4690 low range turbidity (sensor only)

The measurement of turbidity is a critical measurement in drinking water as it is used to indicate water quality and filtration effectiveness (for example, whether disease-causing organisms are present).

ABB's 4690 turbidity sensor paired with the AWT420 transmitter, has been designed specifically for the measurement of turbidity throughout the potable water treatment process.




Whichever of the two measurement ranges you choose, low range (0 to 40 NTU) or higher range (0 to 400 NTU), you can benefit from reliable, accurate turbidity measurement with automatic optical cleaning and dry standard calibration verification.


  • Flow-through turbidity design
    – Fast response to process turbidity changes due to minimal sample residence time
    – Compliant to ISO Method 7027
  • Automatic sensor cleaning
    – Reduces maintenance requirements
    – Optimizes performance sensitivity
  • Secondary standards for calibration verification
    – Accurate, repeatable, safe, simple
    – Realize significant cost savings by reducing the use of primary standards
  • Simple to use and maintain
    – Intuitive, user-friendly design
    – Simple-to-perform annual service
  • Reliable and accurate measurement
    – Ultralow back scatter for accurate measurement of low turbidity values
    – Automatic bubble rejection to compensate for erroneous readings due to degassing


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