The development of a single-component non-cable seismograph in underground coal mines

In-seam wave seismic exploration, featured in wide detection range and high accuracy, plays an increasingly important role in the refined exploration of coal geological structures. However, most seismic exploration equipment is bulky, with a large number of cables are laid in construction, leading to low efficiency and high construction cost. This seriously restricts the development of high-precision in-seam wave seismic exploration technology in underground coal mines. Based on the design concept of nodal seismograph, the moving coil geophone is integrated into a complete cavity with the acquisition and control circuit, the time precision keeping circuit and the power supply circuit. The system is flexible and unconstrained, which solves the problem of multi-channel seismic data acquisition under complex working conditions in underground coal mine. The timing synchronization device is designed, and the timing synchronization between each acquisition unit is solved by the clock mechanism of GPS timing and temperature-complementary crystal oscillator. Then the acquisition system is miniaturized, lightweight and highly integrated. After laboratory and field tests, all the performance indicators meet the design requirements.