GB/T 5950-2008Method for measurement of whiteness of building materials and non-metal mineral products (English PDF)

1 Scope

This standard specifies the method for measurement of whiteness of building materials and non-metal mineral products.

This standard is applicable to measurement of whiteness of white and near white ceramics, coatings, white cement, talc, kaolin, wollastonite, gypsum, heavy and light calcium carbonate and other building materials and non-metal mineral products.

2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions, of any of these publications do not apply. However, parties to agreements based on this standard 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 document referred to applies.

GB/T 3977 Specification of colors

GB/T 3978 Standard illuminants and illuminating-viewing conditions

GB/T 3979 Methods for the measurement of object color

GB/T 5698 Glossary of color terms

GB/T 7921 Uniform color space and color difference formula

GB/T 8170 Rules for rounding off of numerical values

GB/T 9086 The white standard plate for colorimetry and photometry

GB/T 11942 Colorimetric methods for colour building materials

GB/T 17749 Methods of whiteness specification

GSB A 67001 Physical standard for whiteness of magnesium oxide

GSB A 67002 White ceramic standard plate

GSB A 67006 Physical standard for whiteness of barium sulfate

GSB Q 30001 Series standard whiteboard of matt glazed ceramics

JJG 512-2002 Verification regulation of the whiteness meter

3 Terms and definitions

For the purposes of this standard, the terms and definitions given in GB/T 5698 apply.

4 Test method

When the whiteness of an ideal complete reflective diffuser with a spectral reflectance ratio of 1 is 100, and the whiteness of an absolute blackbody with a spectral reflectance ratio of 0 is 0, the tristimulus value of the specimen is measured according to the conditions stipulated in this standard, then the whiteness is calculated using the equations stipulated, and the hue angle, color degree and color difference between specimens may be calculated.