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
![Servo type](/assets/images/support/library/seismograph/seismograph-01/img_servo01.jpg)
Typical principle of electrical systems. Stable output can be obtained from the acceleration of a linear signal.
Seismographs incorporate this element in three axes.
![Servo type](/assets/images/support/library/seismograph/seismograph-01/img_servo02.png)
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. -
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.