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ABEM - RAS 24


  • Available with 12 or 24 channels
  • 24-Bit Delta-Sigma A/D conversion
  • Wide dynamic range (117db @ 2ms)
  • Connect up to ten boxes (240 chans)
  • 3D on up to ten lines
  • Automated system performance tests
  • Signal enhancement for noise reduction
  • Intuitive operation under Windows 98
  • Operates with any laptop
  • Lightweight - 5 kg
  • Uses standard 12 channel spread cables
    •

    The RAS-24 is a distributed exploration seismograph intended for smaller refraction and reflection surveys where cost, portability and ease of use are essential. The RAS-24 offers 24 channels (12 channels optional) of high performance 24-bit A/D conversion in a small, lightweight package. The advanced RAS-24 system software provides a wide range of features for the most demanding jobs, with the point and click ease of use of Windows. Since the RAS-24 is a distributed system, it can be easily expanded in 24 channel increments up to 240 channels for both 2D and 3D projects. Applications for the RAS-24 include shallow oil, gas and mineral exploration, ground water surveys, site remediation, rippability surveys, fault location, depth-to-bedrock, VSP and tomography and other general geotechnical surveys. Whether you are looking for a refraction seismograph for depth-to-bedrock survey, or a reflection seismograph for shallow oil and gas exploration, the RAS-24 provides the performance and versatility you need to get the job done at a price far below any other system on the market. To download a fully functional version of the RAS-24 system software or to receive a free evaluation copy by mail, please email a request to sales@abem.se.

    Applications    :
    • Oil & Gas Exploration
    • Mineral exploration
    • Geotechnical surveys
    • Engineering geology
    • Groundwater surveys
    • VSP and tomography
    		    
    • Depth-to-bedrock
    • Fault location
    • Site remediation
    • Surface wave analysis
    • Rippability surveys
    • Teaching and Research
     
    Easy to use
    Operating under Windows 95/98, the RAS-24 system software has a familiar point and click interface which is easy to learn and operate. With buttons, scroll bars and single key commands for commonly used functions, the RAS-24 user interface is designed to allow direct access to important system functions.
    And setting up the RAS-24 couldn’t be easier. Select the type of survey you want to perform - refraction, 2D reflection with roll, or 3D - and the RAS-24 configures itself. And when you’re back in the office, you can review the observers log and view, pick and print records on your office system using the same software that you ran in the field.

    Expandable
    Because the RAS-24 is a distributed system, it provides a unique flexibility not found in any other engineering seismograph. Connect one RAS-24 to a laptop and you have a very portable 24-channel (or optionally 12 channels) refraction seismograph. Connect ten units together in a line and you have a 240-channel, 2D reflection seismograph complete with roll. Rearrange those same ten units and you have a ten line, 24 channel/line 3D system. And no special hardware is required for any of these configurations. The system software manages the roll for 2D and the active portion of the spread for 3D operation so no roll switches or CDP cables are required. The ability to add channels to fit the job at hand ensures that RAS-24 will be able to handle all your future exploration requirements.

    Highlights:
    • Expandable in inexpensive 24-channel units. Just add
      another RAS-24 and the system automatically recognizes it.
    • No roll switch for reflection shooting. Roll is controlled
      by the system software.
    • No heavy, expensive CDP cables. Uses 12-channel
      spread cables for all configurations.
    • Integrated 3D operation. The RAS-24 system software manages
      each line as an independent entity.
    • All testing functions are built in and controlled by the operator from the
      laptop using the RAS-24 system software. The performance of the entire
      system may be verified in the field with just two clicks of the mouse.
    • Since the RAS-24 acquisition unit is separate from the
      controller (the laptop), the controller may be easily upgraded
      to faster, more capable models as they become available.
     
    24-channel Layout

    Typical 24-channel setup

    48-channel Single-Line Layout

    Typical 48 Channel Single Line Layout


    Specifications:
    Number of Channels: 12 or 24 per RAS module, up to 240 channels per system (10 modules)
    Sample Intervals: 0.125, 0.25, 0.5, 1, 2 and 4 ms
    Record Length: 4 ms - 64 sec, 2 ms - 32 sec, 1 ms - 16 sec,
    .5 ms - 8 sec,.25 ms - 4 sec, .125 ms - 2 sec
    Multiline Operation: 10 lines
    CDP Operation: 2D: Automatic or manual roll of entire spread
    3D: Managed by RAS-24 script editor
    Stacking: Vertical stack
    Cable: One 12 takeout cable for 12 channel system. Two for 24 channel system
    Laptop to RAS Interval: 1200ft maximum 3 pair wire
    RAS to RAS Interval: 5000ft maximum 2 pair wire
    Recording Format: SEG-2, SEG-D 8038, SEG-D 8058
    A/D Resolution: 24 bits using Delta-Sigma A/D converters - one per channel
    Preamp Gain (PG): 12db, 24db, 36db or 48db, remotely selectable
    Frequency Response: .125 ms: 2 - 3300Hz, .25 ms: 2 - 1650 Hz, .5 ms: 2 - 825 Hz,
    1 ms: 2 - 412 Hz, 2 ms: 2 - 206 Hz, 4 ms: 2 - 103 Hz
    Dynamic Range: 112db @ 2 ms PG=36db, 117db @ 2 ms PG=12db (typ)
    Distortion (THD): .005% at 25 Hz, 2 ms sample interval (typ)
    Crosstalk: Greater than 90db
    CMR: Greater than 90db @ 60 Hz
    Max Input Signal: 880 mVRMS @ 12db, 55 mVRMS @ 36db
    Input Noise: .21 mVRMS @ 2ms PG=36db, 1.6 mVRMS @ 2ms PG=12db (typ)
    Anti-Alias Filters: 4 ms 103 Hz, 2 ms 206 Hz, 1 ms 412 Hz, .5 ms 825 Hz,
    .25ms 1650 Hz, .125ms 3300 Hz
    Test Oscillator: 10, 25, 50, 60, 100, 125, 200, 250 Hz
    Amplitude adjustable in 10 mV steps
    Instrument Tests: Internal digital tests, battery voltage, internal voltage, crosstalk,
    amplifier pulse, CMR, amplifier noise, dynamic range, gain &
    phase similarity, system timing, communications, trigger verification
    Line Tests: Geophone pulse, geophone similarity, geophone resistance, cable leakage
    Connectors: Two 27-pin NK-27-21C connectors for geophone spread cable,
    3-pin Bendix for trigger, two 6-pin Bendix for data,
    3-pin Cannon for power
    Power: 12 volts nominal.
    Standby: 60ma / Acquisition:12 Chs: 1A, 24 Chs: 2A
    Physical: 27 x  34 x 15 cm,  5 kg
    Operating Temp: -30 to 70°C


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    ABEM Instrument AB | Allén 1 | S-172 66 Sundbyberg | Sweden
    Phone: +46 8 564 88 300 | Email: sales@abem.se