GB/T 5950-2008 Method for measurement of whiteness of building materials and non-metal mineral products
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.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test method
5 Apparatus
6 Standard whiteboard
7 Specimen
8 Measurement
9 Calculation of measuring result
10 Test report
