More Information from an Optical Particle Counter
DANIEL MURPHY,
NOAA CSL Abstract Number: 107
Working Group: Instrumentation and Methods
AbstractOptical particle counters are a basic instrument for aerosol research. I will present a new design for an optical particle counter that combines aerodynamic and optical sizing, but with extremely simple optics: one prism, one lens, one mirror, and one detector. A polarizing prism is the most novel element. The result is an optical counter with much more precision than a scattering-only optical particle counter and better calibration stability. The design can retrieve not only a size distribution but also information about the density and sphericity of the particles. The design can be optimized for various particle size ranges such as 0.1 to 2 µm or 0.5 to 5 µm.
The new design also incorporates a simple mirror geometry that largely eliminates the classic problem of non-monotonic scattering of laser light for particles with radii similar to the laser wavelength.