Ultraviolet Transmission

UVT - Ultraviolet Transmission

UVT (Ultraviolet transmission) is a water quality parameter. The UVT method measures the amount of UV light at 254 nm, that is a simple ratio of the output light(I₁ from a sample and the input light(Io) and is normally written as a percentage:

UVT = I₁ / Io x 100%

In very clean water such as deionised water the UVT will be 100%, as there is no organic matter to absorb light at 254nm.

In untreated inlet water at a water treatment plant, you would see significant lower UVT value. This corresponds to the amount of treatment required.

See our UVT products
A modern UV254 Chemical Oxygen demand analyser

UVT Benefits

Learn more about what we do

• Measurement every 10 secs

• Measure source water in real time

 • UVT Data for site optimisation

• Savings on chemicals

• Savings on electricity
• Ensure quality by measuring final effluent  UVT
• Regulatory compliance

Inline UVT Monitoring

WTP UVT Applications

UVT in Water treatment plants

• Control of UV disinfection treatment, reducing power costs

 • Detection of load changes in water treatment influent

• Determination of organic loads in rivers and lakes

• WTP optimisation


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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