ASTM D6961/D6961M-09(2021)

5.1?Few standards exist to objectively judge flax quality. Color is an important factor in the quality of flax fiber. Natural variations in raw flax fiber, various processing steps, fiber blending, and a wide range of end uses contribute to the need for a standard method of objectively measuring the color of flax fiber. Spectrophotometic data provide an accurate, precise determination of the color of flax fiber. Colorimetric data are obtained through specimen measurement by combining specimen spectral data with data representing a CIE standard observer and a CIE standard illuminant, as described in Practice E308.

5.2?If there are differences of practical significance between reported test results for two (or more) laboratories, comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, use the samples for such a comparative test that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing and randomly assigned in equal numbers to each laboratory. The results from the laboratories involved should be compared using a statistical test for unpaired data, a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results for that fiber sample type must be adjusted in consideration of the known bias.

1.1?This test method covers the instrumental color measurement of flax fiber.

1.2?The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.3?This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.