is the International Standard Instrument used to measure the hardness
of rubber or rubber-like materials. Durometers measure hardness
by the penetration of an indentor into the rubber sample. The
calibrated reading is expressed
in a number value. The hardness values are always expressed in
terms of plus or minus (±) five points (example: 60±5
It is important to note that when testing hardness of a rubber sample,
the material should not be less than ¼" thick (.250").