EFFECT OF TEMPERATURE GRADIENTS ON CALORIMETRIC MEASUREMENTS IN FLUIDS

由于扫描过程的动态性质， 在扫描过程中，梯度存在于整个流体样品中 热量计测量。 因此，当扫描量热仪 用于进行热容测量，滞后的影响 样品中的温度梯度使输出失真， 过渡发生。 多年来，已经有几个方案 开发来纠正这种扭曲;然而，迄今为止，没有人 试图量化样品中的温度梯度， 确定其与测量输出的实际关系。 我们有 开发了详细的，二维钢筋混凝土模型的几个热量计 设计，并评估了动态温度梯度， 在测量过程中，使用商业 电路模拟（SPICE）程序。 这些分析都表明， 几个温度梯度引起的误差的来源， 测量，并允许我们重新设计和重新评估新的 热量计设计软件之前，他们被构造，为了 以减小这些误差的幅度。

Due to the dynamic nature of the scanning process, a temperature gradient exists throughout the fluid samples during scanning calorimeter measurements. As a result, when a scanning calorimeter is used to make heat-capacity measurements, the effect of the lagging temperature gradient in the sample distorts the output when a phase transition occurs. Over the years, several schemes have been developed to correct this distortion; to date, however, no one has attempted to quantitate the temperature gradient in the sample and determine its actual relationship to the measured output. We have developed detailed, two-dimensional RC models of several calorimeter designs, and have evaluated the dynamic temperature gradients in the fluid samples during the measurement process, using a commercial circuit-simulation (SPICE) program. These analyses have both revealed the source of several temperature gradient-induced errors in the measurements, and allowed us to redesign and re-evaluate new calorimeter designs in software before they are constructed, in order to reduce the magnitude of these errors.