Process Instruments has developed the OxySense range, which includes sophisticated dissolved oxygen DO controllers designed to work seamlessly with their cutting-edge optical DO sensors. These DO controllers offer versatile options for monitoring, displaying, and controlling dissolved oxygen levels in various water treatment applications, providing water treatment professionals with powerful tools for managing dissolved oxygen levels effectively.

Controller Options

The OxySense range offers two primary controller options, each catering to different needs and complexities of dissolved oxygen control:

1. CRONOS® OxySense Controller:
   • High-quality, cost-effective solution
   • Multilingual interface
   • High-resolution grayscale display
   • 9-button navigation for ease of use
   • Graphing and datalogging capabilities
   • IP65/Nema 4x enclosure suitable for wall, panel, pipe, or pole mounting
   • Optional features include:
     • Modbus RS485/LAN communication
     • Profibus DPV 1 support
     • Capability to handle up to two sensors
     • PID/flow proportional controls
     • Remote sensor support
     • Colour display option
2. CRIUS® 4.0 OxySense Controller:
   • Incorporates all CRONOS® features
   • High-resolution colour display
   • Intuitive user interface
   • Downloadable data logs
   • Customisable home pages
   • Enhanced capabilities:
     • Support for up to four sensors
     • Remote access via LAN
     • Remote access via 3G/4G networks

Key Features of OxySense Controllers

Both the CRONOS® and CRIUS® 4.0 controllers offer several advantages for dissolved oxygen monitoring and control:

1. Compatibility with advanced optical DO sensors
2. Support for optional self-cleaning and self-verification features
3. Stability and reliability for excellent process control
4. Suitability for all dissolved oxygen applications
5. Extended maintenance intervals of up to 36 months
6. Calibration intervals of up to 36 months

These features make the OxySense controllers particularly well-suited for applications such as aeration lane blower control and oxidation ditch dissolved oxygen control.

Operational Principle

The OxySense controllers work in conjunction with optical luminescent DO sensors. These sensors operate on the following principle:

1. A sensing element (lumiphore) is illuminated with blue light.
2. The lumiphore emits red light in response, with intensity inversely proportional to oxygen concentration.
3. There’s also a time delay between blue light emission and red light response, which is inversely related to oxygen content.
4. The controller interprets these signals to provide dissolved oxygen readings in ppm or mg/l.

This advanced technology offers greater stability and abrasion resistance compared to traditional electrochemical devices.

Applications

The OxySense DO controllers are suitable for a wide range of dissolved oxygen monitoring and control applications, including:

• Wastewater treatment plants
• Drinking water treatment
• Environmental monitoring
• Aquaculture
• Industrial processes requiring precise DO control

Unique Control Features

The OxySense controllers offer several unique features that enhance their functionality:

1. AutoClean: An optional feature that allows the system to automatically clean the sensor at user-defined intervals, reducing maintenance requirements.
2. AutoVerification: Another optional feature that enables the controller to perform automatic in situ sensor verification, potentially eliminating the need for manual inspections for extended periods.
3. PID/Flow Proportional Controls: Available on both CRONOS® and CRIUS® 4.0 models, these advanced control options allow for precise regulation of dissolved oxygen levels in various processes.

Conclusion

The OxySense range of DO controllers represents a significant advancement in dissolved oxygen monitoring and control technology. By combining user-friendly interfaces, advanced control options, and compatibility with state-of-the-art optical sensors, these controllers offer water treatment professionals a reliable, low-maintenance solution for dissolved oxygen management. Whether used in wastewater treatment, aquaculture, or any other application requiring precise DO control, the OxySense controllers provide a powerful tool for managing dissolved oxygen levels efficiently and effectively.