Hardness measurement is a way to practically determine the degree of vulcanization of a rubber sample. One of the most important and commonly used measurements for non-destructive hardness testing is the IRHD (International Rubber Hardness Degree).

International testing standards specify a primary load of 5 seconds and then a secondary load of 30 seconds. H W Wallace has developed a predictive technique which allows these times to be reduced significantly.

Using a Wallace Cogenix Micro Hardne
Source: NDT