| 摘要 |
PURPOSE:To make it possible to perform accurate, highly reproducible, objective measurement by detecting vibration obtained by hitting a rock bed, transducing the vibration into an electric signal, and analyzing the frequency of the signal. CONSTITUTION:A rock bed to be measured is hit with a rock hammer 1. The generated vibration is detected with a piezoelectric element 2, and a vibration signal is outputted. Said signal is amplified to a specified level in a preamplifier 3. The signal is converted into a digital signal in an A/D converter circuit 4. The signal is stored in a memory 5. The signals are sequentially read out with a FET processor and undergoes Fourier transformation. The frequency spectrum distribution characteristic is obtained. The property of the rock bed is measured, and the results are classified. The results are displayed as graphics or with character symbols on a liquid crystal display 7. Since the element 2 is provided in the hammer 1, the generated vibration can be directly detected, and the effect of surrounding noises is hard to receive. |
