The invention discloses a reflective point type optical-
fiber smoke-sensitive
fire detector. The reflective point type optical-
fiber smoke-sensitive
fire detector comprises a front-end detecting part and a background
processing part, wherein the front-end detecting part comprises a
smoke chamber, a transmitting card frame, a reflecting card frame, a reflecting film, a transmitting optical cable, a receiving optical cable and a hard plastic
pipe; the background
processing part comprises a
light source, a
light source modulator and a
signal detection processor; the
light source is a green-light LED (Light-Emitting
Diode); the transmitting optical cable and the receiving optical cable are communication level plastic optical cables; the transmitting optical cable and the receiving optical cable are arranged in the hard plastic
pipe, and the transmitting card frame is arranged outside the hard plastic
pipe; one end of the transmitting optical cable and one end of the receiving optical cable are level to an opening of the top end of the hard plastic pipe, and the other ends of the transmitting optical cable and the receiving optical cable are respectively connected with the light source and the
signal detection processor; the reflecting film is arranged at the side surface of the reflecting card frame; and the transmitting card frame, the reflecting card frame and the hard plastic pipe are externally covered with the same smoke chamber. The design disclosed by the invention not only avoids using of electronic components and is applicable to places with inflammables and explosives and large
electromagnetic radiation strength, but also can meet the requirement of a fire-fighting alarm product, and is high in sensitivity, simple in structure and low in installation and maintenance cost.