Forward Scattering Spectrometer Probe, Model 300

The FSSP-300 is a wing-mounted probe in a standard PMS canister. Particle detection and sizing is based on laser light scattering and occurs in free stream. There is no air sample inlet. The instrument resembles a standard FSSP-100, but with some significant differences. The FSSP-300 has been optimized for the detection of aerosol particles having diameters from 0.3 to 20 micrometers, and the relationship between amplitude of the collected light and particle size assumes an index-of-refraction of 1.58 instead of that for water. Also, the depth-of-field determination is made in a different way, in which a slit is used over an "acceptance" detector instead of a spot over a "rejection" detection as in the FSSP-100. This "acceptance" technique is the same as that used for the Cloud Droplet Probe.