Turbidity Sensors and Transmitters

Turbidity Sensors and Transmitters

Turbidity sensors measure the cloudiness of a liquid caused by suspended particles and are commonly extended to quantify total and suspended solids in appropriate applications. A complete solution includes the sensor, transmitter, and installation method that maintains representative measurement while managing fouling, bubbles, and variable flow.

Turbidity measurement supports quality assurance and process control across drinking water production, effluent monitoring, and sludge concentration measurement in wastewater treatment. It is also used to monitor seawater inlets in desalination projects and to detect product losses in dairies where abrupt turbidity changes can indicate leakage or loss events with high economic impact.

Sensor selection depends strongly on the turbidity regime and the nature of the solids. Nephelometric sensors are applied to low-turbidity media such as potable water. For high turbidity (common in wastewater), suspended solids sensors are typically selected. Where turbidity fluctuates extremely and unambiguous results are required - such as reliable product loss detection - absorption-based approaches can be preferred to reduce ambiguity associated with scattering behavior.

Typical applications include filter performance monitoring, clarifier effluent quality tracking, membrane protection and breakthrough detection, sludge thickening and dewatering control, and intake monitoring where changes in raw water quality must be recognized quickly. Turbidity trends also help diagnose upstream disturbances and assess the effectiveness of coagulant/flocculant dosing strategies.

Engineering considerations include installation geometry (to minimize settling and bubble interference), cleaning strategy (manual, air, or mechanical wipers depending on the sensor design), and calibration approach aligned with the measurement method. When deployed as part of a broader monitoring suite, turbidity is often paired with pH, conductivity, oxygen, and nutrient signals to create a more complete picture of treatment performance and process stability.

George E. Booth Co., an exclusive authorized representative of sales and service for Endress+Hauser.