Abstract
Discussions about particulate matter emission caused by road traffic, especially by diesel vehicles, are noticeably focusing on particle size and number distribution. Referring to recent health studies small particles, even regardless of their chemical composition, are under suspicion of causing health risks. Therefore it becomes an important question, if the reduction of the particulate mass emission is sufficient or the avoidance of small particles should be an additional development goal. This paper deals with measuring techniques and influences of engine type, operation conditions and fuel quality on particulate matter emission.