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GENERAL OCEANICS |
Specifications data for the Ocean Seven Model 301 Coastal CTD
The measurement sensors (see table for SENSOR SPECIFICATIONS) installed in the OCEAN SEVEN 301 Probe are exported all over the world. They are used by several other multiparameter probe manufacturers. All sensors have extremely low time constants: 50 milliseconds for physical parameters (CTD) and 3 seconds for chemical parameters (DO, pH).
The OCEAN SEVEN 301 Probe is microprocessor-controlled and can measure, store and transmit sensor data according to various methods. The most significant ones are: real-time data acquisition which implies acquisition and transmission of data to a Personal Computer; timed data acquisition which enables the user to automatically acquire and store sensor data at a configurable time interval (from 1 tenth of second to 24 hours). In the latter case, the Probe can work unattended and data can be uploaded at the end of the measuring cycle. Enhancing of the internal battery endurance is obtained through an automatic power management procedure that switches OFF the probe between data acquisitions. The internal battery package consists of ten batteries: 1.5 V, 1.8 A/h, AA cell which allow a continuous probe operation for about 22 hours. Rechargeable or lithium batteries can be used alternatively. The probe is equipped with an internal non volatile SRAM able to store up to a maximum of 6665 data sets (27300 with the memory expansion option), each data set being composed of the measuring date and time and of the seven (7) standard sensors (see SENSORS SPECIFICATIONS).
The OCEAN SEVEN 301 Probe can be equipped with an external battery package which greatly extends the probe operation.
The OCEAN SEVEN 301 Probe can be configured to be directly connected to a Personal Computer by means of: the RS232C serial interface or the telemetry interface (see the Telemetry system performance chart). The telemetry interface remedies the limitations of the RS232C serial interface (cable length and number of conductors).
When using the FSK or ASK telemetry interface, the additional deck unit (PORTABLE DECK UNIT) is required to convert serial, RS232C type signals (coming from a PC communication port), into telemetry signals (and vice versa) which must flow superimposed on the probe Power supply along the coaxial armored single conductor probe cable. The armored cable supports the probe mechanically.
The following chart resumes the OCEAN SEVEN 301 Probe interfaces performances:
OCEAN SEVEN 301 Telemetry Systems Performance Chart
Telemetry Type Max cable length Max transfer rate
RS232C 100 meters 19200 bps
ASK 1500 meters 9600 bps
FSK 1500 meters 38400 bps
FSK 3000 meters 19200 bps
FSK 6000 meters 9600 bps
FSK 10000 meters 4800 bps
The above performances are obtained by using the 6.4 mm diameter Rochester cable 1-H-255 which has an electrical resistance of 23 W/km and a capacity of 138 pF/m.
The probe communication occurs by means of two male connectors installed in the probe top cover. A four pole connector is used for the RS232C interface, while, a two-pole connector is used for the telemetry interface and to power the probe.
With a Personal Computer equipped with the P301LINK software, it is possible to manage all operating functions of the OCEAN SEVEN 301 Probe, thus, enabling the user, for instance, to configure a measuring cycle, upload stored data, save them into an ASCII file and, when necessary, to perform sensors calibration.
The IDRODAC management software allows real-time data acquisition and shows data in numerical or graphic format. Data can be acquired by means of several data acquisition methods: manual (user selectable), linear (in relation to depth increase), timed (in relation to time interval).
The system is composed of:
A) OCEAN SEVEN 301 PROBE PROVIDED WITH ASK AND RS232C OUTPUTS, EQUIPPED WITH BUILT-IN DATA LOGGER AND BATTERIES
The unit contains:
- - the sensors;
- - the electronics for managing the sensors;
- - the electronics to digitally transform the measurement signals;
- - the memory unit;
- - the serial port to communicate with the personal computer via ASK= telemetry.
SENSORS:
The probe is equipped with the following standard sensors to measure:
PRESSURE
TEMPERATURE
CONDUCTIVITY
SALINITY
OXYGEN
pH
OXIDATION-REDUCTION POTENTIAL
Salinity is automatically calculated from conductivity, temperature and pressure values.
SENSOR SPECIFICATIONS:
Parameter Range Accuracy Resolution Time Constant
Pressure 0 - 1500 dbar* 0.25% F.S. 0.1 dbar 50 ms
Temperature -1 ... +50 0.01 0.004 50 ms
Conductivity 0..62 mS/cm** 0.02 mS/cm 0.004 mS/cm 50 ms +
Oxygen 0..50 ppm 0.1 ppm 0.01 ppm 3 s ++
0..500% sat. 1% sat. 0.1% sat. 3 s
pH 0..14 pH 0.05 pH 0.01 pH 3 s
Redox -1000 to +1000 mV 10 mV 1 mV 3 s
+ at 1 m/second flow rate
++ in air
* other standard pressure transducers available have 20, 70 and 300 dbar ranges.
** a probe version with conductivity range for fresh water is also available:
Range Accuracy Resolution Time Constant
0..6200uS/cm 2 uS/cm 0.4 uS/cm 50 ms +
PHYSICAL CHARACTERISTICS Plastic body Steel body
Dimensions: housing diameter: 100 mm 75 mm
total length: 710 mm 685 mm
Weight : in air: 6 kg 4 kg
in water: 3 kg 1,8 kg
Material: white PPS AISI 316
Diameter of protection cage: 260 mm, titanium
Cable connectors: 2-pole connector (Brantner RMG-2-FS) for ASK telemetry output;
4-pole connector (Brantner RMG-4-FS) for RS232C output.
Power supply: 10..30V, 70 mA @ 12 V, 850 mW power consumption
B) OPTIONAL OBS3 SENSOR FOR SUSPENDED SOLIDS AND TURBIDITY OBS3
is an optical sensor for measuring turbidity and suspended solids concentrations by detecting infrared (IR) radiation scattered from suspended matter. With its unique optical design, OBS sensors perform better than most in situ turbidity sensors in the following ways:
- - small size and sample volume;
- - linear response and wide dynamic range;
- - insensitivity to bubbles and organic matter,
- - ambient light rejections and low temperature coefficient
OBS3 sensor can be calibrated to measure turbidity or suspended solids directly.
OBS3 sensor consists of a high intensity infrared emitting diode (IRED), a detector (four photodiodes), and a linear, solid state temperature transducer. The IRED produces a beam with half-power points at 50o in the axial plane of the sensor and 30o in the radial plane. The detector integrates IR scattered between 140o and 160o. Visible light incident on the sensor is absorbed by a filter. Sensor components are potted in glass-filled polycarbonate with optical-grade epoxy. The OBS3 sensor is a "stand alone" version, with housing and connector.
A cable interfaces the OBS3 output with the OCEAN SEVEN Probe which provides the OBS3 data management and its power supply. A clamp holds the OBS3 with the OCEAN SEVEN Probe.
Range Turbidity: 0.02 2,000 FTU Mud: 0.1 5,000 mg/l Sand: 2 100,000 mg/l Frequency response: 10 Hz Physical dimensions: Sensor 51 (diam) x 180 mm Housing length 115 mm Housing diameter 31 mm Weight (air) 170 g Weight (submerged) 70 g Max working depth: 2000 metres
C) RS232C COMMUNICATION CABLE TO CONNECT THE 301 PROBE DIRECTLY WITH A PERSONAL COMPUTER
c.1) 8 mm POLYURETHANE FOUR-WIRE SHIELDED CABLE (Not armored) RS232C data transmission imitates this cable length to 50 meters.
c.2) CONNECTION KIT FOR RS232C CABLE Composed of a waterproof probe connector, a PC serial connector and a holding system for the probe.
D) TELEMETRY CABLE AND OPTIONAL WINCH
d.1) COAXIAL ARMORED CABLE A loading, 7 mm polyurethane coaxial armored cable. Breaking strength is 350 kg.
d.2) CONNECTION KIT FOR TELEMETRY CABLE Composed of a waterproof probe connector, a PORTABLE DECK UNIT connector and a holding system for the probe. Please note: for cable of more than 25 m length, it is advisable to use the optional manual winch provided with slip-ring.
d.3) OPTIONAL MANUAL PORTABLE WINCH Provided with: handle, waterproof Probe connector, a PORTABLE DECK UNIT connector, quick connection system for the Probe and slip-ring. Capacity: 180 meters of 7 mm cable.
E) PORTABLE DECK UNIT TO POWER AND INTERFACE, WITH TELEMETRY, THE 301 PROBE AND A PC
(Not needed if the probe operates with RS232C only). The unit enables the OCEAN SEVEN 301 Probe, which is set to transmit data with ASK modulation, to be interfaced with a Personal Computer. The coaxial armored cable is used for connection.
The unit includes:
- - power source for the OCEAN SEVEN 301 Probe;
- - modulation and demodulation circuits (ASK signals);
- - RS232C output for connection to the Personal Computer.
Power is by an internal battery (12V - 6.5 A/h) which is recharged when unit is connected to external 100, 110 or 220 V AC, 50/60 Hz source. The unit allows full operation of Probe for about 35 hours without AC power.
Dimensions: 275 x 250 x 75 mm. Weight: 4,5 kg.
Please note: In case the Portable Deck Unit is required, it is necessary that the coaxial armored cable (item d.1) with associated connector (item d.2) be ordered.
Otherwise, you can simply order the RS232C - 8 mm cable (item c.1) with the associated connector (item c.2). In the latter case, the 301 Probe will work with its internal batteries rather than the ones of the Portable Deck Unit.
F) SOFTWARE
f.1) SOFTWARE FOR DATA TRANSFER - P301LINK
The purpose of the P301LINK software is:
- to recover the memorized data via RS232C. The files are in ASCII delimited format;
- to programme the Probe main operating functions.
The software is to be installed in a personal computer with the MS-DOS operating system. The minimum hardware requirements are: VGA color monitor, 640 Kbytes RAM, DOS 3.0 or further version operating system, hard disk with 20 Mbytes at least, Epson compatible printer, one RS232C serial interface.
f.2) SOFTWARE FOR DATA TRANSFER AND MANAGEMENT - IDRODAC
The purpose of the IDRODAC software is to visualize, print and recover data received from the OCEAN SEVEN 301 Probe. The software allows the following data acquisition functions: manual profiles, linear profiles, timed profiles. The data on file can be transferred on the screen in numerical shape and can be printed and exported in ASCII file format. The software is to be installed on a personal computer with the MS-DOS operating system. The minimum hardware requirements are: CGA monitor, 640 Kbytes RAM, 2 floppy units. Anyhow, the use of a hard disk (20 Mbytes at least) and a VGA color monitor is recommended.
f.3) REAL-TIME GRAPHIC PRESENTATION SOFTWARE
This software extends operation of the above mentioned interface software. It allows creation of real time bidimensional plots on the basis of data acquired by the probe. Up to six parameters can be simultaneously plotted, in relation to depth or time. Plots can be also obtained by data already filed.
THIS OPTION CANNOT BE USED SEPARATELY BUT IT IS TO BE COUPLED WITH ITEM f.2).
