Broadband measurement hydrophone
The AS-1 is designed to provide maximum sensitivity in a small size while also providing a linear response in the bandwidth of the highest-quality commercial digital sound recording interfaces. Response is omnidirectional in the human auditory bandwidth, as well as omnidirectional in the horizontal axis at all frequencies (theoretical). Given these qualities, the AS-1 is well-suited for absolute underwater sound measurements in marine and industrial environments. It can also be used as an omnidirectional reference projector.
Use directly with your scope or DAQ device or use with the PA6 preamp and any digital recorder or sound interface for high-quality, low-cost underwater sound analysis.
Fitted, breathable EVA case included with cable lengths of 20 meters or less (longer cable assemblies will not fit in case and will be bulk shipped in allowable packaging).
- Linear range: 1Hz to 100kHz ±2dB
- Receiving Sensitivity: -208dBV re 1μPa (40μV / Pascal)
- Transmitting Sensitivity: 140dB SPL re 1μPa, 1Vrms input at 1meter, 90kHz
- Maximum Input Voltage: 30V p-p (continuous); 150V p-p (<10% duty cycle, <100KHz)
- Horizontal Directivity(20kHz): ±0.2dB
- Horizontal Directivity (100kHz): ±1dB
- Vertical Directivity (20kHz): ±1dB
- Vertical Directivity (100kHz): +6dB -11dB
- Operating depth: 200m
- Survival depth: 350m
- Operating temperature range: -10°C to +80°C
- Nominal capacitance: 5nF +/- 15% (plus cable @ 118pF/m)
- Output connection: BNC (standard)
- Size: 12mm D x 40mm L
- Weight (in air): 8g (plus cable @ 28g/m)
- Cable length: 9 meters standard. Any length on request.
- Cable Jacket: Polyurethane, OD: 4.5mm
- Encapsulant: Polyurethane
The preceding specifications were obtained from the average of a limited sample group and were measured at the end of 9-meter cable lengths. The AS-1 is not individually calibrated. Standard quality control allows for a +/- 3dB deviation of nominal sensitivity plus measurement error with compensation for cable attenuation. Thus, any given AS-1--especially those with longer cable lengths--can deviate from the published specifications. Aquarian Scientific attempts to represent its products fairly, but no guarantee of compliance is offered.
See User Manual and Charts for additional information.
No Weight: Hydrophone is close to neutral buoyancy.
Weight installed: 150-gram adjustable cable weight. Secured to cable with compression thumbscrew. Permanently installed, but can be moved up and down the length of cable and locked into desired position. Assists in sinking the hydrophone and dampens vibrations in cable. Low-drag shape. Placing mass on the cable (rather than on the hydrophone) minimizes acoustic reflections and minimizes the likelihood of damage to hydrophone when dropped. Weight can also serve as a point to clamp flooded rubber tube for control of flow noise around hydrophone while towing. Stainless Steel with rubber collet and plastic thumbscrew. OD = 25mm.
Cable length is easily modified. 9-meters is the base length. We can shorten this, but the price remains the same. For longer cables, buy cable separately and leave notes on order form to verify preferred cable length. Please note that, with very long cables, output will be attenuated due to loading from cable capacitance. Keep cable length between AS-1 and preamp, such as PA6, to a minimum for best performance. Cable lengths of more than 30 meters not recommended.
BRC Engineering has designed a coupler for the AS-1 to be used with the G.R.A.S. pistonphone calibrator. For sales and rental of these calibration items, please contact Richard Craig at BRC: 707-226-3332 or brcnorcal<at>aol<dot>com.