Measurement of changes in physical or chemical properties of materials as a function of temperature, usually heating or cooling at a uniform rate. (i) Differential thermal analysis (DTA), measures temperature difference (ΔT) between a sample and reference material. (ii) Differential scanning calorimetry (DSC), measures the differential heat flow between a sample and reference material. (iii) Thermogravimetric analysis (TGA), measures weight loss or gain.