Acoustic/Vibration Conditioner

Unique Features Ideal for Vibration Measurements on Submarines and Surface Ships in High EMI Environments

Precision Filters’ 28918A 8-Channel CVLD/IEPE Conditioner conditions IEPE accelerometers, CVLD accelerometers, In-Line Pre-Amps and Voltage signals and is particularly suited for making underwater acoustics noise and vibration measurements, especially in high magnetic field environments.

The 28918A is a dual mode card operating in either CVLD mode or IEPE mode.

In CVLD mode, the 28918A is compatible with specialized CVLD sensors that have enhanced immunity from EMI noise sources plaguing modern day submarines and surface ships. In CVLD sensors vibration signals are presented as a proportional output current, rather than proportional voltage as in traditional IEPE type accelerometers. The 28918A converts and conditions the variable output current and provides a clean, amplified data acquisition ready voltage signals for attached A/D convertor systems. Using the 28918A, small AC current signals are detected even in the presence of large noise signals common with cabling in high magnetic field environments. The constant voltage CVLD excitation is programmable to 10 or 15 V. A buffered system-test bus signal can be injected to the CVLD input circuit or connected to the third wire connection to a CVLD equipped with CAL input.

In IEPE mode, the 28918A is compatible with either floating or grounded sensors with programmable IEPE current up to 12 mA. The 28918A provides an overall amplifier gain up to 1024 and up to 30 kHz filtered or 190 kHz wideband bandwidths.

The 28918A 8-Channel CVLD/IEPE Conditioner is a member of the Precision 28000 family of signal conditioners.

Learn more about the 28000 Signal Conditioning System >

  • Precision Filters’ 28918A 8-Channel CVLD/IEPE Conditioner

    The 28918A CVLD/IEPE Conditioner Designed for High EMI Environments


    • Vibration Measurements in High Magnetic Noise Environments
    • Platform Noise
    • Structure-Borne Noise
    • Acoustic Receivers
    • Dynamic Vibration, Load, Torque, Pressure, and Force Measurements in Industrial Environments
    • Machine Health Monitoring
    • Structural Response Tests

28918A 8-Channel CVLD/IEPE Conditioner Features:

  • Eight channels per card
  • 128 channels per 28016 chassis
    64 channels per 28008 chassis
    32 channels per 28004 chassis
  • IEPE, CVLD or voltage inputs
  • Isolated IEPE mode to break cabling ground loops
  • Up to 30 kHz “filtered” bandwidth or 190 kHz “wideband” bandwidth
  • Compatible with Constant Voltage Line Drive (CVLD) sensors
  • Programmable IEPE current to 0, 4, 8 and 12 mA
  • Programmable CVLD excitation 10 or 15 V
  • Programmable amplifier: x½ to x1024 with 0.05 x steps
  • 4-pole low-pass filters with filter bypass (wideband)
  • 0.2% measurement accuracy
  • 15nV/√Hz noise floor
  • Sensor CAL signal for CAL equipped CVLD sensors

View the 28918A 8-Channel CVLD/IEPE Conditioner Specification Sheet >