| 摘要 |
A combined detector and sounder device for a fire alarm system comprises a base 10 which houses a PCB 12 and a sounder device 16, and a removable dome-shaped head 11 which houses an optical smoke sensing chamber 33. A temperature sensor 15 mounted to the PCB 12 extends into an airway 32 between the sensing chamber 33 and the body 10. Electrical smoke sensing components e.g. LED 17 and a phototransistor extend from the PCB 12 through the airway 32 into the smoke sensing chamber 33. The arrangement of all of the electrical components on the base means that the sensing chamber 33 can be opened for cleaning the optical components without the need disconnect electrical connections between the removable head 11 and the base 10. |
