1、Designation: F2508 12aF2508 13 An American National StandardStandard Practice forValidation, Calibration, and Certification of WalkwayTribometers Using Reference Surfaces1This standard is issued under the fixed designation F2508; the number immediately following the designation indicates the year of
2、original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice is intended to establish the procedures for v
3、alidation, calibration, and certification of walkway tribometers.1.2 This practice provides a walkway tribometer supplier with a procedure and suite of reference surfaces to validate hiswalkway tribometer by properly ranking and differentiating the surfaces.1.3 This practice provides the user of a w
4、alkway tribometer with a procedure and suite of reference surfaces to test calibrationof his instrument.1.4 This practice provides a procedure through which an entity may certify a walkway tribometer model, signifying that thewalkway tribometer model has a completed and documented validation and int
5、erlaboratory study.1.5 This practice describes the necessary materials, specifications, and the cleaning process for reference materials, as well asthe requirements for the validation of a suppliers walkway tribometer and calibration of a users walkway tribometer.1.6 This practice applies to walkway
6、 tribometers without reference to the nature of the scale of the readings produced by them.The scale used in the reports of validation and calibration must be the same, and are to be those of the instrument or defined forthe instrument.1.7 The values stated in SI units are to be regarded as standard
7、. The values given in parentheses are for information only andare not considered standard.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practic
8、es and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Temperatures for TestingD3244 Practice for Utilization of Test Data to Determine Conformance with SpecificationsE691 Practice for Conducting an Interl
9、aboratory Study to Determine the Precision of a Test MethodF1646 Terminology Relating to Safety and Traction for Footwear3. Terminology3.1 For terms used in this practice not identified herein, refer to Terminology F1646.3.2 Definitions:3.1.1 For terms used in this practice not identified herein, re
10、fer to Terminology F1646.3.2.1 paired t-test, na test of statistical significance based on the use of students t-distribution and used to compare twosample means (see Appendix X2).3.2.2 supplier, nany individual, agent, company, manufacturer, or organization responsible for the walkway tribometer pr
11、iorto receipt by the user. D32441 This practice is under the jurisdiction of ASTM Committee F13 on Pedestrian/Walkway Safety and Footwear and is the direct responsibility of Subcommittee F13.10on Traction.Current edition approved Nov. 1, 2012April 1, 2013. Published December 2012April 2013. Original
12、ly approved in 2011. Last previous edition approved in 2012 as F2508 12.12a. DOI: 10.1520/F2508-12A.10.1520/F2508-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to
13、the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes
14、accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United
15、 States13.2.3 test foot, nshoe bottom material or surrogate mounted on the walkway tribometer that comes into contact with thesurface being tested.3.2.4 walkway tribometer, nany apparatus used to measure the frictional forces acting at an interface between a walkwaysurface and shoe material.3.2.4.1
16、DiscussionA judgement of the adequacy of these frictional forces acting on a walkway surface/shoe surface interface is the basis for anassessment of slip properties relative to human locomotion.3.3 Definitions of Terms Specific to This Standard:3.3.1 calibration, nthe set of operations that establis
17、hes, under specified conditions, the relationship between the valuesobtained by a walkway tribometer and the corresponding supplier reference values.3.3.2 certification test method, na specific test method that is used for all walkway tribometer operational tasks in this practiceperformed as part of
18、 a certification.3.3.3 laboratory, na combination of one individual, uniquely identifiable walkway tribometer, one individual, uniquelyidentifiable test foot, and one operator, none of which (or whom) may be reused for the same purpose in the interlaboratory studybeing conducted.3.3.4 reference surf
19、aces (RSs), nspecified materials, identified in Section 7, that have an experimentally demonstrated slipproperties for a select population of pedestrians and serve as references for walkway tribometer measurements.3.3.5 validation, nthe set of operations that establishes, under specified conditions,
