ASTM D7681-11R21 - Standard Test Method for Measuring Gradation of Glass Spheres Using a Flowing Stream Digital Image Analyzer

1.1 This test method covers the determination of the gradation (size distribution) of glass spheres used in pavement marking systems using a Flowing Stream Digital Analyzer. Typical gradations for pavement marking systems are defined in ranges from Type 0 through 5 in AASHTO M247-08.

1.2 This test method provides for the presentation of the size data in a variety of formats to the requirements of the agency pavement marking material specification. For most specifications the standard format is to present the size data as “Percent Retained” or “Percent Passing” relative to a series of standard US sieve sizes.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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.