Abstract
To record long period seismological movements, we proposed in the previous paper a new instrument as a precise seismometer with a dynamic long period pendulum using gyroscope and examined the various dynamical characteristics of the system subject to horizontal seismic movements.
In this paper, we consider the observation system to record the vertical component of seismic movements. In this system, we utilize a quasi-TDF gyroscope (transducer) in addition to an ordinary mass-spring system. The vertical seismological movement transferred to the torque causes the gyro-axis to precess about the perpendicular axis, and the output signal (angular displacement or velocity) is measured by a measuring instrument.
Topics in this paper are summarized as follows: 1) We analyze dynamical equations of a transducer theoretically when seismic accelerations are applied to it. And we examine the various dynamical characteristics as a seismometer. 2) We present the procedure for designing this system for practical use and provide numerical examples. 3) A digital simulation for the system is carried out and satisfactory results are obtained. 4) We present technical considerations for future development.
