Please visit regularly this section for updates and information to help you operating the AURAL properly.
Specifications are subject to change without notices.
User Guide (last update: November 2016)
Get the AURAL ready for a 2nd deployment (Maintenance)
Get the AURAL ready for storage (Maintenance)
Note that any replacement procedure must be done only after recommandation from Multi-Électronique.
This section provides answers to some of the most frequently asked questions about the AURAL. If your questions is not answered here, or you need more information, please get in touch with us.
Questions regarding AURAL Setup and InfoWAV
Questions regarding batteries
Questions regarding the mooring
- The latest software update is always available on our website. We recommend visiting regularly this section to make sure you always run the latest version. You must remove old version through the usual uninstalling procedure before installing new one.
- The software you received with your AURAL are the most up-to-date during that period. But, we recommend visiting regularly the User section to make sure you always run the latest version. You must remove old version through the usual uninstalling procedure before installing new one.
- No, AURAL Setup and InfoWav are compatibles with Windows 2000, XP and 7.
- In recent years, battery manufacturers' specifications have changed to meet RoHS standards. Battery no longer offers a constant drain of 20,5 Amp/Hrs as before, but now ~15 Amp/Hrs.
- We recommend Energizer EN95 alkaline "D" cells. This model performed the best in our lab tests. Duracell and Panasonic are also popular brands used by our customers.
You can also get battery pack (for alternate battery rack) conceived by Multi-Electronique. Click here for more information.
- Tests performed so far show that a water temperature of ± 0 °C (32 °F) has no significant impact on the battery lifetime.
- Before inserting new batteries in a AURAL (with conventional battery rack), you must verify each of them with a battery tester. Even if they come directly from the manufacturer, it is possible to come across a dead battery. Batteries in the AURAL are connected in series. One defective battery can affect an entire string. You risk therefore losing weeks or months of recording due to a single defective cell.
This recommendation is for conventional battery rack only. Battery packs made by Multi-Electronique have been tested and are ready to use.
- The tested depth is 300 meters (984 ft).
- We recommend using new anodes after each deployment. Anodes sustainability depends on several factors:
These hostile conditions accelerate corrosion and the anodes are designed to further protect better the stainless steel components.
- The maximum sampling rate is 32768 Hz.
- AURAL memory hard drives depend on the trend and market availability. Nowadays, the maximum size of hard drive with PATA (Parallel AT Attachment) interface is 320 GB. You can get a double hard drive adaptation kit to double the memory of your AURAL (640GB).
- Recent AURALs have firmware V4.1.3.
The latest firmware for AURAL running with older Printed Circuit Board V3 is V3.4.0
- It may be in standby mode. Since the AURAL is designed for energy saving, it will get into standby mode after 5 minutes of inactivity in configuration mode. To wake it, hold the SETUP button of the control box and press the RESET button. You must hold the SETUP until the message "Entering in setup" appears in the AURAL Setup message box. You will be able to continue configuration using AURAL Setup.
- It depends on many factors: the number of battery, the sampling rate, the hard drive memory, the size of the WAV files, etc.
There is no better configuration. We recommend that you base yourself on the information that you already know, and try several combinations in AURAL Setup. By pressing "Compute", the software estimate the battery and recording lifetime corresponding to your criterias.
Notice also that a very large wav file may take a long time to open later.
- The sonar equation is:
SPL(dB re 1µPa) = Vdet ● RS ● G
SPL: Sound pressure level detected by the AURAL (µPa)
Vdet: Acoustic signal detected by the hydrophone in dB, therefore 20 log (signal in volt). The AURAL measures over a range of ± 2V, converted to 16 bit
RS: Receiving sensitivity (~165 dBV / µPa, (see HTI specification))
G: AURAL gain (16, 18, 20 or 22 dB)
Vdet = 2V
(dB re 1 µPa)
|* Minimum recorder SPL at
Vdet = 1 bit = ±1/(2^15)) * 2V
(dB re 1µPa)
* In practice there is a self noise of a bew bits that should be considered.
Note that the receiving sensitivity varies with frequency. The (RS vs. frequency) curve is obtained by users from their calibration according to ANSI calibration standards. Hydrophone RS nominal value is provided by HTI manufacturer. The (RS vs. frequency) curve measured by users is relatively flat (± 1 dB), in the low frequency band below 5-10 kHz.