EFFECT OF TEMPERATURE GRADIENTS ON CALORIMETRIC MEASUREMENTS IN FLUIDS

由于扫描过程的动态性质，温度 在扫描过程中，整个流体样本都存在梯度 量热计测量。因此，当扫描量热计 用来进行热容测量的滞后效应 当一个相移时，样品中的温度梯度会使输出失真。 就会发生转变。多年来，已经有几个计划 开发来纠正这种扭曲；然而，到目前为止，还没有人 试图量化样本中的温度梯度，并 确定其与测量输出的实际关系。我们有 开发了几个量热计的详细的二维RC模型 设计，并对动态温度梯度进行了评估 测量过程中的流体样本，使用商业广告 电路模拟(SPICE)程序。这些分析都揭示了 由温度梯度引起的几个误差的来源 测量，并允许我们重新设计和重新评估新的 量热仪在建造前按顺序在软件中进行设计 以减少这些错误的大小。

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.