泡沫塑料 低温下的硬质材料线性热膨胀系数的测定

[中文适用范围]： 指定两种确定线性热膨胀系数的方法。 方法 A 是首选方法，它给出了选定温度下大样本的值。 应采用方法 B 来获得低温与环境温度之间的温度区间的平均系数。 附件中详细描述了两种方法的测试装置。 [外文原描述]： Specifies two methods for determing the coefficient of linear thermal expansion. Method A is the preferred method, it gives a value on a large sample at a chosen temperature. Method B should be employed to obtain an average coefficient for the temperature interval between the cryogenic temperature and the ambient temperature. In an annex the test apparatures for both methods are described in detail.