What is UVT?

Ultraviolet Transmittance (UVT), UV254 

UV Transmittance (UVT), also known as UV Transmission is the percentage of UV light transmitted through a sample of water. UV light exists below visible light in the colour spectrum, it can see particles in water which are invisible to the human eye. UVT (%) is used to detect organic material and contamination in water.

UVT monitoring provides quick and reliable results, making it valuable in various applications, including Water Treatment Plants (WTP), Wastewater Treatment Plants (WwTP), and Trade Effluent quality assessment. By implementing UVT monitoring, operators gain access to continuous real-time data that can be integrated into SCADA systems or accessed through a user-friendly IoT (Internet of Things) web portal.

This continuous stream of UVT data enables operators to closely monitor water quality, detect changes or anomalies, and make well-informed decisions regarding treatment processes. It enhances operational efficiency, helps ensure compliance with regulatory standards, and optimizes water treatment operations.

At Photonic Measurements, we have extensive expertise in UV254 technology, allowing us to provide reliable solutions for efficient and accurate water quality assessment across various industries. UVT monitoring allows our clients to achieve enhanced control, streamlined operations, and the delivery of high-quality water resources.

Our UVT monitoring solutions report both UVT and UV Absorbance parameters, providing a magnified insight to understanding of water composition. These results enable the identification of various parameters related to organic material. With our user-friendly interface and dependable probes, our clients enjoy an exceptional user experience and gain valuable insights from data trends.

The image below shows UVT Data presented on our IoT portal.  

A modern UV254 Chemical Oxygen demand analyser

Using UVT

Firstly set a baseline reference using deionised water this will allow full transmission of light and set this point as 100% transmittance, the probe will automatically set the 0 point of 0% UVT. This gives the 0 - 100% range of UVT. 

Allow sample water to flow through the flow cell crossing the measurement path. This can also be done using  quartz cuvette cell on the UV254 Go!

The results will be displayed on your controller. The results can be integrated into your plants SCADA system. This allows plant operators to use the UVT as a control measurement for treatment dosing.

Inline UVT Monitoring

Applications of UVT

UVT Monitoring is used in Water Treatment Plants (WTP) , Wastewater Plants (WwTP), Industrial Trade Effluent and Environmental Monitoring.

It can be used at raw water inlet, monitoring incoming water quality for feed forward maintenance.

A UVT analyzer can be used at final effluent to monitor discharges, report spikes, and to ensure compliance with environmental directives.

Combined Sewer Overflow (CSO) event duration and quality monitoring is another application.

UVT can be used at UV disinfection to check integrity of the system or for adjusting UV dose for efficiency.

It can help determine the organic loads in rivers and lakes.

UV Transmittances is a great tool to help optimise your Water Treatment Plant (WTP)


Lisburn BT28 2GN, GB

About us

Photonic Measurements is:
Incorporated in N.Ireland (NI622996) 
VAT registered in UK (GB192976846)
VAT registered in N.Ireland (XI192976846000)

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