Standard No.:	GB/T 7962.18-2010
Chinese Name:	无色光学玻璃测试方法　第18部分：克氏硬度
English Name:	Test methods of colourless optical glass—Part 18:Knoop hardness
Professional Classification:	N05 Material and component for instrument and meter
ICS Classification:	81.040.01 Glass in general
Issued by:
Issued on:	2011-01-14
Implemented on:	2011-05-01
Status:	VALID
Replace:	GB/T7962.21-1987 Colourless optical glass test methods; Knoop hardness
Language:	English
File Format:	PDF
Word Count:	4000 words
Price(USD):	120 (USD)
Delivery:	via email in 1-3 business day

1 Scope

This part of GB/T 7962 specifies the test apparatus, test steps and data processing for the Knoop hardness of colourless optical glass.

This part is applicable to the measurement for Knoop hardness of colourless optical glass.

2 Normative references

The following documents contain provisions which, through reference in this part of GB/T 7962, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction 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 editions apply to this part.

ISO 9385 Glass and glass-ceramics - Knoop hardness test

3 Terms and definitions

For the purposes of this part, the following terms and definitions apply.

3.1
hardness
capability of the material partially preventing hard object from pressing into its surface

3.2
Knoop hardness
HK
abbreviation of Knoop microindentation hardness, which is tested using a quadrangular pyramid diamond indenter with symmetrical corner angles of 172°30′ and 130°