4.1 The Horizontal Pull Slipmeter³ is a laboratory and field instrument designed to provide information about the slip index characteristics between walkway surfaces and a test foot material under dry conditions only. The HPS can not be used on wet surfaces. Slip index can be affected by surface roughness, presence of water, contaminants such as grease and other foreign materials, and floor surface wear over time. Slip index, as determined by the HPS, most likely will not give useful information for evaluating liquid contaminated surfaces, and therefore, will not provide an effective assessment of a potential slipping hazard on a walkway surface under these conditions.

4.2 The value reported by the Horizontal Pull Slipmeter is called the slip index. Slip index is ten times the static coefficient of friction. For example, a static coefficient of friction of 0.4 is displayed by a slip index of 4.0 when measured by the Horizontal Pull Slipmeter.

4.3 The HPS can be used on inclined surfaces. No adjustment for slope is needed for measurements in the direction perpendicular to the slope and when averaging four measurements at one location taken according to step 10.14.