Gelatin as a target medium for ballistic sizing of aerosol particles

Ballistic sizing of aerosol particles offers a novel solution to the unique constraints imposed by the possibility of in-situ particle measurement in remote (and extra planetary) environments. Initial theoretical considerations predicted that an appropriate material would allow for impacting aerosol particles to a measurable and predictable depth in the ballistic target. Low-concentration gelatin was investigated as a possible target medium that may allow for ballistic behavior for the low kinetic energies associated with aerosols. Highly monodisperse polymer resin particles were entrained in an air stream of measured velocity, and fired into 21% gelatin targets in ambient conditions. It was discovered that the ballistic behavior was negligible, possibly due in part to the effects caused by high target surface deflection under the application of the particle laden air jet. Therefore, low concentration gelatin would appear to be unsuitable for ballistic particle sizing, though there may be other suitable target media.