OBS501 Turbidity Probe with Antifouling



The OBS501 combines a backscatter sensor (better at measuring high turbidity) with a second sidescatter sensor (better at measuring lower turbidity). This SDI-12 probe uses digital processing.

The OBS501 incorporates the ClearSensor® Antifouling Method to ensure the accuracy of its measurements. The ClearSensor® method uses a shutter/wiper mechanism to protect and clean the optics. This antifouling method also includes a chamber filled with a biocide that continuously leaches out over the optics while the probe is in the closed position.

The OBS501 includes a disposable plastic sleeve that can make clean up a snap, as well as an optional copper sleeve that can provide additional protection, especially in sea water.


Dual backscatter and sidescatter sensors used to measure turbidity
ClearSensor® Antifouling Method for better measurements in biologically-active water
Shutter/wiper mechanism keeps lenses clean
Refillable biocide chamber prevents fouling
Disposable plastic sleeve facilitates clean up
Optional copper sleeve for additional protection, or disposable plastic sleeve facilitates easy cleanup
SDI-12 and 5V outputs

Technical Specifications

Dual Probe: 90° side scatter and backscatter
Range: 0 to 4000 NTU
Active & Passive Antifouling: shutter, wiper, biocide, copper, optional removable sleeve
Accuracy: ±2% of reading or 0.5 NTU (which ever is greater)
Temperature Range: 0° to 40°C
Temperature Accuracy: ±0.3°C
Emitter Wavelength: 850 nm
Power Requirements: 9.6 to 18 Vdc
Power Consumption
Quiescent: <200 µA
Measurement: <40 mA
Communication : <40 mA
Maximum Peak Current: 200 mA for 50 ms when shutter motor starts
Active Shutter Motor: <120 mA
Measurement Time: <10 s Outputs: SDI-12 (version 1.3) 1200 bps;RS-232 9600 bps;Analog 0 to 5 Vdc Max. Submersion Depth: 100 m (330 ft) Dimensions Diameter: 4.8 cm (1.88 in.) Length: 27 cm (10.63 in.) Weight: 0.59 kg (1.30 lb) Maximum Cable Length: > 500 m (1640 ft)

Data Sheet

OBS 501