| abstract |
An improved nanoparticle counter having a gas treatment stage prior to a nanoparticle counter, the gas treatment stage comprising an oxidation catalyst and an absorber effective in absorbing gaseous sulfur compounds and, desirably, nitrogen oxides which, when cooled, nucleate and form particles, the gas treatment step one or more flow monoliths are applied, the gas treatment step being applied to a metal foil monolith of not more than 400 cells / inch 2 and a film thickness of not more than 50 microns and having an open area of at least 90%. |