Apparatus for determining coefficients of friction

An apparatus for determining coefficients of friction, comprising:

• a flat, planar base;
• a ramp having a base attachment end and an elevating end opposite the base attachment end, the base attachment end being pivotally attached to the base;
• means for gradually and continuously raising the elevating end of the ramp;
• a digital angle meter having a display, the digital angle meter being mounted on the base and configured for measuring and displaying the angle between the base and the ramp;
• a plurality of test masses, the test masses each being of different materials and different masses from one another;
• a plurality of test surfaces, the test surfaces being selectively interchangeably disposed upon the ramp, wherein the plurality of test surfaces are selected from a group consisting of concrete, asphalt paving, and wood;
• a pair of timing sensors mounted on the ramp and separated by a measured distance, the timing sensors including a starting sensor mounted at the elevating end of the ramp and a finishing sensor mounted at the base attachment end of the ramp, the timing sensors having means for generating a start signal when one of the test masses slides past the starting sensor and means for generating a finish signal when one of the test masses slides past the finishing sensor;
• and
• a timing device connected to the timing sensors, the timing device having a display, the timing device having means for computing and displaying the elapsed time between the start signal and the finish signal.