... vertical and horizontal geophone. CDJ middle & high frequency geophones, 4,10,15,28,30,40,60,80 or 100Hz, are widely ... ±5%Sensitivity G (v/cm/s)0.28±5%0.26±5%0.26±5%0.30±5%0.25±5%Coil Resistance Rc (Ω)500 ... %800±5%1020±5%Damp Bt0.7±10%0.6±10%0.6±10%0.6±10%0.5±10%Harmonic Distortion D (%)≤0.2Insulation Resistance R (MΩ)≥20Coil to ...