This test measures the longitudinal shrinkage of insulation insulation when exposed to elevated temperature as specified in AS23053 Rev A. Specimens are marked at a specified gauge length, exposed to the required temperature for the specified duration, then re-measured to determine the amount of shrinkage.
Excessive shrinkage can expose conductors at termination points and compromise the insulation system. This test verifies that the insulation material has adequate dimensional stability at the rated operating temperature.