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ASTM D [ Withdrawn ].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. However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen.
The software contains all necessary color equations, standard light sources, and a large number of standards for specific industries and applications. However, this also intensifies ISO brightness. Size of integrating sphere: Operation system supports both English satm Chinese interfaces, and we offer to design the interface in other languages based on the need of our customers.
Whiteness and Yellowness Indices in a SpectroEye
China spectrophotometer price China digital spectrophotometer China atomic absorption spectrophotometer. Yellowness, as defined by ASTM Ehas been applied successfully to a variety of white or near-white materials, including paints, asfm, and textiles.
Large data storage space: Professional horizontal design and it does wstm have any moving parts, which avoids the shaking of the instrument during measurement process. Stensby — based on Hunter Lab color coordinates. 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.
ASTM D1925, ASTM E313 Spectrophotometer
For the purposes of this standard, the color of such a surface is known as preferred white. 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. True color screen that includes all colors Work temperature range: Global Gateway Please select your desired language. PC software for easy measurement data management.
Standard ISO specifies a half peak width of 44 nm. Yellowness according to ASTM E D was developed specifically for determining the yellowness of homogeneous, d11925, nearly colorless, transparent, nearly white translucent, or opaque plastics, as viewed under daylight lighting conditions. Adding powder test accessories, easily measure the color of the Powder, granules and other samples.
Jinan Xinghua Instruments Co.
Values greater than indicate a bluish white, while values less then indicate a yellowish white. This method is based on the use of colorimeter readings B and G. The ISO brightness xstm indicates the blue reflection of the paper. It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role. In the case of non lightened samples, standard illuminant C, i.
This makes the measurement more accurate. It can also be applied to materials other than plastic fitting this description. 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.
ASTM D – 70() Test Method for Yellowness Index of Plastics (Withdrawn )
Does not include UV light source. The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener. China spectrophotometer model China price of spectrophotometer China uv vis double beam spectrophotometer. 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. 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?
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. Standard illuminant D65 must be used for measurement of optically lightened papers.
Whiteness and Yellowness Indices in a SpectroEye
The optical lightener is effective only due to the UV radiation. The indices can be calculated, rounded, and adjusted in the last retained significant digit to minimize the residual error in the white point values. 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. The effect occurs at approximately nm; maximum radiation is at approximately nm.