ASTM Standard E1877 provides Relative Thermal Index (RTI) and lifetime estimations from kinetic parameters determined by TGA. Traditionally, the Flynn and Wall method (ASTM E164) is used to generate the necessary kinetic parameter of activation energy and Arrhenius frequency factor. The Flynn and Wall approach is based on a series of experiments using linear heating rates between 1 deg C/min and 10 deg C/min. A minimum of four such experiments is required and upwards of two days of experimental time may be needed to obtain the desired information. Modulated TGA (MTGA~(TM)) provides an alternative approach to obtaining kinetic parameters. In MTGA, an oscillatory temperature program is superimposed over an underlying linear heating rate yielding kinetic information in a single, short experiment. For first order reactions, the two approaches provide equivalent kinetic parameters, but MTGA yields lifetimes estimations in about one quarter the time.
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机译：ASTM标准E1877根据TGA确定的动力学参数提供了相对热指数（RTI）和寿命估算。传统上，使用Flynn和Wall方法（ASTM E164）来生成必要的活化能动力学参数和Arrhenius频率因子。 Flynn and Wall方法基于一系列实验，使用的线性加热速率在1℃/ min和10℃/ min之间。至少需要进行四个此类实验，并且可能需要长达两天的实验时间才能获得所需的信息。调制的TGA（MTGATM）提供了获取动力学参数的替代方法。在MTGA中，在一个简短的实验中，将振荡温度程序叠加在基本的线性加热速率上，从而产生动力学信息。对于一阶反应，这两种方法提供了相同的动力学参数，但MTGA的寿命估计约为四分之一。
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