Pyxis ST-600

Measuress the real-time mass/mass concentration of bleach (sodium hypochlorite) at a range of 0–16%

ST-600 series inline probes directly measure the optical density of the bleach or chlorine dioxide solution in percentage (%) levels without dilution using a UV light source. The ST-600 series probes have a built-in reference light source and a reference light detector in addition to the main light source and main light detector. This configuration ensures a long-term stable measurement of the disinfectant concentration.


  • Break-through technology measures disinfection liquids from low to high concentration
  • Direct read technology without dilution or reagent.
  • Long maintenance and calibration cycle – 6 months typical.
  • Convenient 3⁄4” NPT inline tee installation (ST-001) for large pump suction side
  • Convenient 1⁄4” teflon tubing installation for small pump discharge side
  • Probe cleanliness diagnostics via uPyxis and Modbus
  • Wireless calibration via uPyxis mobile or desktop app
  • Expanded concentration range
  • Temperature compensation (RTD) of oxidant concentration and temperature output signal


Product range

% Chlorine in Bleach
Liquid Concentrate
0.01–16.0% mass/mass
% ClO2 in Bleach
Produced ClO2 Solution
0.01–0.35% mass/mass
% Chlorine in Bleach
Electrolysis Effluent
0.01–2.00% mass/mass
Sensors: Teflon tubing
Low volume flow
Low cost CPCC contacting sensor
ST-100: Optional tee
High volume flow
Low cost CPCC contacting sensor

Typical applications

Built for industrial cooling water and process treatment applications.

Related products

  • Walchem disinfection sensors

    Non-membrane disinfection
    For high pressure, high temperature applications

  • Walchem disinfection sensors

    Membrane disinfection
    Cost effective & reliable amperometric disinfection sensors

  • Pyxis ST-765ss Inline Sensor

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

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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

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01438 759 595

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