Patent ID: 7825817

Claim:
A sensor and alarm system for a building comprising: a power supply module having a permanent disconnectable connection to power of the building; a power interrupt switch that momentarily interrupts the permanent connection to power of the building, and then provides a power-on sequence of indicators in a pre-determined pattern to exhibit a satisfactory condition or a diagnostic meaning; a sensor module connected to the power supply module; and an alarm module connected to the sensor module; and wherein: the sensor module comprises: an interface circuit; a processor connected to the interface circuit; a sensing element connected to the interface circuit; the alarm module comprises: a visual indicator; and an audio indicator; the sensing element senses a gas in the building; and the alarm module activates the visual and/or audio indicator of a gas sensed in the building and of a level of concentration of the gas; wherein the processor has an output that initiates the power-on sequence of visual and audio indicators in the pre-determined pattern that tests the connection and operation of the system, wherein an expected pattern of visual and audio indicators indicates a correct connection and/or operation and an unexpected pattern indicates an incorrect connection and/or operation.