ASTM D1925 PDF

ASTM D [ Withdrawn ]. Standard Test Method for Yellowness Index of Plastics. standard by ASTM International, 01/22/ View all. wnessIndex was developed for the definition of the Yellowness of homogeneous, non-fluorescent, almost. Yellowness – ASTM D A measure of the yellowing of a plastic, such as might occur after long-term exposure to light. The deviation in chroma from.

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What is mainly annoying with the one-dimensional white evaluation is, that in the same measurement value there is a quality valuation How white is the sample? However, this also intensifies ISO brightness. Stensby — based on Hunter Lab color coordinates. In the case of non lightened samples, standard illuminant C, i. The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener. CIE Whiteness — Some disadvantages of the previously-mentioned indices is that a whiteness that is calculated with this formula does not differ if the measured sample has a color drift or is just less white.

The effect occurs at approximately nm; maximum radiation is at approximately nm. The optical lightener is effective astj due to the UV radiation. The idea was that chromaticity factor G-B required three times the weighting of the lightness factor G of the lightness. Operation system supports both English and Chinese interfaces, and we offer to design the interface in other languages based on the need of our customers.

It can also be applied to materials other than plastic fitting this description. Comparable values between two instruments can be obtained only when both are measured with the same light.

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Standard ISO specifies a half peak width of 44 nm.

Shipped in 10 days after payment. The indices can be calculated, rounded, and adjusted in the last retained significant digit to minimize the residual error in the white point values.

Jinan Xinghua Instruments Co. Large data storage space: Allows medium and small companies to obtain high performance color management system with relatively low price. Whiteness and Yellowness Indices in a SpectroEye Yellowness Yellowness is defined as a measure of the degree to which the color of a surface is shifted from preferred white or colorless towards yellow.

China spectrophotometer price China digital spectrophotometer China atomic absorption spectrophotometer. True color screen that includes all colors Work temperature range: PC software for easy measurement data management. It entails a filter with a maximum transmission curve astk nm wavelength lambda and a specific half peak width.

Yellow Index YI caculation standard E D_图文_百度文库

However, the equation is commonly used with other illuminants and observer functions, therefore the value shown will depend on the primary illuminant and the observer function you have chosen. Does not include UV light source. This method is based on the use of colorimeter readings B and G. Not exactly what you want? Its derivation assumed that, because of the limitation of the concept to yellow or blue colors, it was necessary to take account of variations in the amber or red colorimeter readings.

Professional design, powerful instrument functions Professional horizontal design and it does not have any moving parts, which avoids the shaking of the instrument during measurement process. For the purposes of this standard, the color of such a surface is known as preferred white. Adding powder test accessories, easily measure the color of the Powder, granules and other samples.

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Yellowness according to ASTM E D was developed specifically for determining the yellowness of homogeneous, non-fluorescent, nearly colorless, transparent, nearly white translucent, or opaque plastics, as viewed under daylight lighting conditions.

Values greater than indicate a bluish white, while values less then indicate a yellowish white.

It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role. The software contains all necessary color equations, standard light sources, and a large number of standards for specific industries and applications. Professional horizontal design and it does not have any moving parts, which avoids the shaking of the instrument during measurement process.

Global Gateway Please select your desired language. Contact Supplier Start Order. Size of integrating sphere: Standard illuminant D65 must be used for measurement of optically lightened papers.

Whiteness and Yellowness Indices in a SpectroEye

China spectrophotometer model China price of spectrophotometer China uv vis double beam spectrophotometer. This makes the measurement more accurate. However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen.