Print version Current manual - RS-232 or RS-485 (older manuals) Reference Sheet - RS-232 or RS-485 Configuration options & accessories
Intended for deployment in orientation shown (connector
at bottom) for
The SBE 37-SIP MicroCAT is a high-accuracy conductivity and temperature (pressure optional) sensor with Serial Interface and integral Pump, which includes a non-volatile memory. Externally powered, it is intended for moorings or other long-duration, fixed-site deployments. Constructed of titanium and other non-corroding materials to ensure long life with minimum maintenance, the MicroCAT's depth capability is 7000 meters (23,000 feet); it is also available with an optional 250-meter plastic ShallowCAT housing.
Calibration coefficients are stored in EEPROM, providing data output in ASCII engineering units (decimal or XML format); raw output is also available. The data always includes Conductivity, Temperature, and Pressure (if optional pressure sensor is installed); users can choose to add time, sound velocity (Chen-Millero), salinity, depth, and/or density.
SENSORS AND SENSOR INTERFACE ELECTRONICS
The MicroCAT retains the temperature and conductivity sensors used in our time-proven SeaCAT and SeaCAT plus products. Electrical isolation of the conductivity electronics eliminates any possibility of ground-loop noise. The MicroCAT’s unique internal-field conductivity cell permits the use of expendable anti-foulant devices. The aged and pressure-protected thermistor has a long history of exceptional accuracy and stability.
The optional strain-gauge pressure sensor is available in eight ranges, from 0 - 20 meters to 0 - 7000 meters. Compensation of the temperature influence on pressure offset and scale is performed by the MicroCAT’s CPU.
Temperature is acquired by applying an AC excitation to a hermetically sealed VISHAY reference resistor and an ultra-stable aged thermistor (drift rate typically < 0.002 °C per year). The thermistor resistance to reference resistance ratio is determined by a 24-bit A/D converter, which also processes the pressure sensor signal. Conductivity is acquired with an ultra-precision Wien-Bridge oscillator.
The integral pump typically runs for 1.0 second each time the MicroCAT samples, providing the following advantages:
COMMUNICATIONS AND INTERFACING
The MicroCAT communicates via standard RS-232 serial interface. Real-time data can be transmitted up to 1600 meters (5200 feet) at 600 baud (power considerations may limit distance), simultaneous with recording. Data can be uploaded at up to 115.2K baud. Firmware upgrades can be downloaded through the communications port, without opening the instrument. An optional RS-485 interface allows multiple MicroCATs to share a common 4-wire cable (power, common, data +, data -), minimizing cable complexity for C-T chains.
User-selectable operating modes include:
- Continuous sampling at the fastest rate possible (0.9 second minimum without pressure), with the pump running continuously
- Interval sampling at intervals of 6 seconds to 6 hours, with the pump running before each sample.
The MicroCAT is supplied with a powerful Windows 2000/XP software package, Seasoft© V2, which includes:
to 7 S/m
(0 to 70 mS/cm)
|-5 to 35||0.002||0.0002 per month||0.0001|
20 / 100 / 350 /
1000 / 2000 / 3500 / 7000 m
(meters of deployment depth capability)
|0.1% of full scale range||0.05% of full scale range per year||0.002% of full scale range|
Clock Stability: 5 seconds/month
Memory: 8 Mbyte; capacity in excess of 530,000 samples
Input Power: 0.25 Amps at 9 - 24 VDC
Quiescent Current: 30 microAmps *
Communication Current: 4.3 milliAmps *
Acquisition Current: 9.1 milliAmps (excluding pump) *
* Power consumption values are for standard RS-232 interface; for optional RS-485 interface, see RS-485 manual.
Acquisition Time: 0.9 - 2.7 seconds/sample, dependent on sampling mode and inclusion of pressure sensor
Pump Current: 25 milliAmps
Housing, Depth Rating, and Weight (without pressure sensor or clamps):
|Housing Material||Depth Rating||Weight|
|Standard||Titanium||7000 m (23,000 feet)||
3.0 kg (6.5 lbs) in
1.8 kg (64.0 lbs) in water
|Optional ShallowCAT||Plastic||250 m (820 ft)|
Dimensions: in millimeters (inches)
ADDITIONAL INFORMATION / LINKS:
Documentation -- manual, photos, technical papers, application notes, etc.
Sales Information -- options, accessories, cables, mount kits, spares, etc.
Software -- components of Seasoft V2
Links to Other Instruments of Interest
Specifications are subject to change without notice.
Sea-Bird Home Phone: (+1) 425-643-9866 Fax: (+1) 425-643-9954 E-mail: firstname.lastname@example.org