The capabilities of the Berkeley Rock Laboratory, under the directorship of Professor Steven D. Glaser, include several high-speed data acquisition systems, a computer-controlled ultrasonic system, network analysis capabilities, sensor fabrication facilities, and load-testing facilities.  A multi-channel 24 bit digital analyzer belonging to Prof. Morrison will be used for the ERT data acquisition.  The 3-D resistivity modeling codes are also readily in place at Morrison’s laboratory facility.

Polyaxial Loading Frame: custom-built for the UC Rock Laboratory by TerraTek in 1995.   The device can apply up to 50 MPa loads on a rectangular specimen (460 mm x 300 mm x 300 mm), on 3 independant axes using flat-jacks as the loading mechanism.  This machine would have certain advantages for investigating effects of stress anisotropy, and because it is self-contained is easier to safely maintain the required temperatures.  A new digital-based test control system incorporating 4 indepenent digital PID loops, each updated at 300 ms intervals, and 16 independent channels of 140 dB CMR signal conditioning, will be used to control the test.  The other testing device is an ultra-stiff 1 million pound MTS 207.70 load frame.  The frame has an axial stiffness of > 6x10⁸ lb/inch, allowing accurate measurement of post-peak behaviors of brittle materials.  The frame and 20,000 psi pressure vessel has just been refurbished, and is integrated into our digital control system.

Custom Data Acquisition System:  twenty 12-bit and four 14-bit high-speed data channels

Each digitizer channel is controlled by its own CPU which oversees memory management, triggering, and data storage to disk.  This results in virtually continuous logging to disk. 

• data streaming directly to disk (10 Msamples/s per channel)

• continuous waveform time-stamping with an accuracy of up to  
    plus/minus 50 ns.

• four-channel full and/and/or logic trigger modes

• user configurable timed trigger windows

• trigger rearming within 25 of microseconds

Active Imaging System: 50 kHz to 5 MHz frequency range (Ritec RAM-10000)

• 800 V gated amplifier

• two phase-sensitive receiver channels in quadrature

• arbitrary wavelets generated by a PC-mounted arbitrary 
    waveform generator

Switching Matrix: 32-Channel custom, Cytec Inc.

• double-layer switching, 160 dB isolation between 800 V source 
    and mV received signals

• fully computer-controlled

• 32 sensor fully stacked sender/receiver scan in 2 seconds

Computers: Silicon Graphics workstation and four Linux workstations

Material Testing System

• Stiff MTS 4.6 MN load frame

• 10.5x10⁹ N/m spring rate

• 500 kN large-opening load frame

• 4 loop computer-controlled servo-hydraulic servo control

Fabrication: The Berkeley Rock Lab has a full sensor fabrication facility where the ‘Glaser’ high-fidelity acoustic emission sensors (embeddable and non-embeddable) are constructed, and sensor design improvements evaluated.  Fabrication facilities include a hot-air soldering station, vacuum ovens, machine tools, and specialized hand tools. Calibration facilities include 2 NIST calibrated reference transducers, and an H-P 4192A network analyzer which allows complete quantification of one- and two-port systems.