3.1 This test method is used to evaluate sulfur for suitability as a rubber vulcanizing agent. Sulfur particles must be small enough to dissolve in rubber during cure to produce a uniform network of cross-links. This test method is used as a quality control method to ensure that large particles are not present (and to determine if the sulfur follows a typical pattern for size distribution).

1.1 This test method covers the particle size measurement of the coarse fraction of ground sulfurs. It is limited to measurement of particles greater than 45 μm (No. 325 sieve). If the sulfur is very fine and the screens become plugged by the caking of the sulfur, it may be necessary to use a wet sieve procedure instead.

1.2 The values stated in SI units are to be regarded as the standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.