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Subject: to improve weathering как бы вы перевели фразу to improve weathering? спасибо
Background—The currently recommended equation for the calculation of yellowness index is derived from an equation due to Hunter in 1942: YI = (A - B)/G, where A, B, and G are, respectively, amber or red, blue, and green colorimeter readings. Another version, used in the 1940s to 1960s for transparent plastics , was based on transmittances near the ends of the visible wavelength region: YI = 100(T680 - T 420)/T560 (with a factor of 100 introduced to give values of YI near unity). This equation failed to account correctly for differences in the spectral transmittance curves of such plastics, especially after the adoption of ultraviolet light absorbers to improve weathering, and was soon abandoned. When, in 1957, ASTM solicited new equations for calculating yellowness indices, Hunter's equation was converted into CIE tristimulus value form by using Hunter's approximate relations between colorimeter readings and those tristimulus values; the resulting equation, YI = 100(1.28X - 1.06Z)/Y, was adopted for use in Test Method D 1925 in 1962.
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