5.1 Many competent measurement laboratories comply with accepted quality system requirements such as ISO 9001, QS 9000, or ISO 17025. When using standard test methods, the measurement results should agree with those from other similar laboratories within the combined uncertainty limits of the laboratories’ measurement systems. It is for this reason that quality system requirements demand that a statement of the uncertainty of the test results accompany every test result.

5.2 Preparation of uncertainty estimates is a requirement for laboratory certification under ISO 17025. This practice describes the procedures by which such uncertainty estimates may be calculated.

1.1 This practice describes a protocol to be utilized by measurement laboratories for estimating and reporting the uncertainty of a measurement result when the result is derived from a measurand that has been obtained by spectrophotometry.

1.2 This practice is specifically limited to the reporting of uncertainty of color measurement results that are reported as color-differences in ΔE format, even though the measurement itself may be reported in other units such as percent reflectance or transmittance.

1.3 The procedures defined here are not intended to be applicable to national standardizing laboratories or transfer laboratories.

1.4 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.

1.5 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.