Our UV254 Probe is manufactured right here in Lisburn, N. Ireland. We provide probes for OEMs in the instrumentation market, as well as, supplying probes and systems to market ourselves.

UV254 Probe

A UV254 probe is a water quality monitoring device that measures UV Transmittance and UV Absorption at wavelength of 254 nanometres (nm) in a water sample, commonly used to quantify the concentration of organic matter and contaminants in water. 

UV254 probes are used for a variety of applications in the field of water quality management and environmental monitoring.

These probes can identify the presence of organic contaminants from industrial discharges, agricultural runoff or wastewater effluents. They are particular effective for measuring inlet water and identifying dosing requirements in a predictive manner.

By measuring UV Absorbance (Abs.) or UV Transadmittance (%) the probe helps detect organic pollutants that might affect water safety and environmental health.

The measurements and data gained from using UV254 probes can assess the quality of drinking water sources, such as rivers, lakes and reservoirs. Elevated UV254 levels can indicate the presence of Natural Organic Matter (NOMs) or contamination. 

UV254 probes are also used to monitor the efficiency of wastewater treatment processes by measuring and verifying final effluent. UV can also be used at drinking Water Treatment Plants (WTPs) at raw water inlet, clarifiers and post-processed water all in real time. A rise in UV254 absorbance can suggest incomplete removal of organic matter, providing insight into the treatment plant's performance.

The sensitivity of UV254 measurements helps users detect contaminants at an early stage, enabling timely intervention to prevent further pollution. Allowing for feed-forward processing and predictive maintenance and highlights the importance of data-driven decisions. UV254 data provides valuable insights for informed decision-making in water treatment processes, environmental management and helps to avoid nasty fines.

The main benefit to using an electronic probe is the data is received in near real-time, combined with our innovative controller you can take full control of how you receive your data and send signals back to your process from any location. Making you the master of your own water.

UV254 Sensor / Probe Benefits


• No consumables—no additional costs

•Long life LEDs

•No moving parts–minimal maintenance

• Ergonomically designed

• Turbidity compensation


• Titanium, stainless steel and aluminium options

• Low operating costs

 •No moving parts–minimal maintenance


•Measurements every ten seconds

•Real-time indication of BOD, COD, TOC and DOC surrogates*

• We store your reference measurement, no zeroing to DI water before each test

• Our device has 5 different measurement options with five different path lengths

• Continuous use LEDs for stability and long life, not mercury lamps

Easy installation

 •Modbus Interface for third party controllers

•Automated calibrations saved on the probe

•Complete system available

•Low energy consumption

• Flowcell option or insert in pipe

• Calibration saved on the probe


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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