... circuit 4.Infrared scatters on surface of smoke when smoke enters darkroom of detector 5.Photoelectric ... EN14604 smoke alarm, UL smoke detector, NF smoke alarm, optical smoke alarm, 9V battery operated smoke detector, 9V smoke alarm,EN50291 ... light,wireless detector, radio link smoke alarm, hardwired smoke alarm, conventional smoke detector, addressable smoke detector, addressable fire alarm systems ...