抄録
The test dust used in the NFPA recommended standard for the contaminant sensitivity must be obtained by classifying ACFTD, which is stated as the standard material, into the defined particle size ranges.
This report describes the method and results of classification with test dusts ACFTD, JIS 3rd: Silica dust and JIS 8th: Kanto Loam dust into particle ranges of 0-5, 0-10, .....0-80 micrometer.
Particle diameter distribution of the test dusts classified in this study and classified dust sent from the Oklahoma State University (OSU) are analyzed and compared. With the dust from OSU, the particle frequency decreases near the upper boundaries of the higher particle size ranges (greater than 0-40μm range), hence the discrimination between the classified dusts of 0-50μm range and 0-80μm range is difficult.
It was recognized that the description of t he particle classification in the NFPA recommended standard should be revised to yield stricter definition.