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ASTM D [ Withdrawn ].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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The software contains all necessary color equations, standard light sources, and a large number of standards for specific industries and applications.

Values greater than indicate a bluish white, while values less then indicate a yellowish white. However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have zstm.

ASTM D1925, ASTM E313 Spectrophotometer

The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener. For the purposes of this standard, the color of such a surface is known as preferred white. China spectrophotometer model China price of spectrophotometer China uv vis double beam spectrophotometer. 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.

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. 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. In the case of non lightened samples, standard illuminant C, i.

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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? Standard ISO specifies a half peak width of 44 nm. It entails a filter with a maximum transmission curve of nm wavelength lambda and a specific half peak width.

The idea was that chromaticity factor G-B required three times the weighting of the lightness factor G of the lightness. 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.

Adding powder test accessories, easily measure the color of the Powder, granules and other samples. 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. This method is based on the use of colorimeter readings B and G. Not exactly what you want? However, this also intensifies ISO brightness.

Global Gateway Please select your desired language. China uv spectrophotometer China spectrophotometer cuvette China uv visible spectrophotometer. True color screen that includes all colors Work temperature range: PC software for easy measurement data management. Whiteness Whiteness is defined as v1925 measure of how closely a surface matches the properties of a perfect reflecting diffuser, i. Does not include UV light source. Yellowness according to ASTM E D adtm 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.

It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role.

ASTM-D | Test Method for Yellowness Index of Plastics (Withdrawn ) | Document Center, Inc.

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

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Yellowness, as defined by ASTM Ehas been asttm successfully to a variety of white or near-white materials, including paints, astmm, and textiles. The ISO brightness value indicates the blue reflection of d19225 paper.

Contact R1925 Start Order. Stensby — based on Hunter Lab color coordinates. Standard illuminant D65 must be used for measurement of optically lightened papers. China spectrophotometer price China digital spectrophotometer China atomic absorption spectrophotometer. Large data storage space: The effect occurs at approximately nm; maximum radiation is at approximately nm.

Comparable values asstm two instruments can be obtained only when both are measured with the same light. Allows medium and small companies to obtain high performance color management system with relatively low price.

This makes the measurement more accurate. Jinan Xinghua Instruments Co. Professional horizontal design and it does not have any moving parts, which avoids the shaking of the instrument during measurement process.

The optical lightener is effective only due to the UV radiation. It can also be applied to materials other than plastic fitting this description. Size of integrating sphere: