Optimising Boiler Efficiency with Zirconia Oxygen Sensors from SST

June 19, 2025

Boiler tanks

Maximise Boiler Efficiency with Zirconia Oxygen Sensors from SST

Optimising boiler combustion efficiency is critical for reducing emissions, saving fuel, and lowering operational costs. This article explores how flue gas oxygen sensors—specifically zirconium dioxide (zirconia) sensors from SST—can help enhance performance in biomass, coal, natural gas, and oil-fired boiler systems.

Why Monitor Flue Gas?

Efficient combustion relies on achieving the ideal air-to-fuel ratio. If the ratio is incorrect—either too much fuel or too little oxygen—it results in incomplete combustion, leading to:

  • Unburnt fuel waste
  • Higher emissions of toxic gases (CO, NOx)     
  • Increased maintenance costs
  • Reduced system lifespan

By continuously monitoring oxygen levels in the flue gas (exhaust stream), it’s possible to fine-tune combustion in real time, improving energy output and minimising waste.

Enhancing Combustion with Oxygen Gas Sensors

Fuel represents a significant portion of operational overhead in industrial and commercial boiler systems. Real-time measurement of flue gas oxygen levels is essential to maintain peak efficiency and maximise return on investment.

Using a zirconia oxygen sensor in a closed-loop feedback system, the boiler controller can automatically adjust the air-to-fuel ratio—helping to stabilise combustion, especially when fuel composition varies.

OXY-Flex Oxygen Analyser: In-Situ Efficiency Monitoring

 

The SST OXY-Flex Oxygen Analyser is a robust, high-performance sensor designed specifically for combustion control. It measures oxygen levels directly in the flue gas and relays data to the boiler control system, enabling dynamic optimisation of combustion conditions.

Key features:

  • Zirconium dioxide sensor: Withstands harsh flue gas environments at temperatures up to 400°C (752°F)
  • Versatile outputs: Choose from 4–20 mA, 0–10 VDC, or RS232 for seamless integration
  • Configurable ranges: Multiple measurement ranges available for tailored performance
  • Extended lifespan: Non-depleting sensing technology offers up to 10 years of service life
  • Robust construction: Housed in stainless steel for durability in industrial settings

 

 

 

Advantages of SST’s Zirconia Oxygen Sensors

SST offers a wide range of zirconia oxygen sensors specifically designed to support combustion monitoring in harsh environments. These sensors help reduce carbon emissions, optimise fuel usage, and extend system life.

Benefits at a glance:

  • Wide measurement range: Detects oxygen from 0.1% to 25%
  • Non-depleting cell: Long service life, low total cost of ownership
  • Fast response time: As low as 4 seconds
  • Tool-free calibration: Calibrate using ambient air (20.7%) or a known gas mix
  • Low maintenance: Simple installation and minimal servicing
  • Compact, integrated design: Sensor and electronics in a single housing
  • Multiple outputs: Compatible with common industrial control systems (4–20 mA, 0–10 V, RS232/485)
  • RoHS compliant & ISO9001:2015 certified

Ready to Improve Your Boiler Efficiency?

Whether you’re working with biomass, fossil fuels, or mixed combustion sources, SST’s zirconia oxygen sensors offer a reliable, cost-effective solution for flue gas analysis and combustion optimisation.

If you’d like more information or support in selecting the right sensor for your application, please contact our technical team—we’re here to help.