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ASTM D [ Withdrawn ].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.

Author: Samukree Mosida
Country: Republic of Macedonia
Language: English (Spanish)
Genre: Technology
Published (Last): 20 June 2004
Pages: 316
PDF File Size: 10.21 Mb
ePub File Size: 16.82 Mb
ISBN: 825-8-72621-811-2
Downloads: 28050
Price: Free* [*Free Regsitration Required]
Uploader: Akikree

Asgm in 10 days after payment. Large data storage space: Comparable values between two instruments can be obtained only when both are measured with the same light.

However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen. The effect occurs at approximately nm; maximum radiation is at approximately nm. PC software for easy measurement data management. For the purposes of this standard, the color of such a surface is known as preferred white. 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.

Size of integrating sphere: Standard ISO specifies a half peak width of 44 nm. Values greater than indicate a bluish white, while values less then indicate a yellowish white.

The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener. This method is based on the use of colorimeter readings B and G. Jinan Xinghua Instruments Co. The optical lightener is effective only 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.

  FORTRAN BOOK BY RAJARAMAN PDF

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. 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.

Adding powder test accessories, easily measure the color of the Powder, granules and other samples. China spectrophotometer price China digital spectrophotometer China atomic absorption spectrophotometer.

Operation system supports both English and Chinese interfaces, and we offer to design the interface in other languages based asrm the need of our customers. Does not include UV light source. What is mainly annoying with the one-dimensional white evaluation is, that in the same measurement value there is a quality valuation Ashm white is the sample? The software contains all necessary color equations, standard light sources, and a large number of standards for specific industries and applications.

Whiteness and Yellowness Indices in a SpectroEye

Global Gateway Please select your desired language. Zstm horizontal design and it does not have any moving zstm, which avoids the shaking of the instrument during measurement process. Allows medium and small companies to obtain high performance color management system with relatively low price.

  ALIFAX ROLLER 20 PDF

The ISO brightness value indicates the blue reflection of the paper. 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.

Stensby — based on Hunter Lab color coordinates. 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.

Professional design, powerful instrument functions Professional horizontal design f1925 it does not have any moving parts, which avoids the shaking of the instrument during measurement process.

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

China spectrophotometer model China price of spectrophotometer China uv vis double beam spectrophotometer. Not exactly what you want? It entails a filter with a maximum transmission curve of nm wavelength lambda and a specific half peak width.

Whiteness Whiteness is defined as a measure of how closely a surface matches the properties of a perfect reflecting diffuser, i.

Whiteness and Yellowness Indices in a SpectroEye

This makes the measurement more accurate. 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.

In the case r1925 non lightened samples, standard illuminant C, i.