Sieve
Sampler - This is a mechanically simpler form of impinger. The instrument is more or less similar to that of slit sampler with an enclosed chamber. The particles containing microorganisms are distributed over the plate as separate air jets through several holes. Upon incubation these particles form colonies which can be counted.
For more efficient sampling and size grading of particles Anderson developed a multistage sieve device in which several impingers with holes of different sizes are arranged in series.
