| 摘要 |
PURPOSE:To make possible high precision detection by using a linear pressure- sensitive element as an oscillation pressure-sensing means for an oscillation sensor using the inertia of a weight. CONSTITUTION:It is so constituted that a weight 2 is supported from two directions on a -shaped support frame 1 fixed on a ground through linear piezoelectric elements 3a, 3b whose both ends are supported. The linear piezoelectric elements 3a, 3b have an internal electrode and a surfacial electrode respectively inside and outside of a tubular piezoelectric element. These electrodes are connected to an electric signal detection circuit. An internal electrode 6, a surfacial electrode 6a, a preamplifier 7, a band pass filter 8, an amplifier and an antidisaster actuation circuit 10 are provided as seen in an enlarged chart for the end of a linear piezoelectric element 3. The band pass filter 8 has a seismic frequency of 1-10Hz, so that it passes only signals of this frequency band. Thus the antidisaster actuation circuit 10 closes a main stopper for a city gas pipe, etc. or shuts off a power supply. |
