ASTM D8424-21 PDF

SIGNIFICANCE AND USE 5.1 The nighttime retroreflective properties of pavement markings are known to improve driving safety. Retroreflective composite optics have been developed to improve retroreflectivity in dry and rainy wet conditions. For customers purchasing these materials it’s important to verify the consistency and performance. This guide provides a set of laboratory procedures which can be selected individually or together to evaluate lot-to-lot consistency of composite optics of the same type and manufacturer. These are not in-service performance procedures and don’t necessarily predict in-service performance. SCOPE 1.1 This guide presents a series of options for evaluating lot-to-lot consistency of retroreflective composite optics of the same type and form from the same manufacturer and does not recommend any specific course of action to be taken. This guide is meant to increase the awareness of information and approaches and is not meant to recommend any specific course of action per ASTM’s Form and Style for ASTM Standards definition for a Guide. 1.1.1 This guide does not determine lab procedure selection or acceptance criteria for a specific retroreflective composite optics product for its intended use. It is the responsibility of the manufacturer and customer to negotiate these details based on their specific needs. 1.1.2 This guide is not intended to predict in-service performance levels. 1.1.3 This guide is not intended for comparison of different types of composite optics or manufacturers of composite optics. 1.2 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 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.