Oil-soaked sintered impactors for the ELPI in diesel particulate measurements

Diesel soot overloads the ELPI-impactor rapidly if it is equipped with the standard flat-surface impactors. This non-ideal behaviour was studied recently (J. Aerosol Sci. 32 (2001) 1117). It was found that rapid overloading, or surface build-up, is a result of a fluffy bed of soot particles that covers the impactor surfaces and starts to filter airborne soot particles. This paper reports additional results with oil-soaked sintered impactors for the ELPI. It is demonstrated that (rapid) overloading is eliminated with oil-soaked sintered impactors. The maximum allowed mass load for the ELPI impactor is increased 50-fold.