Battery Operated Smoke Detector
An EI Electronics smoke detector, featuring an Ionisation sensor which enables it to react particularly effectively to fast flaming fires. A loud alarm featuring a test button to enable regular checks. Battery operated for protection even in the event of a power cut. Ionisation smoke detector operate on the principle that electrical current flowing between electrodes in an ionisation chamber is reduced when smoke particles enter. Battery included. Loud alarm 85decibels at 3 metres. No wiring required. Requires 1x 9V battery, included. Always read instructions.
A smoke detector is a device that senses smoke, typically as an indicator of fire. Commercial security devices issue a signal to a fire alarm control panel as part of a fire alarm system, while household smoke detectors, also known as smoke alarms, generally issue a local audible or visual from the detector itself.
Smoke detectors are housed in plastic enclosures, typically shaped like a disk about 150 millimetres (6 in) in diameter and 25 millimetres (1 in) thick, but shape and size vary. Smoke can be detected either optically or by physical process, detectors may use either, or both, methods. Sensitive alarms can be used to detect, and thus deter, smoking in areas where it is banned. Smoke detectors in large commercial, industrial, and residential buildings are usually powered by a central fire alarm system, which is powered by the building power with a battery backup. Domestic smoke detectors range from individual battery-powered units, to several interlinked mains-powered units with battery backup; if any unit detects smoke, all trigger even in the absence of electricity.