This standard specifies the conditions and methods for the determination of whiteness of daily-use ceramics and ceramic raw materials. This standard is applicable to the determination of whiteness of daily-use ceramics and ceramic raw materials. QB/T 1503-1992 Method for determination of whiteness of daily-use ceramics QB/T1503-1992 Standard download decompression password: www.bzxz.net

Light Industry Standard of the People's Republic of China
Determination Method of Whiteness of Daily-use Ceramics
1 Subject Content and Scope of Application
This standard specifies the determination conditions and methods of whiteness of daily-use ceramics and ceramic raw materials. This standard is applicable to the determination of whiteness of daily-use ceramics and ceramic raw materials. 2 Reference standards
GB/T3977 Method of expressing color
GB/T3978 Standard illuminant and lighting observation conditionsGB/T 3979
Method of measuring object color
Color terms
GB/T 5698
General rules for self-test methods for building materials and non-metallic mineral productsGB/T 5950
GB/T 7921
Uniform color space and color difference formula
GB/T9086 Ceramic standard white plate for colorimetry and photometryGB/T9087 Powder standard white plate for colorimetry and photometry3 Definitions and methods
QB/T 1503---1992
3.1 In the visible spectrum, the whiteness of an ideal surface with a spectral diffuse reflectance of 100% is 100 degrees, and the whiteness of an absolute black surface with a spectral diffuse reflectance of zero is zero degrees.
3.2 Using the conditions specified in this standard, measure the three stimulus values ​​of the sample, first calculate the hue angle, and then use the specified color separation type to calculate its chromaticity and chromaticity. bZxz.net
4 Instruments
4.1 Instruments that meet the following conditions can be used in this standard. Use the CIE1964XYZ supplementary colorimetric system; a.
b. Use the CTE standard illuminant Des, and the standard lighting observation conditions are 0/d (vertical/diffuse) or d/0 (diffuse/vertical), 0/d is the arbitration condition:
The indication error of the whiteness measurement is not greater than 1.5 degrees. 4.2 Powder sample press
4.3 Standard white plate and working white plate
Whose whiteness value should be greater than 87 degrees:
Office. Working whiteness is a glazed white ceramic plate with a flat surface, no scratches, no cracks and no contact points. Its whiteness value should be around 80 degrees. It can be calibrated with a standard white plate when necessary. Standard white plates and working white plates must be calibrated regularly by the national metrology department or a technical organization authorized by the state. Approved by the Ministry of Light Industry of the People's Republic of China on June 8, 1992 and implemented on February 1, 1993
5 Test specimens
5.1 Powder test specimens
QB/T1503-
5.1.1 Take samples according to the sampling methods specified in the relevant product standards. Before the measurement, the sample should be sieved with a pore size of 0.104mm, dried at 105~110 (1h, placed in a desiccator and cooled to room temperature for use. 5.1.2 During the measurement, a certain amount of powder is injected into the powder sample press and pressed into a sample plate with a flat surface, no cracks and no defects. 5.2 Daily ceramic sample
5.2.1 Three samples, the size of the flat surface should meet the measurement requirements of the instrument probe. 5.2.2 The surface of the sample to be measured must be clean, flat, without color decoration, cracks and other scratches. 6 Measurement steps
6.1 Preheat and stabilize the instrument according to the instrument's operating procedures. 6.2 Calibrate the instrument with a working white board.
6.3 The surface of each sample should be measured three times.
7 Calculation formula
7.1 Calculate the arithmetic mean of the three stimulus values ​​of each sample: X=(X +X, + =(X+Y+Z)/3
=(Y+Y,+Y)/3
z = (Z + Z + Z.>/3
wherein: X}, X2X--X stimulus values ​​measured three times; YY.Y Y stimulus values ​​measured three times,
Z..2..Z~--Z stimulus values ​​measured three times; Wen, Y, Z..·the average value of the three stimulus values ​​of the sample. 7.2 Based on the obtained XY,2 values, calculate the chromaticity coordinates and chromaticity index: -X/(X++z)
J =Y/(X+Y+Z)
G* - 500[(X/X,)/3 - (Y/Y.)1a]6* = 200C(Y/Y.)13 - (Z/Z,)3) Where:
.---chromaticity coordinates:
α“6--average chromaticity index;
X., Y,, Z,---tristimulus values ​​of CIE1964 standard illuminant D5, X ==94.81, Y,-100.00, Z.-107.32. 7.3 Calculate the hue of the sample according to the 1976 CIEI.AB hue angle formula: hab = arcctg(b\/α\)
Wherein: hh hue angle;
When 135hu<315, it is bluish white;
When h<135°h≥315°, it is yellowish white. 7.4 Calculation of the whiteness value W of the sample by color tone
7.4.1 When 135°≤hab<315°, calculate the whiteness value of the bluish white sample according to formula (9): W = y -- 250(r - r.) + 3cy -- y)Wherein: rn-0. 313 8.y.0. 331 0.182
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·（5)
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QB/T 1503—1992
7.4.2When ha<135°hh≥315°, calculate the whiteness value of the yellow-white sample according to formula (10): W + 818(r — a,) -1365(y—y,)7.5Calculate the chroma Cb of the sample according to the 1976 CIELAB chroma formula: Cb* = (α*2 -+ b*2)1/2
8Result expression
8.1The whiteness of ceramic products is expressed in W.
8.2The chroma of ceramic products is expressed in Cab: When Ca≤4.0, it is achromatic;
When Ca4.0, it is colorful.
8.3 The hue of ceramic products is expressed in h:
When α>0.6≥0, h is between 0° and 90°, which is a red to yellow tone; when α*0, b\>0, hab is between 90° and 180°, which is a yellow to green tone; when α0, b*0.h is between 180° and 270°, which is a green to blue tone; when α>0.6<0, ha is between 270\ and 360°, which is a blue to red tone. Yellow
Chromaticity index diagram
8.4 The test results of the self-degree, hue angle and chroma of the sample are all retained to one decimal place. 9 Test report
The test report shall include the following contents:
Sample name, appearance characteristics and measurement location; a.
Hue angle, whiteness and chroma of three samples; b.
Other matters that should be explained in the measurement.
Additional explanation:
This standard is proposed by the Quality Standards Department of the Ministry of Light Industry. This standard is under the jurisdiction of the National Ceramic Standardization Center. This standard is drafted by the Ceramic Research Institute of the Ministry of Light Industry, and the Jiangxi Ceramic Research Institute participated in the drafting.
China Electric Power Corporation+
The main drafters of this standard are Zhang Jianping and Liu Hui. From the date of implementation of this standard, the former Ministry of Light Industry standard QB919-1983 "Method for Determination of Whiteness of Daily-use Ceramics" shall be abolished. (10)
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