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Distribution of mean particle concentration by measured particle size. Total of 133 sample measurements were taken with a mean of 1205 particles measuring 0.3 µm in diameter, 414 particles at 0.5 µm in diameter, 78 particles at 1.0 µm in diameter, 12 particles at 2.5 µm in diameter, 2 particles at 5.0 µm in diameter, and a mean of 1 particle at 10 µm in diameter.
