|
Acoustic impedance - Wikipedia, the free encyclopedia (301 words) |
 | The acoustic impedance Z (or sound impedance) is the ratio of sound pressure p to particle velocity v in a medium or acoustic component. |
| Z can be either measured in its consituient units (pressure per velocity) or in rayls. |
| The acoustic impedance Z of an acoustic component (in Pa·s/m) is the ratio of sound pressure p to particle velocity v at a transition with a previous component: |
| Borehole Geophysics and Petrophysics - Acoustic logging (1336 words) |
| In acoustic logging, a transmitter located in the borehole emits a pulse of mechanical energy which is recorded by one or more receivers located in the borehole some distance away from the transmitter. |
| The compressional wave amplitude is used to determine the presence of cement grout behind steel casing and to assess the degree of bonding to the casing and the formation, in 'the cement bond log'. |
| In addition to the head waves, other modes of acoustic energy are present in the full waveform that arise because acoustic energy that is incident on the borehole wall at angles greater than the critical angle is completely reflected back into the borehole (ie, the borehole acts as a waveguide). |
Feeds |
Contact