ASTM G194-08 (R2018) pdf free download.Standard Test Method for Measuring Rolling Friction Characteristics of a Spherical Shape on a Flat Horizontal Plane.
1.1 This test method covers the use of an angled launch ramp to initiate rolling of a sphere or nearly spherical shape on a flat horizontal surface to determine the rolling friction characteristics of a given spherical shape on a given surface.
1.1.1 Steel balls on a surface plate were used in inrlahor 4itory tests (see Appendix X I). Golf halls on a green. soccer and lacrosse halls on playing surfaces, bowling halls on an a lane, basketballs on hardwood, and marbles on composite surface were tested in the development of this test method, hut the test applies to any sphere rolling on any flat hori,ontal surface.
1. 1.2 The rolling friction of spheres on horizontal surfaces is affected by the spherical shape’s stiffness, radius of curvature. surface texture, films on the surface, the nature of the counter- face surface: there are many factors to consider. This test method takes all of these factors into consideration. The spherical shape of interest is rolled on the surface of interest using a standard ramp to initiate rolling and standard techniques to measure and treat the rolled distance after leaving the ram P.
1. 1 .3 This lest method produces a rolling resistance number on a specific spherical shape on a specific surface. It is intended for comparing similar ribosystems. For example. the rolling resistances of marbles on a particular surface are not to be compared with the rolling resistance of soccer halls on grass, because their masses and diameters are very different as are the counterface surfaces on which they roll.
1.1 .4 Different launch ramps are appropriate for different types of spherical shapes. If a sphere of interest cannot be accommodated with using one of the launch ramps discussed in Appendix X I and Appendix X2, a different launch ramp can he developed and added with future revisions to this test method.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.ASTM G194 pdf download.