| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an optical pendulum seismic sensor as a protection-against- disasters alarm device and a protection-against-disasters alarm judgment method, using the sensor, in which a pendulum motion containing a miscelleneous tremor, large-scale seismic waves and small-scale faint seismic waves are discriminated and detected without being subjected to the influence of a noise, in which a malfunction is small, whose performance is stable, whose sensitivity is high and which are low-cost. SOLUTION: An optical-miscelleneous-tremor removal means by which only seismic waves are extracted from miscelleneous vibrations detected by a sensor is built in a seismic sensor which optically detects a pendulum motion. The optical-miscelleneous-tremor removal means is composed of the intensity distribution of light, a magnitude relationship and a geometrical arrangement which are formed by the arrangement constitution of an optical component such as a perforated plate 4 or the like which gives a light intensity distribution to light from a light source 1.</p> |
