5.1 To be meaningful, walkway tribometer test results must be linked to the performance of humans walking over specific walking surface conditions that vary in slip potential. Validation under this practice does not apply to an entire class or model of tribometers; it applies to an individual tribometer unit as operated by the person conducting the validation.

5.1.1 When the user performs the validation, it demonstrates that the tribometer/operator passes the three validation criteria under repeatability conditions. When the coordinator performs the validation, it demonstrates that the tribometer/operator passes the three validation criteria under reproducibility conditions. As the reproducibility limit for a particular RM may be greater than the repeatability limit, it may be more challenging for a tribometer to pass validation when attempted by the coordinator. Statistically, a coordinator-validated tribometer better accommodates multiple operators.

5.2 This practice prescribes a series of RMs with known relative slip potential ranging from high to low (as determined by human testing in laboratory conditions) upon which walkway tribometers shall be validated. The relative slip potential of each RM was established from human subject walking trials.5

5.3 The scientific study upon which the validation process is based was conducted with a select population of younger adults (mean age 25 years, range 21 to 40 years) who were free from significant gait deviations while walking in a straight path on a level surface with a mean walking velocity of 1.4 m/s ± 5 %. This walking velocity is reported as the normal walking velocity for adults without gait pathology.6

5.4 All subjects walked in Gibson-style shoes whose soles were constructed of smooth styrene butadiene rubber (SBR) with 75A Shore hardness. The shoe style and sole material is not representative of all combinations available in the marketplace.

5.5 The RMs defined in this practice (see Annex A1) are not representative of all walkway surfaces. The outcome of the validation practice reflects performance on the type of RMs and surface conditions defined in this practice only. The RMs utilized are from specific manufacturing lots of product made available exclusively through ASTM-controlled sourcing, which are not necessarily representative of other manufacturing lots of the same product. Information on the RMs is available in the study publication.5 Validation of a walkway tribometer as defined by this practice does not imply validation under all combinations of slider materials and walkway surfaces.

1.1 This practice establishes a procedure for validating walkway tribometry using reference materials that have been ranked and differentiated by human subjects in a peer-reviewed study.

1.2 This practice describes the necessary materials, specifications, and cleaning processes for reference materials.

1.3 This practice applies to walkway tribometers without reference to the nature of the scale of the readings produced by them.

1.4 The validation procedure defined by this practice is not intended to establish a “safe” threshold value for any walkway surface.

1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only and are not considered standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.