Ocean Seven 404 CTD Logger
VERY LOW POWER, SELF-RECORDING, UV-ANTIFOULING, ARCTIC, ANTARCTICA, BRINE, MOORINGs, ROVs, AUVs
The OCEAN SEVEN 404 CTD combines very high-quality electronics with exceptional sensors accuracy fulfilling the demand for a self-recording high performance CTD probe with very compact dimension and very low power consumption. This CTD can be easily integrated/adapted to third-party systems like floating profilers and/or oceanographic moorings, ROVs and AUVs. IDRONAUT prides itself on the design of its full ocean depth, pump-free, low-maintenance sensor, central to which is the high accuracy seven-platinum-ring quartz conductivity cell. The self-flushing sensors makes this CTD ideal for deployment in Arctic and Antarctica. The OS404 CTD standard interface is RS232C; other optional interfaces are: TTL, RS485 and wireless. The OS404 housing can be manufactured with either a 316 grade L stainless steel or titanium allowing deployment to depths of 1000 or 7000/10.000 dbar respectively.
Automatic, real-time data transmission compatible with: Bluefin and OEX AUVs are available, together with a proprietary data transmission format. To further reduce weight and size a shorter housing is available upon request.
Features a very fast platinum resistance thermometer (response time: 50 ms). Negligible self-heating effect.
Optionally combined C/T sensor featuring a 7 ms fast thermistor (20 ms after processing) integrated in the conductivity cell is available upon request.
The high accuracy seven-platinum-ring quartz conductivity cell (patented) can be cleaned in the field without the need for re-calibration. This unique quartz cell employs a large diameter (8mm) and a short length (46mm) to guarantee self-flushing and minimal fouling during long-term deployment even in biologically active waters. Furthermore, optionally two UV-LED (Ultraviolet, 280 nm @500µW, Light-Emitting Diode) can be integrated into the conductivity cell, sterilizing the sample under measurement, thus avoiding the early growth of biofouling inside the quartz measuring cell.
The OS404 CTD is equipped with a 4-Gbyte internal non-volatile SD memory which allows the storing of about 250 M data sets each one being composed of the reading of installed sensors plus the acquisition date and time. Different types of battery can be installed in the CTD housing.
The standard battery pack are:
Whenever the OS404 operates in Timed, Burst and Conditional modes, the battery endurance is considerably extended because the OS404 enters a deep sleep mode between acquisitions and drains only 4µAh from the battery. For instance, by monitoring every hour, the OS404 (CTD only) can run for about 9 years on a single Lithium size “C” cell.
(1) Other standard pressure transducers, immediately available, have: 10, 40, 100, 200, 500, 2000, 4000, 7000 dbar ranges.
(2) At 1 m/second flow rate. (3) A special calibration is needed.
The fundamental properties of seawater like: Salinity, Sound Speed, Water Density are obtained using the algorithms described in the UNESCO “Technical papers in marine science no.44 – Algorithms for computation of fundamental properties of sea water”.
The fresh water properties like: TDS (Total Dissolved Solids) and Conductivity corrected at 20°C and 25°C are automatically calculated.
(1) High precision pressure transducer have immediately available: 100, 2000, 4000, 7000, 10000 dbar ranges.
Idronaut programmes allow the operator to configure the OS404 data acquisition, logger functions and upload data from the memory. They are:
It is also available an AUV version having shorter housing.
Please contact Idronaut for further information.