Benthowave Instrument Inc.

BENTHOWAVE INSTRUMENT INC. Acoustic Transducer & System 

Low Noise Hydrophone

Low Noise HydrophoneLow Noise HydrophoneLow Noise HydrophoneLow Noise HydrophoneLow Noise Hydrophone

BII-7120 Low Noise Hydrophone

BII-7120 series hydrophones are optimized to possess self noise levels below sea-state zero from 1Hz to 200kHz range. 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 over the cable. The cable terminals available are audio connectors, BNC and underwater mateable connectors.

Several optional mounting parts are available for installation on portable-mounting apparatus, submersibles, pipe, tank or vessel.

How to calculate self-noise level of BII-7120 series:
Noise Density Pn in μPa/√Hz = 10^[(Noise Density in dB μPa/√Hz)/20];
Input Self-Noise Pressure Level in dB μPa = 10*log[∫(Pn*Pn)df)].    f: frequency in Hz.

Suggested Application  
Noise Measurements Underwater
Passive Acoustic Monitoring (PAM System)
Natural/Anthropogenic/Bioacoustic Underwater Sounds
Reference Hydrophone for Transducer Calibration
Sonobuoy, Dipping Sonar, Array Processing
Laboratory and industrial measurements
Frequency range: 1Hz to 200kHz Equivalent noise level well below sea-state zero
Underwater mateable connector/BNC/TRS/XRL Omnidirectional over wide frequency range
Cable driving capability: 200m Single-ended/unbalanced or differential/balanced output
Very low interference to acoustic field under test Highly corrosion resistant
Related Products  
BII-1000 Hydrophone Preamplifier BII-8000 Recording, Analysis & Playback
BII-5020 Headphone Power Amplifier BII-8006 Portable Digital Recorder


Hydrophone Sensitivity &
Noise Spectrum
Size ΦDxL
BII-7121 OCV & Noise Density 1 Hz to 60 kHz Omni@40kHz 240°@20kHz 300 m 350 Φ33x80
BII-7122 OCV & Noise Density 1 Hz to 100 kHz Omni@40kHz 240°@40kHz 300 m 350 Φ27x100
BII-7123 OCV & Noise Density 1 Hz to 150 kHz Omni@60kHz 240°@60kHz 300 m 350 Φ21x90
BII-7125 OCV & Noise Density 1 Hz to 200 kHz Omni@80kHz 220°@80kHz 300 m 350 Φ15.5x60
Acceleration Sensitivity: < 40 dB re µPa/(m/s²)
Overload Pressure Level: 20*log(Maximum Output/2.828) - Sensitivity (dB μPa).
Bespoke Sensitivity: Yes, Please specify the sensitivity when ordering.
Built-in Preamplifier: Yes. The gain of preamplifier can be customized to achieve customized sensitivity of BII-7120 series.
Customized Filter: Customized High Pass filter and Low Pass Filter. Specify when ordering.
Maximum Output: (Supply Voltage - 3) Vpp
Output Type: 1. Default: Single Ended Output (SE), Append SE to the listed part number.
2. Differential Output (DF), Append DF to the listed part number.
Supply Voltage: +7.5 to +30VDC
Current (Quiescent): 12mA
Suggested DC Supply:   +9VDC Battery, Marine Battery, Automobile Battery, Fixed Low Noise DC Linear Power Supply, Not Included.
DO NOT use variable power supply whose maximum supply voltage is higher than the rated voltage.
DO NOT use switching mode DC power supply.
Mounting Options:  1. Default: Free Hanging (FH)
2. Free-hanging with Male Underwater Connector (FHUWC)
3. Thru-hole Mounting with Single O-ring (THSO)
4. Thru-hole Mounting with Double O-ring (THDO)
5. Bolt Fastening Mounting (Plastics): (BFMP)
6. Bolt Fastening Mounting (Stainless Steel): (BFMSS)
7. Thru-hole Mounting + Free Hanging (THFH)
Click Transducer and Hydrophone Mounting for more detailed information on mounting/installation.
Cable Length: 1. Default: 10m; 2. Customized: up to 200 m
Cable: Shielded Cable (ΦD=6.5mm)
Connector: 1. Default: Wire Leads (WL)
2. BNC Male (BNC)
3. 3.5 mm (⅛″) TRS Plug (TRS35)
4. ¼″ (6.35 mm) TRS Plug (TRS635)
5. XLR Plug (XLR)
6. Underwater Mateable Connector (UMC)
7. MIL-5015 Style (5015)
8. +9VDC Battery Snap (BS) (Exclusive to preamplified hydrophone)
9. Custom (custom)
Operating Temperature: -10°C to +60°C
Storage Temperature: -40°C to +60°C
How to Order: Click How to Order.
Hydrophone Wiring: Click Hydrophone Wiring for detailed wiring information.
Receiving Array: Array & Aperture Design

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