This part of IS0 7176 specifies a test method for determining the coefficient of friction of a test surface that has a rough texture, such as unfinished concrete. In the event that the test method is used for smooth or polished surfaces, care should be exercised that the coefficient of friction is measured as being constant over the whole area of the test surface. Several test procedures for wheelchairs, e.g. those specified in IS0 7176-1, IS0 71762, IS0 7176-3, IS0 7176-6 and IS0 7176-10, require that the coefficient of friction of the test surface be within specified limits.