This International Standard specifies methods for
the determination of compression set characteristics
of vulcanized and thermoplastic rubbers at ambient,
elevated or low temperatures.
The methods are intended to measure the ability of
rubbers of hardness within the range 10 IRHD to
95 IRHD to retain their elastic properties at specified
temperatures after prolonged compression at constant
strain (where possible 25 %) under one of the
alternative sets of conditions described. For rubber
of hardness greater than 80 IRHD, a lower compression
strain is used: 15 % for a nominal hardness
from 80 IRHD to 89 IRHD and 10 % for a
nominal hardness from 90 IRHD to 95 IRHD.