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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The ISO brightness value indicates the blue reflection of the paper. For whiteness measurement, this practice is limited to specimens having Munsell value greater than 8. 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 adtm used with other illuminants; therefore the value shown will depend on the primary illuminant you have chosen. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as qstm of the standard.
Through our network of over 43, people in 1, laboratories and offices in countries, Intertek provides quality and safety solutions to a wide range of industries around the world. 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 according f313 ASTM E D was developed specifically for determining the yellowness of atsm, non-fluorescent, nearly colorless, transparent, nearly white translucent, or opaque plastics, as viewed under daylight lighting conditions.
Multiple samples should be measured and the readings averaged. For the purposes of this standard, the color of such a surface is known as preferred white.
Yellowness Index (YI) ASTM E
Inspection Validating the specifications, value and safety of your raw materials, products and assets. Standard ISO specifies a half peak width of 44 nm. Formally confirming that your products and services asstm all trusted external and internal standards. Because visual observing conditions can vary widely, users should compare calculated indices with visual estimates to ensure applicability.
It can also be applied to materials other than plastic fitting this description. Need help or have a question? 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
Stensby — based on Qstm Lab color coordinates. Testing Evaluating how your products and services meet and exceed quality, safety, sustainability and performance 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.
Certification Formally confirming that your products and services meet all trusted external and internal standards. 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.
Comparable values between two instruments can be obtained only when both are measured with the same light. Values greater than indicate a bluish white, while values less then indicate a yellowish white. It should be clear that the distribution of relative spectral radiation of the light on the sample during measurement plays an important role.
Yellowness Index (YI) ASTM E313
Global Reach Intertek is the industry leader with over 42, people in 1, locations in over countries. This method is based on the use of colorimeter readings B and G. 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.
For near-white specimens, however, it is often useful to calculate single-number scales of yellowness or whiteness. Assurance Enabling you to identify and mitigate the intrinsic risk in your operations, supply chains and business processes. In the case of non lightened samples, standard illuminant C, i. Evaluating how your products satm services meet and exceed quality, safety, sustainability and performance standards.
In general, specimens should be prepared and presented for measurement in the manner that is standard for the test being performed. Historical Version s – view previous versions of standard. Yellowness, as defined by ASTM Ehas been applied successfully to a variety of white or near-white materials, including paints, plastics, and textiles.
It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
For example, a series of specimens to be compared should have generally similar gloss, texture, and if not opaque thickness, and translucency. No other units of measurement are included in this standard. Test sample packaging, handling, and preparation preferably no cleaning can affect the test results by modifying the surface of 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. Some standards addressing the visual estimation of color and color difference are Practices DDEand Eand Guide E