4.1 This test method is designed to measure the vertical distance between any two levels on the face of the flooring, that is, between any two flat areas, between a flat area and any part of a textured area, or between two textured areas. This vertical distance may be of interest in itself or it may be applied to the questions of: (1) how much of the thickness of the flooring is available before the pattern is destroyed; or (2) how deep the depressed areas must be before valley printing ink is not walked on in normal traffic.

1.1 Two important characteristics involved in the manufacture of resilient flooring relate to the smoothness of the wear surface and the hardness of the layers under the wear surface. The surfaces may vary from completely textured areas to portions that are flat but separated by textured areas. This test method covers flooring with these interrupted wear surfaces which are not supported by soft, cushioned layers.

1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that 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.