They can cause lung cancer and other severe diseases: the minute soot particles from the exhaust gas of diesel-engined vehicles. The quantity of these particles has increased steadily. In order to nevertheless keep the harmful effects to one's physical health due to soot particles low, the limit values for diesel soot have been lowered drastically step by step, from 180 mg/km (EURO 1, 1993) down to 5 mg/km in EURO Standard 5, which is valid for new models, effective September of this year. In this standard, it is no longer only the mass concentration of soot particles which is considered, but their number, because this value is much more relevant for health hazards. To this end, novel measuring instruments must be approved. In order to adapt the entire measuring system from approval tests to calibrations and to the exhaust inspections at regular intervals to the new specifications, a pan-European project has been started. Under the auspices of the Physikalisch-Technische Bundesanstalt (PTB), several national metrology institutes are working together therein with cooperation partners from industry. The project is laid out for three years. Besides the diesel soot, it also addresses two additional materials problematic for health which pollute the air: smallest particles of platinum and other elements from catalyzers as well as those mercury compounds which are created in the combustion of fossil energy sources in power plants. The project began with a kickoff workshop on 6/7 June at PTB.
Whereas in 1980, only two percent of all new approved passenger cars were diesel-engined vehicles, today the proportion is already somewhat above 50 percent, in the case of some car models, even more than 90 percent. Actually, the proportion of coarse soot particles and thus the total mass in diesel exhaust gases were reduced
|Contact: Dr. Martin Thedens|
Physikalisch-Technische Bundesanstalt (PTB)