Benthowave Instrument BII7120 Series Quick Start Manual

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BII7120 Series Low Noise, Low Power, and Low Frequency Hydrophone: Noise Level Below Sea State Zero
BII's low noise hydrophones are optimized to possess self noise levels below sea-state zero with omnidirectional response in low frequency range and toroidal response
in high frequency range. Its streamlined hemispherical dome minimizes drag force and hydrodynamic noise. The power consumption can be customized to be 600µA
quiescent current at 5VDC for battery powered underwater instrumentation. A spatial array of multiple hydrophones can be set up for directional measurement system.
The hydrophones can measure underwater sounds and pressure fluctuations down to 0.1Hz infrasonic sounds: surface waves (Wave-height Sensor), turbulences, seismic,
ocean traffics, industrial noises, precipitations, biologics, ...
With these low power hydrophones, battery and system lifetimes are extended, and lighter portable systems with lower-capacity batteries can be achieved. Its compact
small size avoids interferences to acoustic field under test. The preamplifier integrated in the hydrophone can drive cable up to 200m without signal loss. Available cable
terminals include audio connectors (TRS, XLR), BNC, and underwater mateable connectors. The housing and mounting part are corrosion resistant plastics and/or stainless
steels.
Underwater Sound Listening, Recording, and Communication
Typical Applications
Underwater Sounds Recording, Listening, and Communication, Noise Measurement, Marine Bioacoustics, Passive Acoustic Monitoring (PAM System).
Coastal/Offshore Processes, Engineering & Management, Wave-Structure Interaction, Wave-height Sensor, Wave and Tide Recorder/Logger.
Surface Waves, Ocean Turbulences, Hydrodynamics, Marine Geophysics, Battery-Powered Instruments: Sonobuoy, Recorder, Transponder, Acoustic Release...
Questions
How do I set up my professional sound recorders to work with BII Hydrophones?
1. BII hydrophones have their own DC power supply to support Line Input of recorders, and Do NOT use phantom power 48V which may destroy the hydrophones.
2. Maximum Input Level (Line Input) of recorders should be large enough to avoid saturation or clipping during recording.
Equivalent Input Noise of recorders should be low enough for the recorders to be sensitive to weak signal of the interest.
3. Sampling Rate of the recorder should be fast enough to avoid missing high frequency sound of the interest. Generally, the Sampling Rate should be at least two times
greater than the maximum frequency of sound.
4. Calculate the memory size of data storage according to sampling rate, resolution, sampling channels, and recording time, and use suitable recording media.
5. Calculate battery service life according to battery power and consuming current.
6. When the cable is greater than 5m, balanced signal or differential signal is recommended to be in use over the cable.
How do I playback the recorded sounds in water?
System Setup: Recorder (Recorded Sounds) with Line or Phone Output ->
Benthowave Instrument Inc.
Underwater Sound Solutions
BII Hydrophone
Audio Power Amplifiers
benthowave.com Revised on 2025/02/18
BII7123FG
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Speaker
Sound Recorder
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Oscilloscope
BII Hydrophone
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Sound Recorder
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-> Impedance Matching Device
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