Standard No.:	GB 11186.3-1989
Chinese Name:	漆膜颜色的测量方法 第三部分:色差计算
English Name:	Methods for measuring the colour of paint films; Part 3:Calculation of colour differences
Professional Classification:	G50 Basic standard and general method for coating
Professional Classification:	GB National Standard
Issued by:
Issued on:	1989-03-01
Implemented on:	1990-01-01
Status:	VALID
Language:	English
File Format:	PDF
Word Count:	2000 words
Price(USD):	60 (USD)
Delivery:	via email in 1-3 business day

1 Scope and field of application

This standard specifies the method for the quantitative colorimetric evaluation of small colour differences between paint films.

Note: There are numerous formulae for calculating a colour difference from the colour co-ordinates of two specimens. For various reasons the results given by such formulae, including the one defined here, do not in all cases agree satisfactorily with visual perception nor are they likely to agree with each other. The CIE recommended in 1976 two formulae for general use. One of these, the CIE 1976 (L*a*b*) colour difference formula has proved to be of practical value for the colorimetric evaluation of paint films.

2 Normative references

GB 9761 Paints and varnishes - Visual comparison of the colour of paints
GB 11186.1 Methods for measuring the colour of paint films - Part 1: Principles
GB 11186.2 Methods for measuring the colour of paint films - Part 2: Colour measurement

3 Calculation