Thermomechanical analysis or TMA is a simple yet very useful technique that can measure coefficient of thermal expansion, Tg and the dimensional change accompanying the relaxation of stress stored in a material. As shown in the illustration the dimensional change of a material with temperature (or time) is measured in a controlled atmosphere and under controlled load. Measurements may be made in compression (shown) or in tension, e.g. on a film or thin sample.
TMA is a technique used for testing materials. By measuring the size of the material. When it gets hot The atmosphere is determined as a function of temperature, the frequency samples are tested.