This standard specifies the method for expressing the whiteness of object colors. It is expressed by whiteness W and W10, and light hue index TW and TW,10 under the lighting conditions of the standard illuminant D65. This standard applies to all "white" object colors (including non-fluorescent colors and fluorescent colors). GB/T 17749-1999 Method for expressing whiteness GB/T17749-1999 Standard download decompression password: www.bzxz.net
This standard specifies the method for expressing the whiteness of object colors. It is expressed by whiteness W and W10, and light hue index TW and TW,10 under the lighting conditions of the standard illuminant D65. This standard applies to all "white" object colors (including non-fluorescent colors and fluorescent colors).

G/T17749-1999
This standard is formulated according to the recommendation of Article 5.3 of the second edition of the International Commission for the Study of Colorimetry publication CIF No.15.2 (1986), and is completely consistent in technical content, and has taken into account the Japanese Industrial Standard JIS28715:1991. White is a special color among colors. It is a psychological, physiological and physical color. Whiteness is one of the direct or indirect flux indicators of many products. The whiteness is measured using the principle of colorimetry. It is easy to calculate and is related to the objective evaluation of whiteness. The CIE-derived degree formula of this standard has the following restrictions: the sample has no big difference in chromatic aberration and fluorescence, but must be a sample called "white", and the degree comparison is made between samples measured on the same instrument1 within a short period of time. (EH) The degree formula provides a relative evaluation of whiteness rather than an absolute evaluation. Also, since there are many whiteness formulas in history, and there are more than ten commonly used ones, this standard lists other rough whiteness formulas currently used in Appendix A (suggestive Appendix). It is an inevitable trend to use the degree formula specified in this standard, but this will There is a long process of gradual promotion and implementation.
Appendix A of this standard is a reminder appendix.
This standard is proposed by the State Building Materials Industry Bureau: This standard covers the National Whiteness Standardization Technical Working Group. This standard is drafted by the National Building Materials Bureau Standardization Institute of the China Institute of Metrology: The main drafters of this standard are: Shun Xiujin, Hu Weizuo, Zeng Xiaodong, Gong Jixian, Yin Jingning. wm1 Scope
National Standard of the People's Republic of China
Methods of expressing whiteness
Methods of whiteness specification GB/T 17749—1999
This standard specifies the method of expressing the color of objects. It is expressed by the color H and W:, and the hue index Tw and Tw.t under the standard lighting system Tu and lighting conditions.
This standard applies to all "white" object colors (including non-fluorescent colors and fluorescent colors). 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through their use in this standard. When this standard is published, the versions shown are valid. All standards will be revised. The parties using this standard should discuss the possibility of using the latest versions of the following standards. G13/T397S—1997 Method for measuring object color GB/5698—1985 Color terminology
GB/T 9840—1938
Relative measurement method of fluorescent sample color
3 Definitions
This standard adopts the following definitions.
3.1 Whiteness whitencss
Characterizes the degree of whiteness of an object, and is represented by the symbols W and W1:. The larger the whiteness value, the greater the degree of color in the object: the whiteness of a completely reflecting diffuser is equal to 100, 3.2 Tint index tint
Characterizes the degree of light hue in white, and is represented by the symbols T and w.1. When the light hue index is positive, the larger the value, the greater the degree of green; when the light hue index is negative, the larger the absolute value of the negative, the greater the degree of red. The light hue index of a completely reflecting diffuser is equal to (). Other color terms used in this standard shall be in accordance with the provisions of GB/T 5698. 4 Color measurement method
4.1 Non-fluorescent color
Spectral photometric measurement of non-fluorescent color shall be in accordance with GB/T 3979-1997, and calculate the three-stimulus value X, YZ or X, Y.Zn.
