URec384k - Underwater Acoustic Recorder
The standard hydrophone is a Sensor Technology SQ26-05 pre-amplified hydrophone on one cap.
Several other hydrophones models are available for custom 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 two different battery setups: 3xD batteries or 3x3xAA batteries.
The unit can go down to more than -500m, depending on the provided hydrophone and possible additional limitations.
A magnetic switch can be used to start/stop the operation while in the field without opening the canister.
O-rings on each end provide extra resistance to high pressures, while the 1cm wall safely keeps the instrument protected.
Programmable via bluetooth: a bluetooth connection and a custom software for your Android phone, can be used to set-up 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 …).
Battery capacity can deliver weeks of sampling, all stored on the single mSD on the board.
A precise RTC (real-time clock) marks the recordings on the filename (timestamp naming) for later analysis.
A magnetic switch can put the system in stand-by, without opening the canister, while waiting for deployment.
Sampling rate: user selectable up to 384ks/s @ 16bits
Frequency response of the recorder: 10Hz to 190kHz
Gain: user selectable 1x, 10x, 100x
Power supply at sensor end, for custom applications: 5V
Memory: tested up to 400GB mSD cards
Real-time clock: with additional coin battery
Hydrophone: Sensor Technology SQ26-05 (more sensors available on request)
Pressure resistance: -500m and over depending on the hydrophone
Battery life: see on this page
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 3 x 4,5V 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 have measured nearly 15days of continuous recording with the 3 x 3 - AA setup.
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.