JA-111ST Bus combined smoke and heat detector
When the detector is used with inserted batteries (3x 1.5V AA) from which it can be powered, it can continue operating as a stand-alone detector when the 12 V power supply is disconnected (EN 14604).
The detector indicates fire hazard using the built-in LED indicator and acoustic signalling.
The JA-111ST consists of two independent detectors – an optical smoke detector and a heat detector. The optical smoke detector works on the principle of scattered light. It is very sensitive to large dust particles which are present in dense smoke. It is less sensitive to smaller particles generated by the combustion of liquids such as alcohol. That is why the fire detector also contains a built-in heat detector which has a slower reaction but is much better at detecting fire which generates only a small amount of smoke.