Autonomous acoustic recorder

URec384k - Programmable Underwater Acoustic Recorder

The URec384k is delivered with a customized DODOTRONIC recording board sampling up to 384kHz set in an acrilic resin canister with PET caps.

The standard hydrophone is a Sensor Technology SQ26-05 pre-amplified hydrophone on one cap.
Several other hydrophones models are available for integration, including the Aquarian Audio H2c, the Aquarian Scientific AS-1 and the whole series of Cetacean Research Technology sensors.

The canister can be delivered with different battery sets, and can go down to more than -500m, depending on the provided hydrophone.

A magnetic switch can be used to start/stop the power supply externally without opening the canister.

A custom preamp has been developed to fit the levels and the output impedance of the hydrophones, providing a no-noise signal to the recorder.

O-rings on each end provide extra resistance to high pressures, while the 1cm wall safely keeps the instrument dry.

Programmable via bluetooth connection and a custom software for your Android phone, can be set to follow a duty-cycle scheme (record for an x period and then pause for a y period) or specific time intervals (record from xx:xx to yy:yy and then again from zz:zz to tt:tt …).

The URec384k, with its DODOTRONIC board, is probably the most flexible acoustic monitoring device on the market.

Battery capacity can deliver weeks of sampling, all stored on the mSD on the board.
A precise RTC (real-time clock) marks the recordings on the filename for later analysis.

A magnetic switch can put the system in stand-by, without opening the canister, while waiting for deployment.

Basic specifications for the URec384k standard model

Sampling rate: user selectable up to 384ks/s @ 16bits
Frequency response of the recorder: 10Hz to 190kHz
Gain: user selectable 1, 10x, 100x
Power supply at sensor end, for custom applications: 5V
Memory: tested up to 256GB, testing 400GB mSD cards
Real-time clock: with self powered battery
Hydrophone: Sensor Technology SQ26-05 (more sensors available on request)
Pressure resistance: -500m and over
Battery life: see here on the right

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Battery life and recordings
Battery life estimation for this kind of equipment is quite complicate.
The tests we have performed show the following:
Using Energizer Ultimate Lithium AA Batteries, declared to have a capacity of 3500mAh we obtain a 9V power feed that is conditioned via a step-up/step-down micro inverter.
The regulator delivers 5V whatever the input is between 3..11.8VDC with an efficiency of around 90%. Temperature does not affect battery capacity much (for these lithium series).
The recorder drains around 40mA while recording. While pausing the system drains around 0,2mA.
With these numbers we can assume about 60hrs of total recordings with the standard 6xAA setup.
Sampling at 384ks/s the data will be around 170GB (we usually deliver a 256GB mSD with the system).

These recordings can be programmed over tens of weeks, as the very low quiescent drain allows over 10k hours of stand-by.
Real-life testing being performed.

Underwater acoustic recorders