The TA Instruments Discovery DSC 25P is a high-precision pressure differential scanning calorimeter designed for analyzing thermal transitions, chemical reactions, and oxidative stability of materials under controlled pressure conditions. With a pressure range from 1 Pa to 7 MPa (0.0001 to 1,000 psi) and a temperature range from ambient up to 550C, it accommodates various inert, oxidizing, or reducing atmospheres. The optional Quench Cooling Accessory extends the operational temperature down to -130C. The instrument features a Fusion Cell with a pressure transducer, fixed pedestal-mounted sensor, rugged silver furnace, Tzero thermocouple, and temperature-controlled electronics, ensuring accurate temperature control and stable heat flow baseline performance. Its One Touch Away app-style touchscreen allows real-time monitoring of pressure, temperature, and time. The DSC 25P supports Modulated DSC (MDSC) under pressure conditions for separating complex thermal events and monitoring changes in specific heat capacity. It complies with various ASTM standards, including E537, E1782, D1858, D2009, D5885, and D6186, making it suitable for research and quality control in materials science, pharmaceuticals, and petrochemicals.