Acoustic Velocity Transducers

Product Code : GDSAV

Systems to measure the P- and S- Wave velocities within a sample. AV sensors are generally used where pressures and load exceed those where bender elements can be used.

AV sensors are based on the same principle as bender elements but the piezo ceramic elements are not exposed to the environment so they can be used at pressures up to 100MPa and loads up to 2MN. Sensors and sources are mounted in the pedestal and topcap or to the sides of the sample in some cases. Each sensor package contains a Compressional wave (P-Wave) element and two shear wave (S-Wave) elements. The Shear wave elements are set in orthogonal directions to allow two shear waves to be generated with different polarisation. This is important where samples may be cross-anisotropic or even fully anisotropic. 

Applications:

        

Key features Benefits to the user
Multiple Wave types as standard:  Standard sensor package has: P-Wave, S- Wave Polarity 1 & S-Wave Polarity 2.
High speed data acquisition to yield high resolution results: Result accuracy is dependent on the resolution of time in acquired data. Higher speed data acquisition yields higher resolution results.
High Bit count: Yields a more dynamic capture of acquired waveforms with less tuning needed.
Designed to fit most GDS high pressure triaxial and Hoek Cells:
Some existing GDS high pressure cells can be adapted to include GDSAV transducer sets.  Please consult GDS for further information.
Vertical and horizontally mounted elements are available in some cells: Allows users to describe fully anisotropic samples by measuring velocities in all directions and polarities. 
Software controlled switching:
Once the system is set up sensors do not have to be plugged and unplugged to use different wave types.
Axial Load

Up to 2MN

Data Acquisition

16 Bit (Typically 12/14 at high logging rates)

Pressure Range (MPa)

Up to 100MPa

Sample Sizes

38mm, 50mm options available upon request

Weight Approx (kg)

Sample set 3.3 kg, Pedestal 0.95 kg & Top Cap 1.4 kg

Upgrade Options:

Horizontally mounted elements can be added to some cells.