Slip resistance is measured in several ways, and the results are not interchangeable. The method a project needs depends on the country and on the use of the floor.
Ramp tests
In the shod ramp test of DIN 51130, a person walks on an oiled, inclined surface; the angle at which they slip gives a class from R9 (6° to 10°) to R13 (above 35°). The barefoot test of DIN 51097 gives classes A, B and C for wet areas such as pool surrounds and showers. EN 16165 gathers the European test methods.