... reflect back, and received by high sensitivity geophone (seismic detector, seismograph, seismometer). Data processing, by means of energy- ... the problem when working in the small place of the mine tunnel. Technical Parameters1. Batter highest open circuit voltage: ... ≤600ms13. Preamp gain: 40dB.We are leader in china. Mine intrinsically safe type seismograph, seismometer, geophone, seismic detector