Equipment for Drilling, Measurement of Sound, and Physico-mechanical Properties of Rocks

The instrument used for sound measurement in this work was Spark 706 from Larson Davis, Inc., Depew, New York (Figure 5.2). The instrument was equipped with a detachable 10.6-mm microphone and 7.6-cm cylindrical mast type preamplifier. The microphone and preamplifier assembly were

Acoustic Calibrator was used for calibrating the sound level meter. Before taking any measurement, the acoustical sensitivity of the sound level meter was checked using the calibrator.