This procedure is used to determination of whether a combustible dust meets the criteria of a Class II dust as defined by OSHA Explosion Severity criteria. Sample size: 200 g.
ASTM E 1226 Standard Test Method for Pressure and Rate of Pressure Rise for Combustible Dusts is used to determine maximum deflagration pressure, rate of pressure rise, and KST. This information is required to design explosion protection systems such as pressure relief vents (per NFPA 68) and suppression systems. Sample size: 1000 g
ASTM E 1515 Standard Test Method for Explosible Concentration of Combustible Dusts is used. Dust samples are ignited at progressively reduced dust cloud concentrations until the concentration is reached at which flame propagation will no longer occur. Sample size: 500 g
Conducted in a manner similar to ASTM E2931. Dust cloud deflagration tests are carried out in a 20 liter spherical vessel in which the partial pressure of oxygen is progressively reduced (by partial evacuation and back filling with nitrogen) until combustion can not be initiated. Sample size: 500 g
ASTM E 2019 Standard Test Method for Minimum Ignition Energy of a Dust Cloud in Air . Also IEC 1241-2-3. Small quantities of dust are pneumatically thrown into suspension and ignited with an electric spark. The energy content of the spark is progressively reduced until the dust will no longer ignite. Minimum ignition energy is reported in mJ. Sample size: 200 g
ASTM E 1491 Standard Test Method for Minimum Ignition Temperature of Dust Clouds. Also to IEC 1241-2-1 method B. The minimum temperature at which a dust cloud will ignite is measured by pneumatically conveying a dust sample through a vertically-oriented cylindrical electric furnace. The minimum ignition temperature is the lowest furnace temperature that results in propagation of flames from the bottom of the furnace. Sample size: 100 g