Ultraviolet Transmission (UVT)

Ultraviolet Transmission (UVT) is a relative measurement comparing how much light passes through a water sample vs a pure water  sample at 254nm expressed at a 1cm path length. This measurement is used for UV control to allow energy savings by adjusting the output to match water quality and flow in real-time. This avoids over dosage and reduces overall operating cost without compromising disinfection performance.

For long-term, in-situ continuous monitoring of ultraviolet transmission, a self-cleaning UVT sensor is usually necessary to avoid fouling of the sensor and maintain accuracy. Xylem | WTW products use ultrasonic cleaning to extend deployments and include many advanced features such as real-time turbidity compensation to provide the best quality real-time measurement in difficult applications.

  • Online
  • Laboratory
  • Portable

WTW IQ SensorNet 282

Controller for small and mid-sized wastewater treatment plants including USB-interface and internal data logger – up to 4 sensors, all parameters, available anytime.

2020 3G family

WTW IQ SensorNet 2020 3G Controller

With an easily scalable solution, the 2020 3G allows for the connection of up to 20 sensors. This modular plug-and-play system allows you to monitor the water quality in your wastewater system continuously and accurately.



The SAC sensor measures Spectral Absorption Coefficient (SAC) and UV transmission (UVT) at 254nm for determination of organic loads in water. With the  sensor UV 700 IQ SAC this parameter can be detected directly without any chemicals. A reference measurement is performed for compensation of turbidity influences.

Alt: WTW photoLab® 7600 UV-VIS

WTW photoLab® 7000 Series Spectrophotometer

The photoLab® 7000 series of spectrophotometers combine latest optical technology with digital processing to provide users with an efficient and effective means of gathering spectrophotometric data in chemical, pharmaceutical, food, beverage and especially environmental applications.   Special software features include up to 200 industry standard scales/methods and the unique OptRF feature for determining nitrate and nitrate without the need for reagents. Additionally, photoLab Data software expands its capability by displaying results in industry standard color scales including CIE, EBC, ASTM, ICUMSA and so on.