意义及用途
5.1 This practice should only be used to compare samples of the same material and the same general appearance. 例如, a range of specimens to be compared should have roughly similar lustre, texture and (if not opaque) thickness and semi-transparency.
5.2 For yellowness measurements, this practice is limited to samples whose main wavelength is in the range 570 to 580nm or whose Munsell hue is approximately 2.5GY to 2.5Y. For whiteness measurements, this practice is limited to samples with Munsell values greater than 8.3 (CIEY greater than 65) and Munsell chromaticity no greater than 0.5 (B tone) and Munsell chromaticity no greater than 0.5 (Y tone 0.8) and all other tones of 0.3 (看 3.3.1).
5.3 The combination of measurement and calculation that results in a yellow or white index is a psychophysical process, 那是, the specified procedure is designed to provide numbers relevant to visual estimates made under specific typical observation conditions. Since visual observation conditions vary widely, users should compare the calculated index with visual estimates to ensure applicability. Some standards that address color and chromatic aberration vision estimation are Practices D1535, D1729, E1360, and E1541, as well as guidelines E1499.
5.4 This practice does not include specimen preparation, a procedure that can have a significant impact on the amount measured. Typically, samples should be prepared and presented for measurement in a standard manner for the tests performed. Select enough samples or sample areas to provide average results representative of each sample under test. See Practice E1345.
Calculation of Yellowness Index and Whiteness Index Using Instrumental Color Coordinates
范围
1.1 This practice provides numbers associated with visual ratings of yellow or white for color specimens of white and near-white or colorless objects, viewed in daylight by observers with normal color vision. White textiles, paints and plastics are some of the materials that can be described by the yellow or whiteness index calculated in this way.
1.2 In order to perform a complete analysis of object color by a specified observer and a specified light source, three parameters need to be used. 然而, for near-white specimens, it is often useful to calculate a singular scale of yellowness or whiteness. This practice provides recommended equations for this scale and discusses their derivation and use, as well as the limits of their applicability (see also References (1) 2).
1.3 Values expressed in SI units shall be treated as standard values. 本标准不包含其他计量单位.
Calculation of Yellowness Index and Whiteness Index Using Instrumental Color Coordinates
1.4 本标准并非旨在解决所有问题, 如果有的话, 与其使用相关的安全问题. 本标准的使用者有责任建立适当的安全机制, 健康和环境实践，并在使用前确定监管限制的适用性.
1.5 本国际标准以《关于制定国际标准的原则的决定》中确立的国际公认的标准化原则为基础, Guidelines and Recommendations issued by the WTO Committee on Technical Barriers to Trade.