Abstract: The SPIRAL SAMPLER is a sampler for airborne particles. The spiral groove in the sampler allows for sticky or liquid particles as well as solid or bouncy particles of any given aerodynamic diameter to be sampled with the same efficiency. The SPIRAL SAMPLER does not require any oil or grease, which may become dislodged during operation and contaminate the particle deposit. By varying the dimensions of the inlet tube and the spiral groove, as well as the number of turns of the spiral, samplers may be made for sampling at any desired flow rate and with chosen particle size cutoffs. The SPIRAL SAMPLER may be scaled to any size, from personal to an area sampler. For sampling in areas with high loadings of large particles, a particle trap may be used to effectively and compactly separate oversized particles which would adversely affect the sampler operator.

Abstract: A universal impactor for sampling airborne particles has a slit nozzle that tapers in width along its length. The slit nozzle is in a plate that is thicker near wide parts of the slit and is thinner near narrow parts of the slit. An impaction plate beneath the slit is wider below wide parts of the slit and narrower below narrow parts of the slit. The impaction plate is sloped so that the impaction surface is at a greater distance below wide parts of the slit, and at a lesser distance below narrow parts of the slit. A passage adjacent to the impaction plate allows penetration of unimpacted particles to a particle collector or sensor. An air mover provides flow through the apparatus. The impactor has a particle impaction efficiency that varies smoothly with particle size and a curve of particle penetration efficiency vs. particle size that closely meets any predetermined sampling criteria.