The direct reading (colorimeter) method for the non-fluorescent color is measured in accordance with 7-2 of B/T3979-1997, and the three-stimulus value X, YZ or X, YZ is directly measured:
4.2 Fluorescent color
The harmonic photometric measurement of fluorescent color and the direct reading (colorimeter) method for the stimulation value are measured in accordance with GB/T9340. Approved by the State Administration of Quality and Technical Supervision on May 14, 1999 and implemented on December 1, 1999
5 Method for measuring whiteness
5.1 Non-fluorescent colors
GB/T 177491999
For the measurement of whiteness of non-fluorescent colors, the three stimulus values ​​X, Y, Z or X, Y10.Z1 shall be measured in accordance with the provisions of 4.1, and the whiteness W or W and the hue index Tw or Tw.10 shall be calculated in accordance with the provisions of Chapter 6
5.2 Fluorescent colors
For the measurement of whiteness of fluorescent colors, the three stimulus values ​​X, Y, Z or X, Y10.Z1 shall be measured in accordance with the provisions of 4.2, and the whiteness W or W. and the hue index Tw or Tw.10 shall be calculated in accordance with the provisions of Chapter 6
6 Method for calculating whiteness and light hue index
6.1 Calculation method of whiteness
Whiteness W or WL is calculated according to the following formula (1) or formula (2): W = Y + 800(z— ±) +1 700(y—y)Wg=Y10+ 800(a0—z1) +1700(3..1-y) In the formula, W
Tu.10, Yn.10
whiteness of the sample in the XYZ colorimetry system;
Y value of the sample in the three stimulus values ​​of the XYZ colorimetry system;
y value of the sample in the three color coordinates of the XYZ colorimetry system: I.3 value of the totally reflecting diffuser in the three color coordinates of the XY2 colorimetry system (Table 1); whiteness of the sample in the X1Y1.Z1e colorimetry system, Y1 value of the sample in the three stimulus values ​​of the X1.Y.Z1 colorimetry system: 1oo value of the sample in the three color coordinates of the XYZ1e colorimetry system; 2a value of the totally reflecting diffuser in the three color coordinates of the XiYuzu colorimetry system (see Table 1). 6.2 Calculation method of light tone index
The light tone index Tw or Tw,1c is calculated according to the following formula (3) or formula (4): T = 1 000(a, — ) - 650(3% — y)7w10 = 900(r..10—21c)— 650(3a.10—y1) In the formula, Tw-
-the light hue index of the sample in the XYZ colorimetry system, the t,y values ​​of the sample in the three color coordinates of the XYZ colorimetry system, and the y values ​​of the completely reflecting diffuser in the three color coordinates of the XYZ colorimetry system (Table 1); T,10--the light hue index of the sample in the X121 colorimetry system; 1010
T.,10.y..10
the 20.Jia value of the sample in the three color coordinates of the X1oY1Z1a colorimetry system, and the t,y values ​​of the completely reflecting diffuser in the three color coordinates of the XZ colorimetry system (see Table 1). Table 1 Three stimulus values ​​and three color coordinates of a completely reflecting diffuser under D standard illumination
XYZ colorimetry system
....(2)
X1rYZ colorimetry system
6.3 Scope of application of whiteness and hue index GB/T17749—1999
Table 1 (end)
This standard is the evaluation formula for neutral white recommended by CIE. The experimental basis of the light color formula is shown in Figure 1. The equal light color line is a parallel line close to the main wavelength of 466 Ⅱ m. The whiteness formula is not applicable to color samples. The whiteness W and W light hue index Tw in formulas (1) to (4) are respectively applicable to the following sample samples: 40W (5Y280) or 40W (5Yi-280)
- 3.0 Tw + 3.0 or -- 3.0 < Tw,10 ≤+ 3.07 Method of expressing whiteness
7.1 Expression in the library
Whiteness is expressed by the numerical values ​​of W and Tw, or Wm and Tw calculated in accordance with the provisions of Chapter 6. The figures are rounded to one decimal place. 7.2 Additional records
Additional records of the measured values ​​include: the measuring instrument, the measuring method, the geometric conditions of lighting and detection, etc. . B
Figure 1, the dominant wavelength of white color is 466nm
with 460nm and 470nm as the boundary, the distribution is 620
7 nm
blue light whiteness formula
where. W..R*
GB/T 17749-1999
Appendix A
(Appendix for reference)
other main whiteness formulas currently used
WI - R - KIER(A)F(A)A
...(A1)www.bzxz.net
blue light whiteness, the instrument spectrum response is the reflection number measured under the blue light condition with effective width 457 In L2 nn and half width 44 nm;
normalization coefficient.KF(X
Spectral reflectance factor of the sample;
Relative spectral response distribution of the blue light whiteness meter (Table A1): F(a)
-Wavelength interval for calculating whiteness:
Table A1 Relative spectral component distribution F(a) given by the light source, optical system and detector of the blue light whiteness meter
wavelength a, rm
Hunter whiteness formula
W——Hunter whiteness;
L--Hunter brightness:
α, b-Hunter characteristic index.
Dumpling length a, nm
W 100[(100 Ly\ +a+-
W = - 36
（1）When the whiteness is measured using a 2 degree viewing angle and a standard illuminant (, the formula is: Z=10Y
4 =17.2(1.02X
5 - 7.0(Y - (0.8472)
（A2）
GB/T 17749—1999
where: X, Y, Z - the three stimulus values ​​of the sample in the XYZ colorimetric system. (2) When the whiteness is measured using a 10° viewing angle and a standard illuminant D,, the formula is: L =1ort
a = 17.2(1.055X:u - Ym)
6.7(rm - (.932z.)
where: Xi, YinZi sample in X.nY1Z, colorimetric system tristimulus value. A3Z White Magic Formula
2° field of view · standard illuminant C,
W:= 0. 847z
10° field of view, standard illuminant [)s: Wz.10=0.932Z1 formula +: W..Wx15
-2 whiteness!
·z value
sample's tristimulus value
1Ganz linear whiteness formula
W- DY I Fr+Qy+C
Y——one of the two stimulus values ​​of the sample, Y value; - the three color coordinates of the sample, 3 values;
coefficients determined according to the whiteness requirements of the sample, (A4)
.- (A6)
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