Abstract: A security alarm system has a plurality of sensors for fire, smoke, intrusion and appliance operation. A central monitor is provided for monitoring and perceptibly indicating the status of each of the sensors. To provide for communication between the sensors and the central monitoring system, transmitters are located on the sensors and a receiver is provided on the central monitor. When one of the sensors establishes an alarm condition, its transmitter is actuated to transmit information indicating the type of alarm. A portable keyboard loads information data into an electronic memory of each of the transmitters and into the electronic memory associated with the receiver. The keyboard is separable from each memory to preclude altering of the information stored in the electronic memory of the respective transmitter.

Abstract: A tester device is disclosed for a photoelectric smoke detector. The tester, when actuated, increases the intensity of light emitted by a light source to simulate in the sample chamber by such light scattering and reflecting off chamber walls, an amount of light which would be scattered by a predetermined concentration of smoke to which a photoelectric sensor is responsive and causes an indication that the detector is functioning as intended.

Abstract: In an electronic smoke sensing and alarm device, a dual ionization chamber arrangement comprises a single source of radioactive material and first and second chambers separated by a common electrically conductive electrode. A portion of the radioactive material ionizes the air in the first chamber and another portion of the radioactive material ionizes the air in the second chamber. This arrangement provides an accurate control on the current flow through each chamber.

Abstract: An infrared intrusion detector has an optical system for gathering infrared radiation from discrete sensitive regions and focusing such received radiation onto an infrared radiation sensor. The detector includes a monitoring device to sound an alarm when radiation sensed reaches a predetermined level. The optical system comprises an optical collector for gathering radiation from a field which includes the sensitive regions and for converging such radiation onto a plurality of reflectors. Each reflector determines one of the discrete sensitive regions and, in turn, is oriented to reflect converging radiation gathered from a sensitive region on the detector. The invention provides a simple, efficient optic system for a broad field of gathering infrared radiation, concentrating and focusing it in a manner to provide sufficient levels of received radiation for purposes of detection.