Gas-borne particle measuring system - esp. for vehicle exhaust gas emission tests

摘要

An exhaust gas particle measuring system, esp. for vehicle exhaust gas tests, mixes the exhaust gases with air in a dilution tunnel from which a representative sample stream is withdrawn through a sampling tube by a gas pump and then supplied to a particle filter. The sampling tube has a mass flow meter (1) which affects the gas pump (2), the pump and the flowmeter pref. being connected together via a computing unit (3) which provides a constant gas throughput even when the flow resistance of the particle filter (4) increases. ADVANTAGE - The system is simpler and is much more accurate than conventional systems.