Applications of mica track microfilters: surveillance of hot contaminated air at an industrial plant

Mica Track Microfilters (MTM) are produced by irradiation of mica with heavy ions at the UNILAC (GSI, Darmstadt) and subsequent etching. The properties of MTM will be shortly summarized. We describe the use of MTM at an industrial plant for test purposes under industrial conditions. MTM are placed into a cascade impactor into the exit gas stream of a sinter oven. Under our conditions 97% of the α-active aerosols are collected on the first MTM. The air throughput of our system is appr. 50 to 200 l/h at a pressure difference of 200 mbar. The aerosol-loaded MTM allow, among others, α-spectroscopy and particle-size determinations in an elegant manner. Finally, we describe shortly a radon-personal-dosimeter using MTM. (author)