Study on Ultrasonic Response to Mechanical Structure of Coal under Loading and Unloading Condition

Figure 1

Schematic diagram for ultrasonic testing of coal samples. 1: compression testing machine, 2: support block, 3: sample, 4: ultrasonic transducer, 5: shielding system, 6: AE receiving probe, 7: preamplifiers, 8: loading control system, 9: ultrasonic signals emission and acquisition system, and 10: electromagnetic shielding room.