The YKB-02 Duct Smoke Detector is designed to detect the presence of smoke in the air stream of the sections of the ducts or ventilation compartments by means of the smoke detector mounted on it. Depending on the type of mounted fire detector, the duct smoke detector is produced in two variants: for conventional fire alarm systems (YKB-02K) and for addressable fire alarm systems (YKB-02A). An optical smoke fire detector type FD8030 for conventional systems or FD7130 for addressable systems is mounted on the device. To monitor the status of the integrated fire detector, an external RI31 remote LED indicator is mounted on the duct smoke detector housing. In the event of smoke in the main air duct, some of this smoke passes through the duct smoke detector and activates the fire detector. The latter sends a signal to the fire control panel and the remote indicator outside.