New Endress+Hauser Turbimax CUS51D Turbidity Sensor CUS51D-AAD1A3

What is it

The Turbimax CUS51D is a smart sensor for measuring turbidity and suspended solids in liquids, intended especially for water, wastewater, and related industrial or utility uses.

It uses Memosens digital signal technology, meaning the sensor itself has digital communication and calibration/data integrity built in.

Measuring principle

• It uses scattered light methods: both 90° and 135° scattering from particles in the medium.
• It also includes a four-beam pulsed light system: two light sources + four receivers. Pulsed light helps reduce interference, improve signal quality, and compensate for fouling or window soiling.
• Depending on the turbidity / solids concentration, it switches among different built-in models (pre-calibrated analytical models) to adapt to low, medium, or high solids / turbidity.

Key features & benefits

• Wide measurement range:
• For form­azine (standard turbidity standard): 0 to 4000 FNU (with display range up to 9999 FNU)
• For sludge / high solids: up to ~ 300 g/L (depending on medium)
• Robust & low maintenance:
• Self-cleaning options (air cleaning)
• Optical windows made of sapphire; housing in stainless steel (316L etc.)
• Protection: IP68 for immersion (1 m water column for 60 days in 1N KCl)
• Digital, pre-calibrated:
• Comes factory calibrated for form-azine; has multiple pre-calibrated application models (kaolin, sludge etc.) to simplify commissioning.
• Allows calibration up to 5 points, either in lab or in-situ.
• Flexible installation:
• Can be installed in situ (immersion), in retractable holders, or via sample/flow cell setups.
• Different process connection standards (G1, NPT ¾″)

Technical specifications (summary)

Typical applications

• Wastewater treatment: measuring solids in activated sludge basins, recirculation, sludge handling.
• Drinking and process water: turbidity monitoring, flocculent dosing.
• Utility / industrial effluents: tracking solids content, monitoring filtration, etc.