SeapHOx - Deep Ocean CT(D)-pH-DO Sensor

The Sea-Bird Scientific Deep SeapHOx combines the Satlantic Deep SeaFET  pH sensor with the Sea-Bird Electronics SBE 37-SMP-ODO MicroCAT CTD+DO sensor. The Deep SeaFET adapts the MBARI/SIO/Honeywell Deep-Sea DuraFET technology to measure pH in a deep moored package. The Deep-Sea DuraFET technology was developed by Ken Johnson at MBARI and Todd Martz at SIO. The Deep SeapHOx allows for the integrated data collection of pH with the critical oceanographic and biological measurement of temperature, salinity, and oxygen. The integrated package also allows the SeaFET to take advantage of the SBE 37`s pumped flow path and anti-fouling technology, extending deployment durations in some cases.

Features

• Moored pH, Conductivity, Temperature, Pressure, and Optical Dissolved Oxygen, at user-programmable 5-minute to 24-hour intervals
• Integral pump
• RS-232 or USB interface
• Internal memory and batteries (can be powered externally)*
• Industry-leading conductivity cell biofouling protection
• SeaFETCom© Windows software package (setup, data upload, and data processing)
• Field-proven MicroCAT family, with more than 10,000 instruments deployed
• Maximum depth 2000 m
• * The instrument MUST carry internal batteries; external power may extend the deployment duration depending on the sampling regime.

Components

• pH sensor is an ion selective field effect transistor type adapted for high pressure operation
• Unique internal-field conductivity cell permits use of expendable anti-foulant devices, for long-term bio-fouling protection
• Aged and pressure-protected thermistor has a long history of exceptional accuracy and stability
• Strain-gauge pressure sensor with temperature compensation is available in 6 ranges
• Oxygen sensor is field-proven, individually calibrated SBE 63 Optical Dissolved Oxygen sensor
• Pump runs for each sample, providing improved pH, conductivity, and oxygen response, bio-fouling protection, and correlation of CTD and oxygen measurements

Options

• RS-232 or USB interface
• Wire mounting clamp and guide or brackets for mounting to a flat surface

Specifications

Measurement
Conductivity: 0 to 7 S/m (0 to 70 mS/cm)
Temperature: -5 to 45 °C
Pressure: 0 to 20 / 100 / 350 / 600 / 1000 / 2000 m (meters of deployment depth capability)
Dissolved Oxygen: 120% of surface saturation in all natural waters (fresh and salt)
pH: 6.5 - 9.0 pH

Initial Accuracy
Conductivity: ± 0.0003 S/m (0.003 mS/cm)
Temperature: ± 0.002 °C (-5 to to 35 °C); ± 0.01 °C (35 °C to 45 °C)
Pressure: ± 0.1% of full scale range
Dissolved Oxygen: larger of ± 3 μmol/kg (0.07 ml/L, 0.1 mg/L) or ± 2%
pH: 0.02 pH

Typical Stability
Conductivity: 0.0003 S/m (0.003 mS/cm) per month
Temperature: 0.0002 °C per month
Pressure: 0.05% of full scale range per year
Dissolved Oxygen: sample-based drift < 1 μmol/kg/100,000 samples (20 °C)
pH: 0.003 pH/month

Resolution
Conductivity: 0.00001 S/m (0.0001 mS/cm)
Temperature: 0.0001 °C
Pressure: 0.002% of full scale range
Dissolved Oxygen: 0.2 μmol/kg
pH: 0.004 pH

Miscellaneous
Memory Capacity: 4 GB
System Depth Rating: 2000 m
System Dimensions:

55.88 cm x 28.25 cm x 12.90 cm (Height does not include 3.56 cm end cap)
22" x 11.12" x 5.08" (Height does not include 1.4" end cap)