Pilot sensors for rotation strong motion recording

Kozák, J., J. Buben, P. Jedlička and J. Knejzlík

Within the running Czech-USA AMVIS Grant on "Fluidal Seismo" sensor, several variants of rotation seismographs were designed, built and preliminarily tested:
a)Pendulum with rotation axis made of flat crest springs. For dis-placement-voltage conversion an electro-magnetic convertor was used,
b)Solid-state disc bob fixed on a spindle imbeded in bearings, equiped with capacity or electromagnetic transducer,
c)Fluidal inertial mass in a ring-shaped tube equiped with i)elec-tromagnetic, ii)tensometric, iii)pressure-voltage transducer.

Preliminary results obtained during field and laboratory testing of the above sensors are presented and discussed.