ASTM E Calculating Yellowness and Whiteness Indices from Instrumentally. Measured Color Coordinates. This practice provides numbers that correlate. Yellowness indices are used chiefly to measure these types of degradation. Yellowness Index per ASTM Method E is calculated as follows. To begin the ASTM D is a now obsolete Yellowness Index specification that is locked to calculate only using C/2 (illuminant C, 2deg.
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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 d313 preferred white or colorless towards yellow. Yellowness Index is a number calculated from spectrophotometric data that describes the change in color of a test sample from clear or white to yellow.
Whiteness and Yellowness Indices in a SpectroEye
Select enough specimens or specimen areas to provide an average result that is representative of each sample to be tested. Standard illuminant D65 must be used for measurement of optically lightened papers. No other units of measurement are included in this standard.
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. 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.
Since YI testing is often a series of comparative measurements over extended periods of time, these factors should be defined and documented prior to any testing. Yellowness, w313 defined by ASTM Ehas been applied successfully to a variety of white or near-white materials, including paints, plastics, and textiles.
In the case of non lightened samples, standard illuminant C, i.
Yellowness Index (YI) ASTM E
Multiple samples should be measured e3313 the readings averaged. Historical Version s – view previous versions of standard Translated Version s: 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. Auditing Consulting Sourcing Training.
Historical Version s – view previous versions of standard. 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.
Whiteness and Yellowness Indices in a SpectroEye
The idea was that chromaticity factor G-B required three times the weighting of the lightness factor G of the lightness. Global Gateway Please select your desired language. Some standards addressing the visual estimation of color and color difference are Practices DDEand Eand Aetm E Stensby — based on Hunter Lab color coordinates.
White textiles, paints, and plastics are a few of the materials that can be described by the indices of yellowness or whiteness calculated by this practice. Inspection Validating the specifications, value and safety of your raw materials, products and assets. Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards. The effect occurs at approximately nm; maximum radiation is at approximately nm.
Whiteness Whiteness is defined as a measure of how closely a surface matches the properties of a perfect reflecting diffuser, i. Standard ISO specifies a half peak width of 44 nm. This practice provides recommended equations for such scales and discusses their derivations and uses, and limits to their applicability see also Ref 1 2. For near-white specimens, however, it is often useful to calculate single-number scales of yellowness or whiteness.
Send us a request Need help or have a question? Link to Active This link will always route to the current Asrm version of the standard. 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?
Testing Evaluating how your products and services meet and exceed quality, safety, e31 and performance standards. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
However, this also intensifies ISO brightness.
Yellowness Index (YI) ASTM E313
In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed. Assurance Testing Inspection Certification. For the purposes of this standard, the color of such a surface is known as preferred white. Values greater than indicate a bluish white, while values less then indicate a yellowish white. Global Reach Intertek is the industry leader with over 42, people in 1, locations in over countries. It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role.
Validating the specifications, value and safety of your raw materials, products and assets.
However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have r313. Need help or have a question? Send us a request Wilton UK: