OBS-3+

Turbidity Sensor

The OBS-3+ Turbidity Monitor is a submersible probe, part of our OBS® line of products that use a backscatter method to measure turbidity. The OBS-3+ operates in the range of 0 to 4000 NTU. It replaces the OBS3 on our price lists.

The OBS-3+ can be used in several applications, ranging from water quality in freshwater rivers and streams to sediment transport and dredge monitoring. The output for the OBS-3+ can be specified at time of order, allowing you to customize the sensor to match the datalogger being used to make the measurement.


Features

Each OBS-3 has two channels—one channel measures the lower turbidity range and the other channel measures the higher turbidity range.

-2.5

Supports our CR200-series, CR510, or CR10(X) dataloggers. Both channels have an output range of 0 to 2.5 V.

-5

Supports our CR800, CR850, CR1000, CR3000, CR5000, and CR9000(X) dataloggers. Both channels have an output range of 0 to 5 V.

-20

One channel has an output range of 4-20 mA, and the other channel has an output range of 0 to 5 V. A CURS100 is required for our dataloggers to read the 4-20 mA output.

Specifications

  • Accuracy of turbidity: 2% of reading or 0.5 NTU (whichever is greater)
  • Drift: less than 2% per year
  • Input voltage 5 to 15 Vdc (voltage); current output 9 to 15 Vdc (4-20 mA)
  • Maximum depth: 500 m with stainless-steel body; 1500 m with titanium body
  • Infrared wavelength: 850 nm ±5 nm
  • Length: 141 mm (5.56 in.)
  • Outer Diameter: 25 mm (0.98 in.)
  • Weight: 0.4 lb (181.4 g)
  • Optical power: 2000 µW