Tension set is
defined as the proportion of applied strain remaining after a test
piece has been stretched and allowed to retract in a specified
manner.It is determined by stretching a test piece of standard
dimensions to a suitable length in the apparatus for a specified
time and temperature and then allowed to recover. The tension set is
calculated as percentage of initial strain. The machine is as per
I.S.3400 (PART 13)1972.