(1) PM10 and PM2.5 Samplers
Novel PM10 samplers make use of oil-coated impactor surface allowing high-particle loading capacity to minimize the frequent maintainance need. Novel non-bouncing PM2.5 samplers use small amount of oil to wash the impaction surface clean once every day to avoid particle bounce and the shift of the cutoff diameter while the maintainance frequency can be extended to several month long.
(2) Porous metal Denuder Sampler (PDS)
PDS can be used for sampling acidic and basic precursor gases and particulate matters at the same time. The PDS consists of a size-selective inlet to classify PM2.5, two acidic/basic coated porous metal discs to capture the basic/acidic precursor gases, a Teflon filter to collect particles, and back-up filters to collect the semi-volatile materials evaporated from collected particles. The backup Nylon filter is used to collect NO3- and Cl- ions while the backup acid nitric-coated Quartz filter is used to collect NH4+ ion. The PDS can thus be used for determining the accurate true mass concentrations of gases and particles simultaneously with evaporation loss correction.
