Characterization of the Performance of a Novel Low-Cost, Low-Power Narrow-Band Oxygen Sensor for Small Engine Applications Using a Propane Burner Test Stand (2 of 3)

Global concerns over pollution have led to increasingly strict emissions legislation targeting small engines, which currently pollute at a much greater level than modern multi-cylinder automotive engines. Closed-loop control may be required to meet many future legislation requirements; however, such systems can be impractical due to high added component costs. A necessary component for closed-loop engine control is an oxygen sensor. Existing automotive oxygen sensors are too large, require too much power, and are far too expensive to be suitable for the vast majority of the global small engine applications; therefore, some manufacturers have developed smaller and/or unheated versions based on their existing sensors to meet this emerging need. The ability to miniaturize resistive based sensors well below that of traditional Nernst (zirconia based) oxygen sensors affords the opportunity to meet future emissions standards with less of an impact on cost.

The performance of a novel low-cost, low-power narrow-band oxygen sensor was compared with several automotive as well as newer oxygen sensors developed for the small engine market. Sensor performances are compared at various exhaust gas temperatures on a propane burner test stand under open-loop control to determine sensor response to exhaust gas changes, and under closed-loop control where the sensor controls the switching of the test stand between rich and lean states. Results indicate this sensor technology has improved performance and is well suited for many applications that would otherwise not have a cost-effective sensor for closed-loop control to meet emerging emissions standards.