差示扫描量热法Differential scanning calorimetry

样品和参比（通常为空坩埚）同时按相同程序升温。样品发生吸热过程（熔融、蒸发、玻璃化转变）或放热过程（结晶、固化、氧化、分解）时，需要额外的热流来保持两者温度一致，这一差值被记录为 DSC 曲线。熔融峰的起始温度为熔点，峰面积正比于熔化焓；玻璃化转变表现为基线台阶（比热容变化）。热流型 DSC 测量温差换算热流，功率补偿型 DSC 直接测量补偿功率。

Sample and reference, usually an empty pan, are heated on the same programme. When the sample absorbs heat (melting, evaporation, glass transition) or releases it (crystallisation, curing, oxidation, decomposition), extra heat flow is needed to keep the two at the same temperature, and the difference is recorded as the DSC curve. The onset of a melting peak is the melting point and its area is proportional to the enthalpy of fusion; a glass transition appears as a step in the baseline from the change in heat capacity. Heat-flux DSC converts a temperature difference to heat flow, while power-compensated DSC measures the compensating power directly.

1887 年勒夏特列用热电偶测量黏土加热时的温度变化，1899 年罗伯茨-奥斯汀提出差热分析（DTA）。1962 年珀金-埃尔默公司的沃森和奥尼尔发明功率补偿型 DSC，可以定量测量热量，之后迅速成为高分子和药物研究的标准仪器。

In 1887 Le Chatelier measured the temperature of heated clays with a thermocouple, and in 1899 Roberts-Austen introduced differential thermal analysis (DTA). In 1962 Watson and O'Neill at Perkin-Elmer invented power-compensated DSC, which measures heat quantitatively, and it soon became standard in polymer and pharmaceutical research.

DSC 用于测定高分子的 Tg、Tm 和结晶度（实测熔化焓/100% 结晶熔化焓）、热固性树脂的固化度、药物纯度（范特霍夫方程分析熔点下降）和多晶型、蛋白质热变性温度、液晶相变、食品中淀粉糊化与油脂结晶、相变储能材料，以及含能材料的热安全性评价。

DSC measures polymer Tg, Tm and crystallinity (measured enthalpy of fusion divided by that of a 100% crystalline polymer), degree of cure of thermosets, drug purity (by van 't Hoff analysis of melting-point depression) and polymorphism, protein unfolding temperatures, liquid-crystal transitions, starch gelatinisation and fat crystallisation in food, phase-change energy-storage materials and the thermal safety of energetic materials.