ASTM F3539-24

5.1 The test procedures and interlaboratory study report that result from coordinator compliance with this Practice are intended to include all information required for an ASTM Test Method and its associated Research Report; the interlaboratory study is to be conducted in compliance with Practice E691, also as required for an ASTM Test Method.3 The reason that the content of this Practice is not prepared as an actual ASTM Test Method is as follows. ASTM regulations preclude reference (in a Standard) to patented or otherwise proprietary test apparatus where “alternatives exist”.4 While a proprietary apparatus may be mentioned in the Test Method’s Research Report, this would prevent the Test Method from being a standalone document containing all information necessary for testing. As such, a standalone Test Method could only be for a non-proprietary apparatus design, with this design expressed in terms of physical characteristics and performance specifications sufficient to enable the reader to fabricate their own “identical” copy of the design. Further, to achieve consensus approval and publication of such a Test Method, it could be considered necessary that ILS results for this design include data from devices made by different entities. However, typical walkway tribometer designs (versus other types of test apparatus) are sufficiently complex that full documentation of all performance-affecting physical characteristics (sufficient that a reader could build one) may be impractical. European standard EN 16165 Annexes C and D illustrate what physical and performance characteristics are and are not documented in that standard’s specifications for two non-proprietary tribometers. In general, each different tribometer design may have advantages and disadvantages for testing different surfaces, and this Practice provides a rigorous and standardized structure for creating tribometer test procedures and interlaboratory study reports that would comply with the requirements for ASTM Test Methods, were it practical to create such test methods. It is recognized that a coordinator’s claim of compliance with this practice should be evaluated by the user, as formal consensus approval of the coordinator’s outputs will not have occurred.

5.2 If compliance with this practice is claimed by a coordinator, all steps in Section 6 shall have been followed.

5.3 The user can benefit from ILS reports and test procedures prepared in compliance with this standard, as there are potentially ~150 different elements (in Annex A1) of apparatus and methodological specifics, and it is important to note that the burden for specifying this information rests with the coordinator, not the user. The information will be there for the user if they want it.

5.4 Precision statistics obtained in an ILS conducted on a single sample of a particular reference material will not capture the frictional variability that exists between different samples of that same reference material. The ILS test procedure may not capture the frictional variability that exists within a single sample of that reference material. The ILS test procedure will not evaluate the stability of the frictional characteristics of a reference material with repeated use over time. While outside the scope of this practice, the homogeneity and stability of reference materials are relevant to the interpretation and utilization of ILS results. Refer to ISO Guide 35 for a discussion of these topics.

5.5 Friction measurements represent characteristics of a surface at the time of testing; the available friction of the surface after use may change significantly. As with reference materials, the measured friction of one sample of a manufactured walkway surface may not represent the friction of other samples of the same product.

5.6 Obtaining test results is one part of a multi-part process of determining whether the available friction of an underfoot surface is adequate. Appendix X1 outlines a set of standards the F13.10 subcommittee intends to develop towards this goal.