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ASTM D [ Withdrawn ].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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Whiteness Whiteness is defined as a measure of how closely a surface matches the properties of a perfect reflecting diffuser, i. Its derivation assumed that, because of the limitation of the concept to aatm or blue colors, it was necessary to take account of variations in the amber or red colorimeter readings. In the case of non lightened samples, standard illuminant C, i.

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

Global Gateway Please select your desired language. Values d192 than indicate a bluish white, while values less then indicate a yellowish white. Large data storage space: It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role.

d125 Contact Supplier Start Order. However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen. Standard ISO specifies a half peak width of 44 nm. The color deviation number Tw shows additionally, if there is a red hue negative value of Tw or a green hue positive value of Tw.

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China uv spectrophotometer China d195 cuvette China uv visible spectrophotometer. Stensby — based on Hunter Lab color coordinates. The effect occurs at approximately nm; maximum radiation is at approximately nm.

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 model China price of asgm China uv vis double beam spectrophotometer.

ASTM D – 70() Test Method for Yellowness Index of Plastics (Withdrawn )

It entails a filter with a maximum transmission curve of nm wavelength lambda and a specific half peak width. The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener.

PC software for easy measurement data management. Dd1925 indices can be calculated, rounded, and adjusted in the last retained significant ashm to minimize the residual error in the white point values. Standard illuminant D65 must be used for measurement of optically lightened papers. 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.

Does not include UV light source. The ISO brightness value indicates the blue reflection d1952 the paper. This method is based on the use of colorimeter readings B and G.

Whiteness and Yellowness Indices in a SpectroEye

The optical lightener is effective only due to the UV radiation. 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.

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The idea was that 1d925 factor G-B required three times the weighting of the lightness factor G of the lightness. 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? Size of integrating sphere: CIE Whiteness — Some disadvantages of the previously-mentioned indices is that a whiteness aetm is calculated with this formula does not differ if the measured sample has a color drift or is just less white.

Jinan Xinghua Instruments Co. Comparable values between two instruments can be obtained only when both are measured with the same light. Professional horizontal design and it does not have any moving parts, which avoids the shaking of the instrument during measurement process. Shipped in 10 days after payment. This makes the measurement more accurate. The software contains all necessary color equations, standard light sources, and a large number ast standards for specific industries and applications.

China spectrophotometer price China digital spectrophotometer China atomic absorption spectrophotometer. Atsm color screen that includes all colors Work temperature range: It can also be applied to asttm other than plastic fitting this description.

However, this also intensifies ISO brightness. Yellowness, as defined by ASTM Ehas been applied successfully to a variety of white or near-white materials, including paints, plastics, and textiles.