Walchem disinfection sensors

Non-Membrane Disinfection Sensor

Disinfection non membrane sensors, designed for high pressure, high temperature applications

Non-membrane chlorine/bromine and chlorine dioxide sensors comprising amperometric sensor assembly, cable, and a flow cell. They measure the disinfectant level in drinking water. The disinfection of hot potable water systems as currently required by the new ASHRAE standards is up to 70°C (158°F), especially for hospitals, schools, and universities.

Disinfection control

Cost effective and reliable solutions for disinfection control requirements. Compatible with the W100, W600, W900 and Intuition series controllers, the sensors continuously and directly measure the chlorine/bromine or chlorine dioxide chemical concentration without the use of reagents.

Amperometric sensors

Amperometric sensors perform best in drinking water or any clean water application with near neutral pH, and are typically used in higher pressure and/or temperature installations. Whether the application is a cooling tower, food and beverage, drinking water, wastewater, or swimming pool, these sensors provide stable, accurate measurements with low maintenance. Walchem controllers with amperometric chlorine sensors can be used for reporting chlorine residual measurements in accordance with EPA Method 334.0.


  • Free chlorine/bromine and chlorine dioxide sensors
  • Designed for higher pressure and temperature, clean water applications
  • Amperometric 3-electrode sensors
  • The measuring and counter electrodes are in direct contact with the sample
  • The reference electrode is isolated from the water by an electrolyte-filled housing



Key information

SensorMaterialpH rangeOperating temp
Free chlorine/bromine
5.00 - 9.00
0 to 50°C
Free chlorine/bromine
5.00 - 9.00
0 to 70°C
Chlorine dioxide
1.00 - 12.00
0 to 50°C
Chlorine dioxide
1.00 - 12.00
0 to 70°C

Operating pressure

0-4 bar - with polysulfone flow cell
0-8 bar - with acrylic flow cell



Typical applications

  • Hospitals
  • Schools
  • Universities
  • Swimming pools
  • Cooling towers
  • Food & beverage
  • Drinking water
  • Wastewater

NEW! Walchem disinfection flow cell

  • Pressure 0-4 bar
  • Material - polysulfone
  • Fraction of the price of previous matched design
  • Drop in replacement to older units
  • Accepts both metric & imperial tubing
  • Works with non-membrane disinfection sensors

Related products

  • Walchem disinfection sensors

    Membrane disinfection
    Cost effective & reliable amperometric disinfection sensors

  • Pyxis ST-500 Inline Sensor

    Bleach/chlorine dioxide
    Measure the optical density of bleach or chlorine dioxide

  • Pyxis ST-765ss Inline Sensor

    Oxidiser disinfection
    Measure free chlorine, chlorine dioxide or pH content in water

You may also need...

  • Intuition-9
    Powerful control with 24 inputs & 12 outputs

  • Intuition-6
    Remote communication with 4 inputs & 6 outputs

  • W100
    1 sensor input & 3 control outputs, wall mount design


  • Dosing tanks and bunds

    Dosing tanks & bunds
    Round or rectangular in a range of capacities from 25 to 1,000 litres.

  • Pyxis MA Series

    MA Series
    Inline BlueTooth® 5.0 wireless adapters

  • Pyxis MA Series

    Pyxis PowerPACK series BlueTooth® auxiliary adapters



Custom build solutions

Redefine simplicity and flexibility in cooling tower solutions with our plug-and-play service that delivers rapid installation.

We offer standard layout that serves as a solid foundation but we can be customise to meet the unique needs of any client site. We tailor the build to achieve optimal performance.

Our custom builds are popular as a comprehensive solution that's wired and seamlessly integrated meeting any site requirements. Email us today to learn more about our bespoke custom built solutions to speed up your installation and reduce operation or project downtime.


We specialise in delivering tailored product training to empower your team and enhance operational efficiency. Whether you prefer on-site sessions, at your company's location or the convenience of video conferencing, we've got you covered.

Our focus revolves around installation best practices, ensuring seamless product connectivity, and optimising maintenance procedures. Take the first step towards maximising your team's potential. Email us today to learn more about our bespoke training offerings, check availability, and embark on a journey to enhance your team's expertise.

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Sensys Ltd

Head Office
24 Vision Park
Preston Place
Upper Caldecote
SG18 9GQ

what3words: ///uptown.wisley.guests

01438 759 595

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