Turbidity Sensors / OBS-3-L
RETIRED ›
This product is no longer available. Some accessories, replacement parts, or services may still be available.
OBS-3-L D&A Instrument Company Turbidity Monitor
Services Available
Repair No
Calibration No
Free Support No

Overview

The OBS-3 measured both turbidity and suspended solids. Its turbidity range was 0 to 4000 NTU. A nearly linear response to particle concentrations of turbidity spanned more than three orders of magnitude. (OBS® is a registered trademark of Campbell Scientific.)

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Specifications

  • Non-linearity of turbidity: 2% (formazin, 0 to 2000 FTU)
  • Drift: < 5% per year
  • Settling time: < 1 s
  • Input voltage: 9 to 16 Vdc
  • Maximum depth: 500 m (1640.5 ft)
  • Infrared wavelength: 875 nm
  • Diameter: 1.2" (3 cm)
  • Length: 7.1" (18 cm)
  • Weight: 0.4 lb (181.4 g)

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Dataloggers

Product Compatible Note
21X (retired)
CR10 (retired)
CR1000 (retired)
CR10X (retired)
CR200X (retired)
CR206X (retired)
CR211X (retired)
CR216X (retired)
CR23X (retired)
CR295X (retired)
CR3000 (retired)
CR500 (retired)
CR5000 (retired)
CR510 (retired)
CR800 (retired)
CR850 (retired)
CR9000 (retired)
CR9000X (retired)

Documents

Frequently Asked Questions

Number of FAQs related to OBS-3-L: 12

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  1. How does sediment concentration affect an OBS sensor?

    This application note shows sample calibrations for sand, silt, and clay.

  2. How do OBS and other optical sensors measure turbidity and suspended solids?

    This application note provides general information about sediment sensors, light sources and detectors, optical designs, applications, and turbidity standards.

  3. Does it matter how sediment calibration standards are prepared?

    Read this application note to learn more about the effect of drying and grinding sediment for calibration.

  4. Is fouling of OBS sensors something to be concerned about?

    This application note contains information regarding biological and chemical fouling.

  5. How is light transmitted through water samples?

    This application note provides an introduction to light absorption, scattering, and attenuation, as well as other optical properties that affect OBS sensors.

  6. Can NTUs be directly converted to SSC?

    Read this application note to learn about SSC turbidity relationships.

  7. How does sediment size affect an OBS sensor?

    The application note includes OBS response to sand, mud, and flocculants and results of tests by U.S. Navy Civil Engineering Laboratory.

  8. How big are the effects of sediment color on OBS measurements?

    This application note includes information on sediment color and NIR reflectivity.

  9. What light sources and detectors are used in OBS sensors?

    This application note provides a description of infrared-emitting diodes, laser diodes, photodiodes, daylight filters, and operating spectra.

  10. What turbidity standards should be used for calibrating OBS sensors?

    This application note includes a discussion of formazin and SVDB-microsphere turbidity standards.

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Casos de estudio

New Zealand: Coal Mine Water Quality Monitoring
High-grade coal has been mined on the West Coast of New Zealand since the 1870s.......read more
Southeastern U.S.: Sediment Production Study
D & A Instruments (now part of Campbell Scientific) assisted the USDA National Sedimentation Laboratory......read more
Explore All Case Studies