OBS-3A

• Maximum Depth: 300 m (984 ft)
• Connector: MCBH-8-FS, wet-pluggable
• Operating Temperature: 0° to 35°C
• Storage Temperature: -20° to 70°C
• Diameter: 7.6 cm (3.0 in.)
• Length: 36.2 cm (14.3 in.)
• Weight: 1.5 kg (3.4 lb)
• Drift Over Time: < 2% per year
• Drift Over Temperature: 0.05% per °C
• Maximum Sample Size: 2048
• Sampling Rate: 1 to 25 Hz
• Maximum Data Rate: 2 Hz
• Data Capacity: 8 MB
• Maximum Number of Data Lines: 200,000
• PC Interfaces: RS-232/115 kbps, RS-485/115 kbps
• Battery Capacity: 18 Ahr
• Maximum Battery Life: 8,000 hrs
• Infrared Wavelength: 850 nm

Measurement Ranges

• Turbidity: 0.4 to 4,000 NTU
• Concentration^a
  Mud^b: 0.4 to 5,000 mg/l
  Sand^c: 2 to 100,000 mg/l
• Pressure: 0 to 10, 20, 50, 100, or 200 m
• Temperature: 0° to 35°C
• Conductivity: 0 to 65 mS/cm
  (40 PSU, o/oo)

Accuracy

• Turbidity: < 2%
• Concentration^a
  Mud^b: 2% of reading
  Sand^c: 3.5% of reading
• Pressure: ±0.5% of f.s. (where f.s. = 50, 100, or 200 dBar)
• Temperature: ±0.5°C
• Conductivity: 1%

a - Concentration measurement range and accuracy depends on the sediment type.

b - Mud is defined as D₅₀ = 20 μm.

c - Sand is defined as D₅₀ = 250 μm.