ISO 868:2003规定了通过两种类型的硬度计测定塑料和硬橡胶的压痕硬度的方法:A型用于较软的材料，D型用于较硬的材料。该方法允许测量初始压痕或指定时间段后的压痕或两者。 该方法是一种经验方法，主要用于控制目的。通过该方法测定的压痕硬度与被测材料的任何基本性能之间不存在简单的关系。出于质量标准的目的，建议对较软的材料使用ISO 48，橡胶，硫化橡胶或热塑性塑料-硬度的测定（硬度在10 IRHD和100 IRHD之间）。

ISO 868:2003 specifies a method for the determination of the indentation hardness of plastics and ebonite by means of durometers of two types: type A is used for softer materials and type D for harder materials. The method permits measurement either of the initial indentation or of the indentation after a specified period of time, or both. This method is an empirical method intended primarily for control purposes. No simple relationship exists between indentation hardness determined by this method and any fundamental property of the material tested. For specification purposes, it is recommended that ISO 48, Rubber, vulcanized or thermoplastic -- Determination of hardness (hardness between 10 IRHD and 100 IRHD), be used for the softer materials.