Oxidation Catalyst NOx Differential Monitoring

The patent implements a feedback mechanism by continuously monitoring NOx concentrations upstream and downstream of the oxidation catalyst and comparing the differential to threshold values. This feedback loop enables real-time assessment of catalyst performance and triggers diagnostic routines when degradation is detected, allowing maintenance or replacement decisions based on actual performance rather than fixed schedules.

The system performs self-diagnosis by using the existing NOx sensors and control module to automatically assess catalyst health. The control module executes diagnostic routines that interpret sensor data and determine catalyst performance status without requiring external inspection equipment or complex additional diagnostic systems.

The patent applies partial correction by adjusting sensor readings only when specific conditions indicate cross-sensitivity interference. Rather than implementing continuous complex calibration, the system uses conditional logic to apply corrections only when necessary, based on detected patterns such as ammonia presence or specific operating conditions that trigger cross-sensitivity issues.

The system changes measurement parameters dynamically by switching between different measurement modes or correction algorithms based on operating conditions. When cross-sensitivity is detected, the system adjusts how sensor readings are interpreted or corrected, rather than relying on fixed calibration parameters throughout all operating ranges.

The patent uses the NOx sensor differential as an intermediary indicator of catalyst performance. Rather than directly measuring complex catalyst properties such as surface area, pore structure, or active site concentration, the system measures the easily obtainable NOx concentration differential upstream and downstream of the catalyst, which serves as a proxy indicator of catalyst health and performance.

The system replaces complex physical or chemical diagnostic methods with electronic sensor-based measurement. Instead of using sophisticated techniques such as temperature-programmed desorption, chemisorption measurements, or microscopy to assess catalyst condition, the patent substitutes these with simple electronic NOx concentration measurements and differential calculations performed by the control module.