Principles of Seismometer Sensors
Principle of Sensor
Sensors are generally classified into two categories; Electric and Mechanical typesAll of IMV’s seismic monitoring systems adopt the electric type sensors.
Electric type
Servo type
Typical principle of electrical systems. Stable output can be obtained from the acceleration of a linear signal.
Seismographs incorporate this element in three axes.
Mechanical type
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Drop ball type
Reaction acceleration values are set by the dimensional ratio of the steel ball and the receiver.
Disadvantages: not yet compatible with direct earthquakes, maximum level not known.
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Pendulum type
Reaction acceleration values are set by the dimensional ratio between the contact and the micrometer.
Disadvantages: uncompliant with direct earthquakes, maximum level not known.