This standard specifies a general test method for determining the thermal stability of substances using Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC) techniques. The core principle involves precisely measuring the thermal effects (i.e., enthalpy changes) of a sample during heating due to physical or chemical changes (such as melting, decomposition, or oxidation) through programmed temperature control, thereby obtaining key thermal stability parameters like the onset decomposition temperature and reaction enthalpy. The method has a broad scope of application, covering solids, liquids, and pastes, and can be conducted over a wide temperature range from -50°C to 1500°C, under either inert or reactive atmospheres. The standard explicitly states that the essential instruments for performing this test are a Differential Thermal Analyzer (DTA) and/or a Differential Scanning Calorimeter (DSC).