An apparatus for real-time measurement of mass, size and number of solid particles of particulate matter in engine exhaust has a catalytic stripper to remove at least about 90% of a volatile fraction of the particulate matter and pass at least about 95% of a solid fraction of the particulate matter, and a micro-dilution tunnel to cool the test medium after passing through the catalytic stripper and prior to passing through a particle sizer and counter system. A method embodying the present invention includes removing a volatile fraction of the particulate matter carried in a sample test stream and comparing the sample after removal of the volatile fraction with a second sample in which the volatile fraction has not been removed. The difference between the two samples represents liquid phase of the volatile fraction of the tested exhaust gas.
Imad Said Abdul-Khalek