic circuit which automatically and continuously analyzes whether readings obtained from fire event sensors satisfy multiple predetermined parameters. Parameters defining operability may include the mere receipt of a signal from a sensor, elapsed time between a request for data by the circuit and receipt of said data, substantive quality of signals, sensor sensitivity, strength of power source, or other parameters. The parameters are modifiable to facilitate many different types of sensors without the addition of any additional circuitry. The system also monitors operability of the self-checking routine itself as well as checking the circuitry of a fire detection unit and strength of power source.

Abstract: A system for monitoring the operability of fire event sensors having a programmable logic circuit which automatically and continuously analyzes whether readings obtained from fire event sensors satisfy multiple predetermined parameters. Parameters defining operability may include the mere receipt of a signal from a sensor, elapsed time between signals, substantive quality of signals, sensor sensitivity, strength of power source, or other parameters. The parameters are modifiable to facilitate many different types of sensors without the addition of any additional circuitry. The system also includes manual testing of the self-checking routine itself as well as checking the circuitry of a fire detection unit and strength of power source. Means for resetting the system is also provided.

Abstract: An alarm for sensing different conditions of an ambient air presents a housing for an alarm circuit, the housing having lobes for first, second and third circuit sensors surrounding a single circuit alarm. The alarm circuit delivers the current to a logic chip which produces a current for sounding the alarm in different patterns according to the sensed air condition. The configuration of the housing depends the alarm below the housing proper so as not to interfere with the alarm sound. The housing allows the installation of three air condition sensors at one selected location.