What specification applies to the scraping edge of a straight edge used in compaction tests?

The specification for the thickness of the scraping edge of a straight edge used in compaction tests is that it shall be no thicker than 1/8". This requirement is established to ensure accuracy and precision when measuring the surface of compacted soil or other materials. A thinner edge allows for a more effective scraping and leveling action, which is essential for obtaining reliable measurements in compaction tests.

Using a thicker edge, such as 1/4" or 1/2", could result in inaccuracies because it may not rest flat against the surface being measured or may not effectively reach low spots, leading to an erroneous assessment of the compaction levels. Similarly, a thickness of 1/16" may not provide the required durability for repeated use in testing. By adhering to the 1/8" specification, the straight edge can effectively fulfill its function in precise compaction tests.