FSSP300

• Full Name: Forward Scattering Spectrometer Probe, Model 300, with Signal Processing Package for Optical Particle Counters SPP-300

• Short Name or Acronym: FSSP-300 or SPP-300

• Measurements Provided: size distribution and concentration of aerosol and cloud particles ~0.3 to 20 um diameter in 30 size bins, 10 sps

• Manufacturer or Builder of the Instrument: original probe version by PMS, Particle Measuring Systems; later electronics upgrade and data interface SPP-300 by DMT, Droplet Measurement Technologies

• Operational Status:

  • requestable, ready for deployment

• General Description:

  • 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.

• Measurement Characteristics:

  • Overall estimate of uncertainty: See references in the "Documentation" section at the bottom of this page.
  • Response time: The sample frequency can be up to 10 Hz
  • Precision: in diameter, the precision is about 0.05 micrometer in the smallest channels
  • Other measurement characteristics (comments on signal/noise, bias limits, etc):
    • Uncertainty is size is affected by variability in the possible indices of refraction of atmospheric particles and by the higher ambiguity introduced by variations in the Mie-scattering curves for the 1-8 micrometer size range.

• Lead Contact: Jorgen Jensen

Documentation

• Descriptive Publications

  • Baumgardner, D., J. E. Dye, and B. W. Gandrud, 1992: Interpretation of measurements made by the forward scattering spectrometer probe (FSSP-300) during the Airborne Arctic Stratospheric Expedition. J. Geoph. Res., 97, NO. D8, 8035--8046

  • Dye, J. E., et al., 1990: A survey of particle measurements in the Arctic from the Forward Scattering Spectrometer Probe Model 300. Geoph. Res. Letters, 17, 409--412 (March Supplement 1990)

  • Strapp, J. Walter, W. R. Leaitch, P. S. K. Liu, 1992: Hydrated and Dried Aerosol-Size-Distribution Measurements from the Particle Measuring Systems FSSP-300 Probe and the Deiced PCASP-100X Probe. J. Atmos. Oceanic Technol., 9, 548–555.

  • RAF Bulletin 24 description

• Documentation of the Processing Algorithm(s): See the Technical Note on Processing Algorithms at this URL (fix when available)