20、 the proper ranking and differentiation ofreference surfaces by a walkway tribometer.4. Summary of Practice4.1 This practice establishes a procedure to: (1) validate walkway tribometer models against a human gait-based referencesystem, (2) calibrate each individual walkway tribometers of a validated
21、 model against published suppliers reference values (asdefined in 9.1, Eq 4), and (3) certify that the tribometer model has completed a documented validation and interlaboratory study.4.2 This practice provides for validation and calibration of walkway tribometers as a means of verifying their relat
22、ionship toreference surfaces and verifying a particular device continues to produce consistent results. Certification, if conducted, formallydocuments the methods, data, and results of a validation and interlaboratory study.4.3 The method of ranking walkway surface slip properties using a limited po
23、pulation of ambulating human subjects issupported by a peer-reviewed study.34.4 Validation consists of a series of 40 tests on each reference surface from this practice. A walkway tribometer model isconsidered valid if it ranks the four reference surfaces from this practice in the proper order with
24、statistically significantdifferentiation between results obtained for each surface. Validation is intended to be accomplished for each walkway tribometermodel when it is initially introduced and is to be accomplished by or on behalf of the supplier and made available to each user.4.5 Calibration for
25、 a specific walkway tribometer requires a series of 16 tests on each of the reference surfaces from thispractice. A specific walkway tribometer is considered within calibration if the bias of the mean test values for each surface fallswithin the 95 % confidence interval for the walkway tribometer mo
26、del as established by the validation tests (as defined in 9.1, Eq4).5. Significance and Use5.1 To be meaningful, walkway tribometer results must correlate the slip characteristics of a surface or contaminant, or both,to the actual propensity for human slips. To achieve this goal, walkway tribometer
27、models must be validated against a standardwith relevance to human ambulation.5.2 This practice prescribes a series of reference surfaces with known relative slip potential ranging from very high to low (asdefined by laboratory conditions only) upon which walkway tribometer models can be validated.
28、The relative slip potential of eachreference surface was established from human subject walking trials.35.3 The following should be considered in applying the validation and calibration obtained by this practice:5.3.1 The scientific study upon which the validation process is based was conducted with
29、 a select population of young adults(mean age 26 years) who were free from gait deviations while walking in a straight path on a level surface with a mean walkingvelocity of 2.18 m/s. This walking velocity is faster than the average walking velocity for the general population which includes3 Powers,
30、 C. M., Blanchette, M. G., Brault, J. R., Flynn, J., and Siegmund, G. P., “Validation of Walkway Tribometers: Establishing a Reference Standard,” Journal ofForensic Sciences, Vol. 55, No. 2, March 2010, pp. 366370.F2508 132a much wider age range with greater variability; thus, the study sample popul
31、ation of pedestrians and conditions is notrepresentative of the larger general population of pedestrians.5.3.2 All subjects walked in Oxford-style shoes whose soles were constructed of smooth styrene butadiene rubber (SBR) with75A Shore hardness. The shoe style and sole material is not representativ
32、e of all combinations available in the marketplace.5.3.3 The reference surfaces defined in this practice are not representative of all walkway surfaces. The outcome of thevalidation practice reflects performance on the type of reference surfaces and surface conditions defined in this practice only.V
33、alidation and calibration of a walkway tribometer as defined by this practice does not imply validation and calibration under allcombinations of test foot materials and walkway surfaces.5.3.4 The validation and calibration procedure defined by this practice is not intended to establish a “safe thres
34、hold” value forany walkway surface.6. Apparatus6.1 The walkway tribometer shall be free of defects and operational throughout its range. Refer to the walkway tribometerinstruction manual to ensure proper operation and instrument condition before the validation and calibration process.6.2 Test Foot D
