Deprecated. Please see the S1n hydrophone, which offers practically identical performance and utilizes the same sensing element.

The AS-1 delivers a wide linear broadband response with a passive sensing element, enabling its use as an omnidirectional projector (transmitter) as well as a receiver. Response is omnidirectional in the human auditory bandwidth, and 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.

The AS-1 is a passive hydrophone with no built-in signal conditioning. Use it directly with your oscilloscope or DAQ device, or pair it with the PA4-BO or PA6 preamp and any digital recorder or sound interface for high-quality, low-cost underwater sound analysis.

Connector

The AS-1 is passive and requires a high-impedance input. Connecting it directly to a low-impedance input (such as a line input or a typical microphone preamp) will result in very low output and poor low-frequency response.

Non-Removable Weight Option

The AS-1 hydrophone can be optionally assembled with our WT150g sliding stainless steel weight assembly for sinking the hydrophone. There are several advantages to placing the weight on the cable rather than building it into the hydrophone:

  • When the hydrophone is dropped, the cable flexes and deflects that impact away from the hydrophone.
  • It dampens vibrations in the cable that would otherwise be induced into the hydrophone signal as acceleration noise.

Custom cable length

While we can make any length of cable, performance can be impacted above 30-meters. Long cables affect high-frequency response. Consider cable capacitance, input impedance, signal conditioning, and required bandwidth.

Deprecated. Please see the S1n hydrophone, which offers practically identical performance.

The AS-1 utilizes a passive piezo sensing element. There is no preamp or impedance buffer circuit within the hydrophone, which allows it to be used as an omnidirectional projector (transmitter) as well as a receiver. The following specifications were obtained from the average of a limited sample group and were measured at the end of 9-meter cable lengths.

Acoustic performance

Linear range
1 Hz to 100 kHz (±2 dB)
Receiving sensitivity1
-208 dBV re: 1 µPa (40 µV / Pascal)
Transmitting sensitivity
140 dB SPL re: 1 µPa, 1 Vrms input at 1 meter, 90 kHz
Maximum input voltage
30 V p-p (continuous)
150 V p-p (<10% duty cycle, <100 kHz)
Nominal capacitance
5 nF ±15% (plus cable @ 118 pF/m)

Directivity

Horizontal directivity (20 kHz)
±0.2 dB
Horizontal directivity (100 kHz)
±1 dB
Vertical directivity (20 kHz)
±1 dB
Vertical directivity (100 kHz)
+6 dB / -11 dB

1 The AS-1 is not individually calibrated. Standard quality control allows for a ±3 dB 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.

Physical

Operating depth
200 meters
Survival depth
350 meters
Operating temperature range
-10 °C to +80 °C
Output connection
BNC (standard); bare wire available
Size
Ø12 mm × 40 mm
Weight in air
8 grams (plus cable @ 28 g/m)
Cable length
10 meters standard. Any length on request.
Cable jacket
Polyurethane, 4.5 mm OD
Encapsulant
Polyurethane

 

Select plots

AS-1 hydrophone response charts

NOTES:

Data obtained from US Navy, Underwater Sound Reference Division, Newport, June 2013, measurements taken at end of 9-meter cable.

Calibration

The Aquarian AS-1 hydrophone is not individually calibrated during manufacturing. Instead, it undergoes standard quality control procedures that include nominal sensitivity, capacitance, leak test, and listening test.

We no longer provide additional calibration services through the US Navy Underwater Sound Reference Division. For precise applications requiring detailed calibration data, the customer must arrange their own calibration.