scope:

This International Standard specifies a test procedure for determining the compression set characteristics of vulcanized rubbers. The test is intended to measure the ability of rubbers of hardness within the range 30 to 94 International Rubber Hardness Degree (IRHD) to retain their elastic properties after prolonged compression at constant strain under one of the alternative sets of conditions described. With some rubbers, especially those above 85 IRHD, it may not be possible to achieve 25% compression strain. For such rubbers this method does not apply.