a portable apparatus for testing the slip resistance of surfaces such as floors and bathtub surfaces operates by applying a load instantaneously to a pad of friction material resting on the surface at a selected angle of attack . an articulated linkage carrying the pad is set at a predetermined angle and the load is substantially instantaneously applied to determine whether the pad slips at the preset angle . tests may be successivley conducted at different angles of the linkage or a single go , no - go test may be conducted at a datum angle . the articulated linkage is carried on a pivoted frame which moves across a segment plate to establish the predetermined angle . a pawl and tooth type latching system holds the frame relative to the plate at the preset angle .