Improvements in and relating to smoke detectors

摘要

A smoke detector 1, is formed of two or more units; the first unit 3 has a sub unit 13, 15 and a base 4 latched together; the first unit is adapted to be permanently fixed to a surface such as a ceiling; the first unit contains electronic control circuitry 7 to process a signal from one or more sensors 57 in the detector: a second unit 5 which has a smoke chamber 17 is detachable from the first unit so that the smoke chamber and or any other parts affected by smoke can be detached from the fixed parts including the electronic circuitry for cleaning or replacement with clean parts.