| 摘要 |
A fire sensor discriminates between fires and the flash caused by a projectile piercing the wall of a protected area. The sensor system comprises first and second radiant energy detectors, each sensitive to radiation within different spectral bands. Each detector is coupled to a control signal means for generating a control signal when the radiation sensed exceeds a predetermined amplitude. A third control signal means is responsive to the first and second detectors, and is operative to generate a third control signal whenever the ratio of the amplitude of the energy sensed by the first detector to the amplitude of the energy sensed by the second detector is less than a predetermined value; not generate the third control signal whenever the ratio of amplitudes exceeds the predetermined value; and delay generation of the third control signal for a predetermined period of time after the ratio of amplitudes falls below the predetermined value. An output control signal is then generated only if all three control signals are simultaneously generated. The decay of the flash radiation is thereby electrically simulated, allowing the fire sensor to sense whether a fire develops after the flash passes. |
