Benthowave Instrument Inc.

BENTHOWAVE INSTRUMENT INC. Acoustic Transducer & System 

Flush-Mounting Transducer

Flush-Mounting TransducerFlush-Mounting TransducerFlush-Mounting TransducerFlush-Mounting Transducer

BII-7720  Flush-Mounting Transducer

BII-7720 series transducers mount through a hole or counterbore hole cut in the housing of underwater instruments, apparatus, vehicles or the wall of swimming pools. The flush-mounting design of these transducers minimizes surface discontinuity and allows for smooth water flow over the surfaces, meaning lower induced acoustic noise (hydrodynamic noise, flow noise), less drag/resistance, avoidance of accidental collision and better acoustic performance for the underwater devices in motion such as towed fish/bodies, ROV/AUV/UUV, robots, etc... Low-profile flush installation protrudes only 4.75mm outside the housing with streamlined flange.

BII-7720 transducers emit and receive conical beams, and are designed for use as components in communication/positioning, navigation, fishery, oceanography, Seafloor-mapping, Marine Animals research, etc....

The housing can be mounted on different materials such as woods, plastics, fiber glass, ceramics and metals. Marine sealants shall be used for sealing, bedding and installation. The depth rating is limited by the sealing performance of the cured marine sealants.

If you do not find any transducer suitable to your project, please contact BII for custom designs on size, operating frequency, beam width, mounting, etc...

Technical Notes:
The TVR of the transducer is NOT affected with the cable length.

Receiving Sensitivity Loss Over Extension Cable (dB) = 20*log[Ch/(Ch+Cc)];   Ch - Transducer Capacitance; Cc - Extension Cable Capacitance.
Array directivity function = (directivity function of array element) * (directivity function of array pattern).

Applications  
Towed Bodies, Vessels in Motion, Sonobuoy
Linear, Planar and Conformal Array
LBL/SBL/USBL Positioning System
Communication/Remote Control/Telemetry
Characterization and Testing of Materials
TS & Sv Measurement/Assessment
Object Detection and Tracking, Obstacle Avoidance
Precision Distance Gage, Altimeter, Liquid Level
Sonar Navigation, Inspection and Survey
Surface Continuity for Low Acoustic Perturbation
Direction-finding Sonar System
Monitoring Aquarium/Pool Safety/Alarm System/Alarm System/Underwater Security
Bioacoustic Research of Marine Animals
Sound Velocity Profiler
Fishery and Plankton
Bathymetric Sounder, Depth Sounder
FM/Chirp Transducer/Sonar/Fishfinder
Parametric Transducers
Features  
High Sensitivity
Broadband (Low Q)
Conical Beam
Low Hydrodynamic/Flow Noise
Easy Installation/Mounting/Removing
20kHz to 2MHz, Single or Dual Frequency
Related Products    
Power Amplifier Transmitting and Receiving Switch Flush-Mounting Hydrophone

Installation/Mounting

Mechanical Size:  No Electronics Mechanical Size: Built-in Electronics Flush-Mounting with Counterbore Hole Low-profile Flush Mounting
Flush-Mounting Transducer Flush-Mounting Transducer  Flush-Mounting Transducer  Flush-Mounting Transducer 

