Adaptation of the S-5-S pendulum seismometer for measurement of rotational ground motion

Autor: Jaromír Knejzlík, Zdeněk Kaláb, Zdeněk Rambouský
Rok vydání: 2012
Předmět:
Zdroj: Journal of Seismology. 16:649-656
ISSN: 1573-157X
1383-4649
DOI: 10.1007/s10950-012-9279-6
Popis: The Russian electrodynamic seismometer model S-5-S has been adapted for the measurement of rotational ground motion. The mechanical system of the original S-5-S seismometer consists of electrodynamic sensing and damping transducer coils mounted on an asymmetrical double-arm pendulum. This pendulum is suspended on a footing using two pairs of crossed flat springs, which operate as the axis of rotation. The pendulum is stabilised by an additional spring. The S-5-S can be used either as a vertical or as a horizontal sensor. The adaptation of the S-5-S seismometer described below involves removal of the additional spring and installation of an additional mass on the damping arm. Strain gauge angle sensors are installed on one pair of the crossed flat springs. The main dynamic parameters of the rotational seismometer created in this way, i.e. the natural period and damping, are controlled electronically by feedback currents proportional to the angular displacement and angular velocity, both fed to the damping transducer coil. This new seismometer, named the S-5-SR, enables measurement of the rotational component of ground motion around the horizontal or the vertical axes. The output signal from this S-5-SR seismometer can be proportional either to rotational displacement or rotational velocity.
Databáze: OpenAIRE