This is a material characterization technique which is used to study the dimensional stability of a sample. The dimensional stability refers to the physical property of a material that represents its ability to maintain its original boundaries when subject to changes of temperature and humidity.
This standard covers the determination of the coefficient of linear thermal expansion for plastic materials that have a coefficient of expansion greater than 1 µm/m oC. This is determined by using a vitreous silica dilatometer. The thermal expansion of a plastic is composed of a reversible component on which are superimposed changes in length due to changes in length due to changes in moisture content, curing, loss of plasticizer or solvents, release of stresses, phase changes and other factors.