Federal Institute for Occupational Safety and Health (BAuA)

To measure exposure to nanoparticles and -fibres at workplaces, the aerosols are deposited on a silicon substrate with the thermal precipitator and imaged afterwards by scanning electron microscopy (SEM).The particle number is then determined by counting, based on 12x10 µm image sections from the TP-samples. To trace back the particle number collected with the TP to the particle number concentration of the sampled air in a comprehensible way, an adequate number of image sections must be evaluated. The number of SEM-images and the (maybe smaller) number of image evaluations must be balanced towards economic expense and necessary precision. The optimal number of SEM-images and image evaluations via probabilistic methods will be calculated within this project.

Unit 3.6 "Statistical Methods in Epidemiology and Biometrics"
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