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MicroCAT C-T-ODO (P optional) Recorder
SBE 37-SMP-ODO (Serial interface, Memory, integral Pump, & integrated Optical Dissolved Oxygen)

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Print version     Current manual - RS-232, RS-485, SDI-12 (older manuals)   Reference Sheet - RS-232, RS-485, SDI-12     Configuration options & accessories

Plastic housing; titanium housing also available.
 SBE 37 MicroCAT CTD and Optical Dissolved Oxygen Moored Recorder
Deploy in orientation shown (connector end down) for proper operation.

SUMMARY

DESCRIPTION

The SBE 37-SMP-ODO MicroCAT is a high-accuracy conductivity and temperature (pressure optional) recorder with Serial interface, internal batteries, Memory, integral Pump, and Optical Dissolved Oxygen sensor. The MicroCAT is designed for moorings or other long duration, fixed-site deployments. Constructed of non-corroding materials to ensure long life with minimum maintenance, it is rated for operation to 350 meters (plastic ShallowCAT housing) or 7000 meters, or pressure sensor full-scale range.

Calibration coefficients are stored in EEPROM, allowing output of C, T, (optional) P, DO, and time in ASCII engineering units (decimal or XML; raw output available); salinity, sound velocity, and specific conductivity can also be output.

SENSORS

Conductivity and Temperature sensors are based on our field-proven SeaCAT and SeaCATplus. Electrical isolation of conductivity electronics eliminates any possibility of ground-loop noise. Our unique internal-field conductivity cell permits the use of expendable anti-foulant devices, for long-term bio-fouling protection. The aged and pressure-protected thermistor has a long history of exceptional accuracy and stability.

The oxygen sensor is our field-proven SBE 63 Optical Dissolved Oxygen sensor.

The optional strain-gauge pressure sensor is available in eight ranges, to a maximum depth of 7000 meters. Compensation of the temperature influence on pressure is performed by the MicroCAT’s CPU.

PUMP

The integral pump runs each time the MicroCAT samples, providing the following advantages:

With Adaptive Pump Control, the MicroCAT calculates the pumping time for best oxygen accuracy as a function of the previous sample's temperature and pressure (maximizing data quality while minimizing power consumption).

COMMUNICATIONS AND INTERFACING

The MicroCAT communicates via one of the following interfaces:

User-selectable operating modes include:

SOFTWARE

The MicroCAT is supplied with a powerful Windows software package, Seasoft© V2, which includes:

DATA STORAGE AND BATTERY ENDURANCE

Temperature and conductivity are stored 6 bytes/sample, time 4 bytes/sample, oxygen 6 bytes/sample, and optional pressure 5 bytes/sample; memory capacity exceeds 380,000 samples (with pressure). The MicroCAT is powered by a 7.8 Amp-hour (nominal) battery pack with twelve AA lithium cells (Saft LS14500) which, when removed from the MicroCAT, can be shipped via commercial aircraft. Battery endurance varies widely, depending on the sampling scheme and deployment pressure and temperature. Sampling every 10 minutes in water temperatures of approximately 10 C, the MicroCAT can be deployed for almost 6 months (24,000 samples); see the manuals for example calculations.

SPECIFICATIONS

  Measurement
Range		 Initial
Accuracy		 Typical
Stability		 Resolution
Conductivity 0 to 7 S/m
(0 to 70 mS/cm)		 ± 0.0003 S/m 
(0.003 mS/cm)		 0.0003 S/m
(0.003 mS/cm)
per month		 0.00001 S/m
(0.0001 mS/cm)
Temperature
 (°C)		 -5 to 45 ± 0.002 (-5 to 35 °C);
± 0.01 (35 to 45 °C)		 0.0002 per month 0.0001
Optional Pressure 20 / 100 / 350 / 600 / 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
Oxygen 120% of surface saturation in all
natural waters (fresh and salt)		 larger of ±3 µmol/kg
(equivalent to 0.07 ml/L or 0.1 mg/L)
or ±2%		 sample-based drift <
1 µmol/kg/100,000 samples (20 °C)		 0.2 µmol/kg
         

Clock Stability: 5 sec/month

Acquisition Time: 2.4 - 3.2 sec/sample, dependent on sampling mode and inclusion of pressure sensor (see manual)

Power Supply: 7.8 Amp-hour (nominal) battery pack, 257 KJoules (derated for calculations)

Optional External Power: 0.25 Amps at 9 - 24 VDC

Power Consumption (all with pressure) *:

   Quiescent: 0.0004 Watts

   CTD-DO Sample Acquisition (excluding pump): 
      Real-time data enabled - 0.17 Watts
      No real-time data - 0.155 Watts

   CTD-DO Sample Waiting (not sampling, pump running, excluding pump):
      Real-time data enabled - 0.056 Watts if receive line valid,
                                          0.016 Watts if receive line not valid
      No real-time data - 0.016 Watts

   CTD-DO Between Samples:
      Real-time data enabled - 0.056 Watts if receive line valid
                                          0.0004 Watts if receive line not valid
      No real-time data - 0.0004 Watts

   Pump: 0.12 Watts

   Communications: 0.065 Watts

* Power consumption values are for RS-232 interface; for other interfaces, see corresponding manual.

Housing, Depth Rating, Weight:

Housing Material Depth Rating Weight
Plastic 350 m (1150 ft) 3.4 kg (7.5 lbs) in air, 1.5 kg (3.3 lbs) in water
Titanium 7000 m (23,000 feet) 4.2 kg (9.2 lbs) in air, 2.3 kg (5.0 lbs) in water
     

Dimensions

       Note: 103 mm dimension is for plastic housing; titanium housing dome is 9 mm smaller

Connector:

RS-232 Interface
 (For RS-485: pin 2 is RS-485A, pin 3 is RS-485B)

SDI-12 / RS-232 Interface

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

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Specifications are subject to change without notice.

Sea-Bird Home     Phone: (+1) 425-643-9866     E-mail: seabird@seabird.com