Experimental Procedure

図 2: Experimental setup

1. Set-up equipment according to Figure 2.

2. Record the length of the rock sample using the calipers.

3. On the Pulse Generator, set the:

   a.

   Pulse delay to $0.1\,\mu$s

   b.

   Voltage output (amplitude) to 10V

   c.

   Pulse width to $1.0\,\mu$s

   d.

   Frequency to 100 Hz

   e.

   Switch to P wave

4. Take an initial reading of P waves without the sample in the sample holder. Ensure that the sample holder is under a pressure of 500 psi, which is approximately equal to 5 mV. In the view screen of the oscilloscope, use the cursor to determine the time it takes for the acoustic pulse to register the first maximum or minimum wave (Figure 3). The time for the initial reading with no sample will be subtracted from the readings with the sample in place.
   

5. Place sample into sample holder and take five P wave readings. Be sure to subtract the initial reading.

6. Switch the Pulse Generator to S wave, repeat steps 4 and 5.