ASTM D518-99

1.1 This test method covers three test specimen procedures that estimate the comparative ability of rubber compounds to withstand the effects of normal weathering, or exposure in an atmosphere containing controlled amounts of ozone. It does not apply to testing of electrical insulation or other rubber parts where high concentrations of ozone prevail due to electrical discharge, nor to testing of material ordinarily classified as hard rubber.

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.

1.1 This test method covers three test specimen procedures that estimate the comparative ability of rubber compounds to withstand the effects of normal weathering, or exposure in an atmosphere containing controlled amounts of ozone.

It does not apply to testing of electrical insulation or other rubber parts where high concentrations of ozone prevail due to electrical discharge, nor to testing of material ordinarily classified as hard rubber.

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.

In the development of rubber compounds for use in applications where ozone cracking is objectionable, it is necessary to have a test in which simple comparative performance for resistance to cracking can be evaluated. This test method can be used for this performance comparison.

This test method is not suited for use in purchase specifications, not only because correlation with service life is uncertain, but because the results from duplicate specimens tested in different locations do not ordinarily give the same values. No exact relation between the results of the test and actual service performance is given or implied. The test is principally of value when used for comparisons between two or more rubber compounds.

METHOD A—EXPOSURE OF STRAIGHT SPECIMENS