35、esignation and Condition:6.2.1 The supplier must provide test foot material, dimension, storage, and service life specifications. The specifications shallbe sufficient to permit procurement of an exemplar test foot.6.2.2 A uniquely numbered test foot, meeting the suppliers material and dimensional s
36、pecifications shall be provided with thewalkway tribometer being tested.6.2.2.1 The calibration results shall apply only to the walkway tribometer/test foot combination tested.6.2.3 Prepare the test foot as prescribed by the walkway tribometer supplier or by a fully documented procedure included int
37、he validation or calibration report.7. Reference Surfaces (RSs)47.1 Reference Surfaces:7.1.1 RS APolished black granite whose surface beneath the test foot is covered with a continuous film of 0.04 % by volumesolution of Triton X-1005 (nonionic surfactant) in distilled water (that is, 200 L of Trito
38、n X-100 per 500 mL of distilled water).7.1.2 RS BPorcelain whose surface beneath the test foot is covered with a continuous film of distilled water.7.1.3 RS CVinyl composition tile whose surface beneath the test foot is covered with a continuous film of distilled water.7.1.4 RS DCeramic whose surfac
39、e beneath the test foot is covered with a continuous film of distilled water.7.2 Each RS shall be permanently marked to designate its reference class (that is, “A”, “B”, “C”, “D”).7.3 Reference surfaces shall be stored in a manner that prevents deformation and contamination.7.4 Reference surfaces sh
40、ould not be used for validation or calibration testing after 5 years from date of purchase.8. Procedure8.1 EnvironmentThe validation and calibration test shall be performed at a humidity level of 50 6 5 % and a temperaturerange of 23 6 2C (73.4 6 3.6F) (derived from Practice D1349).8.2 Reference Sur
41、face PreparationThe reference surface shall be free from visible dents, cracks, voids, or other significantblemishes.8.2.1 Cleaning:8.2.1.1 No surface treatment except as specified in this section is permitted.8.2.1.2 Prepare a 0.05 % by volume solution of liquid sodium lauryl sulfate in distilled w
42、ater (that is, 250 L of sodium laurylsulfate per 500 mL of distilled water).8.2.1.3 Dip a clean soft-bristled nylon brush in the cleaning solution and gently scrub in a circular pattern the entire referencesurface for a minimum of 10 s. Reapply the cleaning solution and repeat the minimum 10-s scrub
43、bing two times.8.2.1.4 Rinse the surface thoroughly with distilled water, ensuring that no visible suds or soap residues remain.8.2.1.5 Dry the surface with dry and oil-free compressed air or air dry if compressed air is not available. The reference surfaceshall exhibit no visible moisture film or d
44、roplets.8.2.1.6 Prepare an ethanol solution containing equal parts denatured ethanol in distilled water.8.2.1.7 Dip a clean soft-bristled nylon brush, different from that used in 8.2.1.3, in the ethanol solution and gently scrub thereference surface for 10 s.4 Available from ASTM International Headq
45、uarters. Order Adjunct No. ADJF2508. Original adjunct produced in 2011.5 The sole source of supply of the apparatus known to the committee at this time is Gallade Chemical, Santa Ana, CA. If you are aware of alternative suppliers, pleaseprovide this information to ASTM International Headquarters. Yo
46、ur comments will receive careful consideration at a meeting of the responsible technical committee,1 whichyou may attend.F2508 1338.2.1.8 Dry the reference surface with dry and oil-free compressed air or air dry if compressed air is not available. Any visiblecontamination remaining after this step w
47、ill disqualify the reference surface for use.8.2.1.9 Ensure that handling of the reference surface does not introduce contaminants to the surfaces, including exposing thesurfaces to contact of human skin.8.2.1.10 The cleaning procedure should be performed before each testing session.8.3 Reference Su
48、rface MountingMount the reference surface onto a flat and rigid substrate that prevents movement of thereference surface parallel to the test plane of the walkway tribometer during testing. Select a substrate that will not deform duringwet testing.8.4 Walkway Tribometer Validation TestingUsing the w
49、alkway tribometer being validated and the test foot prepared in 6.2.3,perform 40 tests in accordance with a uniquely identifiable version of the walkway tribometer suppliers operating instructions orany other formal procedure in the test area of each of the four reference surfaces that have been prepared in accordance with 8.2.Of the 40 tests, perform 10 in each of 4 orthogonal directions, that is, at 0, 90, 180, and 270 relative to an arbitrarily defineddirection on the reference surface. Record the results of all tests as specified in Section 10
