SUMMER COLD START AND NANOPARTICULATES OF SMALL SCOOTERS

Small scooters are very much used in the congested centers of the European cities. Even if there is a continuous technical progress, the small two-wheelers are a remarkable source of air pollution. During the research programs of the Swiss Federal Office of Environment Forests and Landscape (FOEFL) - and as a contribution to the European project ARTEMIS - analysis of limited and nonlimited emissions of scooters was performed. Exhaust emissions measurements of two Scooters, 4-stroke 125 cc and 2-stroke 50 cc, have been performed with and without catalyst. Identical driving cycles have been repeated and the influence of the cooling duration on limiting the emissions at cold start was investigated. A cold start in the temperature range of 20 - 25 degrees C can be regarded as a "summer cold start". As nonlimited emissions, the nanoparticulate emissions at cold and warm operating conditions were measured by means of SMPS, ELPI and NanoMet. The measurements were both at steady state and at transient operating conditions. The present work cleared up several details about the emissions of small scooters and confirmed the necessity of further activities to reduce these emissions. This would be an important contribution to improve the air quality in the cities. For the covering abstract see ITRD E122175.