OBS-3A Turbidity and Temperature Monitoring System
5.1 Measurement Range
Turbidity (AMCO Clear):
0.4 to 4,000 NTU
1
Mud (D
50
=20 µm):
0.4 to 5,000 mg/L
Sand (D
50
=250 µm):
2 to 100,000 mg/L
Pressure
2
:
0 to 10, 20, 50, 100, or 200 m
Temperature:
0°
to
35°C
Conductivity (salinity):
0 to 65 mS/cm (40 PSU, o/oo)
1
0 to 100, 0 to 250, 0 to 500, 0 to 1000, 0 to 2000, and 0 to 4000 NTU
ranges are available.
2
Range depends on pressure sensor option chosen
.
5.2 Accuracy
Turbidity (AMCO Clear,
0 to 2,000 NTU):
<2.0%
Mud (0.4 to 4,000 mg/L):
2.0%
of
reading
Sand (0.4 to 60,000 mg/L):
3.5%
of
reading
Pressure:
±0.5% full scale
Temperature:
±0.5°C
Conductivity:
1%
5.3 OBS Sensor
Frequency:
5
Hz
Drift over time:
<2%
per
year
Drift over temperature:
0.05% per °C
5.4 Other Data
Maximum size sample:
2048
Sampling rate:
1 to 25 Hz
Maximum data rate:
25
Hz
Data capacity:
8
Mbytes
Maximum number
of data lines:
200,000
5
