Metal oxide-based resistive type sensor for the detection of carbon monoxide at room temperature

Our innovative CO sensor utilizes hydrated ruthenium oxide to detect carbon monoxide within a gas mixture with high sensitivity and selectivity at temperatures ranging from 25°C to 300°C.

The Need

Reliable and low-cost CO sensors with high sensitivity and selectivity are essential for environmental safety and industrial control, particularly to monitor combustion environments, automotive emissions, and various industrial processes, ensuring compliance with regulations and minimizing health hazards.

The Technology

The CO sensor is based on ruthenium oxide, which is partially hydrated to enhance its sensing capabilities. The sensor includes a pair of conductive electrodes connected to the ruthenium oxide surface. During operation, the gas mixture contacts the ruthenium oxide, and an electrical device applies a constant potential or current between the electrodes, measuring the resulting current or potential to derive the resistance. This setup allows accurate CO detection even in the presence of other interfering gases, operating effectively within a temperature range of 25°C to 300°C and detecting CO concentrations from 1 ppm to 1,000 ppm.

Commercial Applications

  • Automotive Industry: Monitoring and controlling CO emissions from vehicle exhaust systems.

  • Industrial Safety: Detecting CO in manufacturing and processing environments to ensure worker safety.

  • Environmental Monitoring: Measuring CO levels in urban and industrial areas for air quality assessments.

  • Smart Home Devices: Integrating into home safety systems for continuous indoor air quality monitoring.

  • Portable Detection: Developing handheld CO detectors for emergency responders and safety inspectors.


  • High Sensitivity: Detects CO concentrations as low as 1 ppm.

  • Selective Detection: Accurately measures CO even in the presence of other gases.

  • Ambient Temperature Operation: Functions effectively from 25°C to 300°C without requiring additional heating.

  • Low-Cost Manufacturing: Utilizes inexpensive materials and simple fabrication processes.

  • Compact Design: Easily integrates into various devices and systems for versatile applications.

Patent Protection

  • United States Patent No. 8,114,675

Loading icon