Ocean Seven 304 CTD LOGGER

LOW POWER MICRO CTD SELF-RECORDING CAPABILITY - FAST SAMPLING RATE: 8Hz DISSOLVED OXYGEN - ARCTICA, ANTARCTICA - BRINE - ROVs and AUVs

Product literature - Brochure

The OCEAN SEVEN 304 CTD, completes the line of high quality and accuracy IDRONAUT OCEAN SEVEN CTDs, fulfilling the demand for a high performance CTD probe with very small diameter and extremely low power consumption. This CTD can be easily integrated/adapted to third-party systems like floating profilers and/or buoy-moored systems, ROVs and AUVs. The 304 CTD standard interface is RS232C; other interfaces like: TTL, RS422 and Wireless Bluetooth® can be optionally installed. Idronaut prides itself on the design of its full ocean depth, pump free, low maintenance sensors. Central to which, is their high accuracy seven-platinum-ring quartz conductivity cell (patented), which can be cleaned in the field without the need for re-calibration. This unique quartz cell employs a large diameter (8 mm) and a short length (46 mm) to guarantee self-flushing and no clogging after long-term deployment even in biologically active waters. Competitors' cells, which present few mm only of cell orifice and very long cell length, are prone to clog even if protected by dangerous and poisonous antifouling devices. The OCEAN SEVEN 304 CTD does not require pumps or any other external device to flush the sensors, which minimizes its power consumption and allows the use in Arctica and Antarctica. The 304 CTD offers a combination of 16-bit high resolution data accuracy, with long-term sensor stability, making this CTD the best choice for both on-line profiling and self-recording moored applications. The CTD uses state-of-the-art electronics and is equipped with a 512-Mbyte logging memory. Moreover, the user can select the proper conductivity range: for salt or fresh water, making this CTD a very advanced tool for sampling sites near shore influenced by fresh water inlets, or/and for groundwater profiling and monitoring applications.

SAMPLING MODES User selectable sampling/operating modes include: Continuous: Data is sampled at configurable sampling rates starting from 0.1 Hz to 8 Hz. Sampling continues until interrupted. Multiple cycles can be obtained by switching the CTD ON and OFF. Pressure: Data is sampled at regular pressure intervals. Multiple profiles can be obtained by switching the CTD ON and OFF. Two different methods (conductivity or pressure) can be used to interrupt acquisitions when the CTD returns to the surface. This data acquisition method is ideal for profiling. Timed: CTD collects a series of samples and then sleeps for the configured time interval before waking up again and repeating the acquisitions. Time interval can be configured from 2 s up to 1 day. Battery power is conserved while the probe is in sleep mode. This data acquisition method is ideal for long-term monitoring. Conditioned: Data is sampled at configured sampling rates starting when the selected parameter overcomes the configured boundary. Sampling continues until the selected parameter falls below the configured boundary. Parameters used to condition the sampling can be: pressure, temperature and conductivity. Whenever the acquisition cycle starts, the CTD uses the same rules as the "Continuous" data acquisition. Monitoring of the selected parameter occurs at the configured interval. Burst: 8 Hz measurements can be performed at configured time intervals from 1s up to 1 day. Battery power is conserved by switching off the probe between bursts. REAL-TIME COMMUNICATIONS The OCEAN SEVEN 304 CTD communicates with a computer via a standard RS232C interface. Real-time data can be acquired by means of the REDAS Windows software. An optional RS422 interface overcomes the limitation of the RS232C cable maximum length (200 m) and allows the probe to transmit data through distances up to 1000 m. The communication speed is user selectable among: 9600, 19200, 38400 and 57600 bps. A Bluetooth® wireless interface can be optionally added to the wired interfaces. SOFTWARE Idronaut programmes operating under Windows 2K, XP, VISTA and Windows 7 allow the operator to configure the OCEAN SEVEN 304 CTD data acquisition and logger functions and upload data from the 512-MByte internal memory. They are: ITERM: terminal emulation programme to easily communicate with the OCEAN SEVEN 304 CTD using the probe integrated operator interface. REDAS: data processing and retrieval programme which allows the display and plotting of conductivity, temperature, pressure and derived variables such as salinity, sound speed, density, according to UNESCO formulas and recommendations.

TECHNOLOGY IN SEARCH OF NEW DEPTHS

DATA STORAGE AND BATTERY ENDURANCE
The OCEAN SEVEN 304 CTD allows the storing of 4,100,000 data sets each one being composed of the reading of: CTD sensors plus the acquisition date and time. The 304 CTD is powered by two PP3 9V alkaline batteries connected in parallel which provide 1 A/h sufficient to keep the CTD continuously ON for 36 hours in continuous sampling mode and at the maximum sampling rate. Further battery endurance can be obtained by using lithium batteries. Whenever the CTD operates in "Timed, Burst and Conditioned" modes, the battery endurance is considerably extended because the CTD waits for the interval between acquisitions in "Sleep mode".

CTD CHAINS

Chains of OCEAN SEVEN 304 CTDs are deployed by easily clamping the CTDs with a screwdriver to a rope (see picture). Chains of OS304 CTDs can be used to profile or perform long-term monitoring by properly configuring the CTD data acquisition method. Furthermore, the Bluetooth® wireless connectivity option allows the instant recovery of data stored in the CTDs internal memory once they are back to the surface. OS304 CTD Bluetooth® unique addressing identification code allows the operator to select one OS304 among the others present in the chain.

Set of 304 CTDs ready to be clamped on a rope

SENSOR SPECIFICATIONS
The OS 304 CTD can be equipped with the following sensors to measure:


OPTIONAL SENSOR SPECIFICATIONS
The OS304 CTD can be optionally equipped with the Highly Precise (0.01%FS) Pressure Sensor(1), IDRONAUT OEM Seapoint Turbidity Meter and oxygen sensor.

ELECTRONIC SPECIFICATIONS:
Real-time and logging: Interfaces: Baud Rate: Data memory: A/D converter: Supply Current        Running        Sleep: Communication protocol: Operator interface: Batteries:	8Hz. RS232C, Asynchronous TTL (0..5VDC), RS422, Bluetooth®. up to 57600 bps (9600 bps default). 512 Mbytes. 16-bit successive approximation, 4 multiplexed analogue inputs. 23 mA 4.5..11V, nominal 9V. 70 µA @ 9V. proprietary byte oriented binary and plain message protocol. friendly menu driven user interface. two 9V, 0.5 Ah, PP3 alkaline batteries connected in parallel.

PHYSICAL CHARACTERISTICS:
Housing:	1000 dbar (AISI 316/black POM)	1500 dbar (Titanium GR2)	6000 dbar (Titanium GR 5)
Dimensions:       housing diameter       total length Weight:       in air       in water	43mm 515mm 1.3 kg 0.7 kg	44mm 515mm 1.3 kg 0.7 kg	52 mm 532mm 2.7 kg 1.7 kg