Periodic Inspection of Exhaust Emissions from Low Pollutive Otto Engine Vehicles and Diesel Engine Vehicles

The practical qualification of two short test procedures developed for periodic measurements of in use Otto and Diesel vehicles with high emission levels has been proven. From the test results of these vehicles showing outlying emission levels it becomes evident that excessive pollutant concentrations or smoke emissions originate from defective engine components, or incorrect adjustments, respectively, which are relevant to the emission behaviour. Automation of the test procedures contributed to achieve a good reproducibility of the test readings and to keep the measuring time within reasonable limits.