Compression set of elastomer is a measurement of the ratio of elastic to viscous components of an elastomer's response to a given deformation. The test will be conducted as per ASTM D 395 and ISO 815 and the procedure lay out by the customers. Elastomer compression set measurement standards call for a 25% compression for a given time and temperature. The cross-section is measured after the load is removed. The difference between the final dimensions and the original dimensions is considered the compression set.