Specification

TVR: Transmitting Voltage Response (dB µPa/V at 1m); RVR: Receiving Voltage Response (dB V/µPa);  θ: Beamwidth at -3dB;
fs: Resonant Frequency (kHz); Q: Quality Factor=fs/(-3dB Bandwidth); ΦD: Flange Diameter; L: Thread Length.
BII-7720 Series Single-Frequency Transducers
Transducer fs
(kHz)
TVR RVR Beam
Angle
Q Maximum
RMS Power
Side
Lobe
Maximum Wall
Thickness (mm)
Size
ΦDxL
Mounting
Thread
BII-7722/33 33 131 -173 64° 3 600W No 56mm Φ80x66 M56x1.5
BII-7723/33 33 136 -173 44° 3 600W -20dB 56mm Φ100x66 M76x1.5
BII-7722/37.5 37.5 133 -174 56° 3 600W No 56mm Φ80x66 M56x1.5
BII-7723/37.5 37.5 138 -174 39° 3 600W -20dB 56mm Φ100x66 M76x1.5
BII-7722/38 38 136 -174 55° 3 600W No 56mm Φ80x66 M56x1.5
BII-7723/38 38 141 -174 38° 3 600W -20dB 56mm Φ100x66 M76x1.5
BII-7721/45 45 132 -175 78° 3 600W No 41mm Φ59x51 M35x1.5
BII-7722/45 45 139 -175 47° 3 600W -20dB 41mm Φ80x51 M56x1.5
BII-7723/38 45 144 -175 32° 3 600W -20dB 41mm Φ100x51 M76x1.5
BII-7721/50 50 133 -169 70° 3 600W No 41mm Φ59x51 M35x1.5
BII-7722/50 50 141 -169 42° 3 600W -20dB 41mm Φ80x51 M56x1.5
BII-7723/50 50 148 -169 29° 3 600W -20dB 41mm Φ100x51 M76x1.5
BII-7721/70 70 139 -174 50° 3 600W No 29mm Φ59x39 M35x1.5
BII-7722/70 70 147 -174 30° 3 600W -20dB 29mm Φ80x39 M56x1.5
BII-7723/70 70 154 -174 21° 3 600W -20dB 29mm Φ100x39 M76x1.5
BII-7721/100 100 142 -177 35° 3 600W -20dB 29mm Φ59x39 M35x1.5
BII-7722/100 100 150 -177 21° 3 600W -20dB 29mm Φ80x39 M56x1.5
BII-7723/100 100 157 -177 15° 3 600W -20dB 29mm Φ100x39 M76x1.5
BII-7721/120 120 149 -190 29° 3 600W -20dB 18mm Φ59x28 M35x1.5
BII-7722/120 120 156 -190 17.6° 3 600W -20dB 18mm Φ80x28 M56x1.5
BII-7723/120 120 163 -190 12° 3 600W -20dB 18mm Φ100x28 M76x1.5
BII-7721/150 150 151 -192.5 23° 3 600W -20dB 18mm Φ59x28 M35x1.5
BII-7722/150 150 159 -192.5 14° 3 600W -20dB 18mm Φ80x28 M56x1.5
BII-7723/150 150 166 -192.5 9.6° 3 600W -20dB 18mm Φ100x28 M76x1.5
BII-7721/200 200 158 -195 17.5° 3 600W -20dB 18mm Φ59x28 M35x1.5
BII-7722/200 200 165 -195 11° 3 600W -20dB 18mm Φ80x28 M56x1.5
BII-7723/200 200 172 -195 7.3° 3 600W -20dB 18mm Φ100x28 M76x1.5
BII-7721/300 300 163.6 -193 12° 3 500W -20dB 18mm Φ59x28 M35x1.5
BII-7722/300 300 172 -193 7.0° 3 600W -20dB 18mm Φ80x28 M56x1.5
BII-7723/300 300 179 -193 4.8° 3 600W -20dB 18mm Φ100x28 M76x1.5
BII-7721/420 420 169 -191 8.3° 3 500W -20dB 18mm Φ59x28 M35x1.5
BII-7722/420 420 178 -191 5.0° 3 600W -20dB 18mm Φ80x28 M56x1.5
BII-7723/420 420 185 -191 3.5° 3 600W -20dB 18mm Φ100x28 M76x1.5
BII-7721/600 600 174 -193 5.8° 3 500W -20dB 18mm Φ59x28 M35x1.5
BII-7722/600 600 181 -193 3.9° 3 500W -20dB 18mm Φ80x28 M56x1.5
BII-7723/600 600 186 -193 2.8° 3 500W -20dB 18mm Φ100x28 M76x1.5
BII-7721/1000 1000 174.3 -207.2 3.5° 3 500W -20dB 18mm Φ59x28 M35x1.5
BII-7722/1000 1000 180 -205 2.6° 3 500W -20dB 18mm Φ80x28 M56x1.5
BII-7723/2000 2000 184.6 -216.4 1.8° 3 500W -20dB 18mm Φ59x28 M35x1.5
BII-7720 Series Dual Frequency Transducers
BII-7728/50/200 50
200
147
160
-195
-196
38°
10°
4.6 600W -20dB 18mm Φ80x28 M56x1.5
BII-7728/50/300 50
300
147
172
-195
-193
38°
6.5°
4.6 600W -20dB 18mm Φ80x28 M56x1.5
BII-7728/50/420 50
420
148
185
-192
-191
38°
4.6°
4.6 600W -20dB 18mm Φ80x28 M56x1.5
BII-7729/33/200 33
200
143
162
-195
-196
28°
6.5°
4.6 600W -20dB 18mm Φ100x28 M76x1.5
BII-7729/33/300 33
300
143
174
-195
-193
28°
4.4°
4.6 600W -20dB 18mm Φ100x28 M76x1.5
BII-7729/33/420 33
420
144
186
-192
-191
28°
3.2°
4.6 600W -20dB 18mm Φ100x28 M76x1.5
Miscellaneous: BII-7720 Series Transducers
Beam Pattern: Conical Beam
Impedance Matching: BII-6000, Not included. Order separately, append IM to part number.
Customized to optimum load of the power amplifier: 4Ω to 16Ω, 50Ω, 75Ω, 100Ω, etc...
TR Switch: BII-2100 Transmitting & Receiving Switch. Not Included. Order Separately, Append TR to part number.
Temperature Sensor: 1. Default: No built-in temperature sensor.
2. Built-in NTC thermistor. When ordering, append TS to part number for integrating NTC thermistor in transducers.
Mounting: Flush Mounting: counterbore hole shall be cut.
Low-profile Flush Mounting: through-hole shall be cut.
Fastening Torque: ≤14Nm, a nut is included.
Marine sealants are NOT included.
Click Transducer and Hydrophone Mounting for more detailed information on mounting/installation.
Marine Sealants: BII does NOT provide Marine Sealants with the transducers. Buyer needs to buy Marine Sealants from buyer's local stores. Generally the stores that sell boats and boat repair part/material have marine sealants in stock, or buyer may use search engine to locate the suppliers online.
Maximum Operating Depth: ≤100m, limited by the sealing performance of the cured marine sealants over the mounting hole.
For deeper underwater deployment (maximum 300m), one option is that O-ring grooves are cut on the mounting wall and O-rings are used besides marine sealants or casting sealants.
Cable: 1. Shielded Cable (SC)
2. RG58 Coax (50Ω)  (Voltage Rating ≤ 50Vrms) (RG58)
Connector Options: 1. Wire Leads (WL)
2. BNC male (50Ω)  (Voltage Rating ≤ 50Vrms) (BNC)
    Warning: It is buyer's sole responsibility to make sure that the (female) BNC shield of the signal source is firmly
    grounded for operating safety before hooking up transducer to the signal source.
Operating Temperature: -10°C to +60°C
Storage Temperature: -40°C to +60°C
How to Order: Click How to Order.
Transducer Wiring: Click Transducer Wiring for detailed wiring information.
Transmitting Array: Array & Aperture Design
   
Cable Information: Nominal Impedance Cable Information: Nominal Impedance
Shielded Cable, Two Conductors 67 Ω RG58 Coax 50 Ω
Shielded Cable, Two Conductors 90 Ω RG174/U Coax 50 Ω
Shielded Cable, Four Conductors 52 Ω  

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