Pyxis ST-725 Inline Sensor

Pyxis ST-725 Inline Conductivity Sensor

The ST-725 is an industrial-grade, inline ultra-low conductivity sensor designed for pure & ultra-pure water applications.

These are ‘smart sensors’ with a built-in transmitter supporting digital & analog signal outputs, and are designed to simplify field installation, calibration and operation. The sensors offer simple 3/4” MNPT threaded installation and are constructed with a Hastelloy electrode tip & stainless-steel body. The ST-725 sensor can be wirelessly calibrated with uPyxis® app when used with the MA-CR Bluetooth® adapter. The sensors both offer (2) 4–20mA Analog outputs, one for conductivity and one for temperature, as well as RS-485 Modbus output for a broad array of installations that desire to connect the smart sensor directly to any receiving controller, PLC or DCS network. The ST-728 has a built-in RTD for the automatic compensation of sample temperature.


  • Easy Installation into 3/4″ FNPT Standard Pipe Tee
  • The Latest Short Pulse Type Detection Method Technology
  • Built-In Temperature Sensor with Automatic Compensation
  • Front-End Fully Digital Detection Technology
  • Accurate & Stable Measurement with Ultra-Low Drift
  • Built-In Transmitter without Pre-Amplifier or Meter Head
  • (2) 4-20mA Isolated Analog & RS-485 Modbus Digital Outputs
  • Stainless Steel Housing Suitable for Harsh Environments
  • Pollution-Resistant & Anti-Interference Design
  • Specially Designed Electrode Greatly Improves the Long-Term Stability of the Sensor
  • Minimal Maintenance Required
  • Ultra-Low Detection 0.02µS/cm (50MΩ Resistivity)


Typical applications

The ST-725 is an industrial-grade, inline ultra-low conductivity sensor designed for pure & ultra-pure water applications. It can be used for ultra-low conductivity measurement of pure water, ultra-pure water and deionized water including:
  • Boiler Feedwater and Condensate
  • RO and EDI/EDR Process Water
  • Ion Exchange
  • Distillation
  • Semi-Conductor Cleaning
  • Degas Conductivity and Other Process Applications



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

01438 759 595

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