Volume 25, Issue 1 (January 1997)
Comparison of Walkway Safety Tribometers: Part Two
Fall accidents generate large injury, morbidity, and mortality costs. Many falls are caused by pedestrian slips, which are in turn a result of one or a combination of factors: pedestrian, walkway surface, footwear, or environmental.
It is important to be able to quantify and characterize the slipperiness of walkways and shoe bottoms, both separately and in combination. There presently exist on the market many tribometers (walkway-friction measuring instruments); different tribometers do not necessarily give the same results under identical conditions.
In the summer of 1991, ASTM Committee F-13 on Safety and Traction for Footwear organized a workshop at Bucknell University, Lewisburg, PA to compare nine tribometers against each other and against a force plate, which measures ground-reaction forces.
Briefly, we found that different tribometers gave different results. An earlier paper contained results of data aggregated by tribometer. It appeared that the differences were at least in part a result of the fact that the tribometers measured different types (mechanisms or models) of friction. The force plate “saw” and mimicked whatever the tribometer “saw.” Thus, if the tribometer's design made it incapable of seeing the correct frictional mechanism vis à vis pedestrian-generated friction, the force plate saw the same incorrect model. This paper summarizes the procedures used and continues the analysis of the workshop data, aggregating it by test condition.