Introduction to ASTM E308
The CIE system is used to calculate object colors according to ASTM E308 Standard Practice. Illuminant spectral power distributions and color-matching functions have been specified by the CIE since 1931, and tristimulus weighting factors have been gathered in many literature sources. By standardizing tristimulus computing techniques, the standard seeks to lessen data discrepancies brought on by various wavelength choices and truncation techniques. Conventions were proposed by Foster et al. in 1970, and Stearns’ extensive tables came next. MaTestLab is one of the best testing service providers, with the best network of testing laboratories in the USA to carry out ASTM E308 tests for our clients. Procedures for situations when spectral data is scarce or where measurement intervals are larger than advised and bandpass correction for instruments with presumed triangular spectral bandpass forms are also covered in ASTM E308.
ASTM E308 Test Method
| Apparatus Setup | Spectrophotometer, light source (CIE standard illuminants), observer selection (CIE standard observers), and spectral data measurement instrument. |
| Test Procedure | The CIE standard illuminant and observer are selected, and the measurement intervals (1, 5, 110, or 20 nm) are chosen. Spectral data correction for bandpass dependence is ensured. For calculations, tristimulus weighting factors are used. Tristimulus values are calculated by summing the products of weighting factors and spectral data. The results are converted to CIE color spaces like CIELAB and CIELUV. |
ASTM E308 Test Specimens
| Specimen Details | Object color, composition, and surface characteristics are chosen as per the guidelines. |
| Specimen Preparation | The specimens are cleaned, polished, and adjusted according to the conditions mentioned in the test. |
| Specimen Dimensions | The dimensions are set by the ASTM specification. |
ASTM E308 Test Results
ASTM E308’s importance stems from its ability to provide numerical parameters for color stimuli, which are helpful for production control, research, color specification, and tolerance setting. The test is helpful for several sectors, including textiles, paints, plastics, and printing, since it matches color stimuli, detects color discrepancies, and converts stimulus values into uniform color scales like CIELAB and CIELUV.
Tests Related to ASTM E308
ASTM E308 is a test just like ASTM E144, which is an ASTM specification that helps to provide safe operation for oxygen combustion levels to identify sulfur and carbon from various ores, and ASTM E269, which uses X-ray fluorescence spectroscopy to analyze thorium and uranium in soil.
