Abstract
Satisfactory reproducibility, sensitivity and efficiency were found in samples for oil mist concentration taken by either the electrostatic precipitator or by glass fiber filters. Membrane filters and standard laboratory filter papers were unsuitable. Determination of size frequency distributions by stage weights from a commercial cascade impactor gave most promise as a routine field sampling method; membrane filter sheet was used on the impactor slides as a collecting reservoir. Microscopic methods for size frequency distribution were more tedious and the collection of suitable samples was more difficult. Light scattering photometers give the most convenient and accurate size frequency distribution where concentration is not too high.