GB/T 3398.2-2008 in English

《GB/T 3398.2-2008塑料 硬度测定 第2部分：洛氏硬度》由TC15（全国塑料标准化技术委员会）归口，TC15SC4（全国塑料标准化技术委员会通用方法和产品分会）执行，主管部门为中国石油和化学工业联合会。
GB/T 3398《塑料　硬度测定》分为两个部分，本部分为GB/T 3398的第2部分，等同采用ISO 2039-2：1987《塑料―――硬度测定―――第2部分：洛氏硬度》（英文版）。
本部分于1988年首次发布。
本部分代替GB/T 9342-1988《塑料洛氏硬度试验方法》。
GB/T 3398的本部分规定了用洛氏硬度计M、L及R标尺测定塑料压痕硬度的方法。
本部分与GB/T 9342-1988相比主要变化如下：
―――范围中取消了“不适用于测定塑料薄膜、泡沫塑料”；
―――取消了定义；
―――增加了原理；
―――取消了对机架，钢球和计时装置的规定；
―――增加了3个引用标准，去掉了1个引用标准。

1 Scope

1.1 This part of GB/T 3398 specifies a method for determining the indentation hardness of plastics by means of the Rockwell hardness tester using the Rockwell M, L and R hardness scales.

1.2 A Rockwell hardness number is directly related to the indentation hardness of a plastic material; the higher the Rockwell hardness number, the harder the material. Due to a short overlap of Rockwell hardness scales by this procedure, two different Rockwell hardness numbers of different scales may be obtained on the same material, both of which may be technically correct.

1.3 For materials having high creep and recovery, the time-factors involved in application of the major and minor loads have a considerable effect on the results of the measurements.

1.4 An alternative method of using the apparatus to give hardness on the Rockwell-o hardness scale is specified in the annex which shows how this scale may be related to the hardness measurement of GB/T 3398.1.

2 Normative References

The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of GB/T 3398. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.

GB/T 2411-2008 Plastics and Ebonite — Determination of Indentation Hardness by Means of a Durometer (Shore Hardness) (ISO 868:2003, IDT)

GB/T 2918-1998 Plastics — Standard Atmospheres for Conditioning and Testing (idt ISO 291:1997)

GB/T 3398.1-2008 Plastics — Determination of Hardness — Part 1: Ball Indentation Method (ISO 2039-1:2001, IDT)

Foreword I
1 Scope
2 Normative References
3 Principle
4 Apparatus
5 Test Specimen
6 Conditioning
7 Procedure
8 Expression of Results
9 Test Report
Annex A (Normative) Determination of Rockwell-a Hardness
Bibliography