1Hz--100Hz Vertical, Horizontal and 3 Components Geophones. CDJ Series Geophones, natural frequency from 1Hz to 100Hz, include vertical geophone, horizontal geophone, bi-component geophone, tri-component geophone and inner-well geophone.CDJ low-frequency geophones, 1Hz, 2Hz, 2.5Hz or 3Hz, are widely used in deep seismic prospecting, earthquake monitoring, microseismometry in engineering, surface ...