< div class=" SectionLevel2" > < p class=" subsec1 cdone2" > < span class=" Head3 cdone" > 1.1< / span> & #x00a0 This test method describes the equipment and procedure to ensure that the calibration performed by various dynamic friction tester (DF tester) users is uniform and in accordance with manufacturer specifications. There are three models of the DF tester in use: (< span style=" font-style:italic font-weight:normal " class=" overriddenformat" > 1< / span> ) USB/ personal computer, (< span style=" font-style:italic font-weight:normal " class=" overriddenformat" > 2< / span> ) controller, and (< span style=" font-style:italic font-weight:normal " class=" overriddenformat" > 3< / span> ) X-Y plotter. Procedures specific to the different models are noted. User-level calibration software is separate from the operation software and must be obtained from the manufacturer for the USB/ personal computer model.

< / div> < div class=" SectionLevel2" > < p class=" subsec1 cdone2" > < span class=" Head3 cdone" > 1.2< / span> & #x00a0 This test method is a static calibration of the vertical load, friction (& #x00b5 ) force, and speed of the DF tester. Compliance to this user-level calibration procedure ensures a higher level of repeatable and reproducible performance of the DF tester when used in accordance with Test Method < span class=" Body-link1 cdone" > E1911< / span> .

< / div> < div class=" SectionLevel2" > < p class=" subsec1 cdone2" > < span class=" Head3 cdone" > 1.3< / span> & #x00a0 The user-level calibration doesn& #x2019 t include the replacement of the mu spring or the adjustment of linearity of the DF tester. It is recommended that DF testers be inspected by a manufacturer-approved laboratory on an annual basis to replace the mu spring, ensure linearity, and to identify other non user-serviceable wear.

< / div> < div class=" SectionLevel2" > < p class=" subsec1 cdone2" > < span class=" Head3 cdone" > 1.4< / span> & #x00a0 The values stated in SI (metric) units are to be regarded as standard. The inch-pound equivalents are rationalized, rather than exact mathematical conversions.

< / div> < div class=" SectionLevel2" > < p class=" caveat cdone2" > < span class=" Head3 cdone" > 1.5< / span> & #x00a0 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.

< / div> < div class=" SectionLevel2" > < p class=" WTOcaveat cdone2" > < span class=" Head3 cdone" > 1.6< / span> & #x00a0 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.

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