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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Referenced Documents purchase w313 The documents listed below are referenced within the subject standard but are not provided as part of the standard. Whiteness Whiteness is defined as a measure of how closely a surface matches the properties of a perfect reflecting diffuser, i. In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed.
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.
Whiteness and Yellowness Indices in a SpectroEye
This method is based on the use of colorimeter readings B and G. However, the equation is commonly used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen.
It entails a filter with a maximum transmission curve of nm wavelength lambda and a specific half peak width. 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 should be clear that the distribution of relative spectral radiation of the astk on the sample during measurement plays an important role.
Test sample packaging, handling, and preparation preferably no cleaning can affect the test results by modifying the surface of the sample. Send us a request Wilton UK: Stensby — based on Hunter Lab color coordinates. Send us a request Need help or have a question? Formally confirming that your products and services meet all trusted external and internal standards. 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.
The idea was that chromaticity factor G-B required three times the weighting of the lightness factor G of the lightness. Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance standards.
No other units of measurement are included in this standard. After specifying the illuminant, observer angle, and the reference color, the test sample is inserted into the specimen holder, and the spectrophotometer takes the reading.
It can also be applied to materials other than plastic fitting this description. Standards can be obtained from appropriate standard authorities. Certification Formally confirming that your products and services meet all trusted external and internal standards. 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.
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Yellowness Index (YI) ASTM E313
Historical Version s – view previous versions of standard. Standard illuminant D65 must be used for measurement of optically lightened papers. Assurance Testing Inspection Certification. This practice provides recommended equations for such scales and discusses their derivations and uses, and limits to their applicability see also Ref 1 2. The ISO brightness value indicates the blue reflection of the paper.
For the purposes of this standard, the color of such a surface is known as preferred white. Link to Active This link will always route to the current Active version of the standard. However, this also intensifies ISO brightness. 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.
Auditing Consulting Sourcing Training. What is mainly annoying with the one-dimensional white evaluation is, that in the same measurement value there is a quality valuation How white atm the sample? The optical lightener is effective only due to the UV xstm. Because visual observing conditions can vary widely, users should compare calculated indices with visual estimates to ensure applicability.
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. Need help or have a question?
Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes. 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. Validating the specifications, value and safety of your raw materials, products and assets.
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.
Inspection Validating the specifications, value and safety of your raw materials, products and assets. For near-white specimens, however, it e3313 often useful to calculate single-number scales of yellowness or whiteness.
The greater the illumination intensity in the UV-range, the more the greater the detection of the optical lightener. In the case of non lightened samples, standard illuminant C, i.
Whiteness and Yellowness Indices in a SpectroEye
Multiple samples should be measured and the readings averaged. The indices can be calculated, rounded, and adjusted in the last retained significant digit to minimize the residual error in the white point values. Global Reach Intertek is the industry leader with over 42, people in 1, locations in over countries. Yellowness, as defined by ASTM Ehas been applied successfully to a variety e3313 white or near-white materials, including paints, plastics, and textiles. For example, a series of specimens to be compared should have generally similar gloss, texture, and if not opaque thickness, and translucency.
Some standards addressing the visual estimation of color and color difference are Practices D asmt, DEand Eand Guide E