Robert Schrobenhauser

Detection of the mass of fine particulate matter using light scattering and inertial filtering in a miniaturized sensor setup

We present a miniaturized sensor setup capable of determining the mass of airborne particles employing inertial filtering and size information provided by an enhanced light scattering intensity ratio technique using Fresnel lenses. The method consists of two measurement steps and is based on the particle density-dependent filtering behavior of impactors. Measurement results using polystyrene latex and silica particles in a size range of 300?1600?nm show good agreement with theoretical expectations.

Highly sensitive laser-based sensor for nanoparticles in air using a dual-ring-mirror setup.

One of the most frequently applied techniques to detect nanoparticles in air is analyzing laser light scattering. This technique is very flexible while offering high accuracy and reliability. Yet its functionality highly depends on the sensitivity of the measurement system components. Especially for miniaturized sensor devices with limited space, additional techniques are needed to preserve high intensity of scattered light. In our work we demonstrate a technique using two spherical ring mirrors to identify nanoparticles with diameters below 100 nm in a forward-scattering setup. We succeeded measuring polystyrene particles with diameters of 92 nm with a signal-to-noise-ratio of more than 10.