【国外标准】 Standard Practice for Calibration of the James Static Coefficient of Friction Machine

5.1 This practice is used to calibrate the James Machine for determination of static coefficient of friction of polish surfaces in accordance with Test Method D2047. Over considerable time and repeated use the James Machine may tend to mechanical misalignment, giving self-evident, anomalous readings. The periodic accumulation and comparison of data generated by this practice provides an indication of when the machine is no longer within the calibration limits and can no longer be expected to provide accurate and reliable data.5.2 Semi-automated James machines may perform an internal calibration/alignment test. These automated tests should be routinely run per the manufacturer's recommendation. If the repeatability tests of this practice indicate that the machine is out of calibration, the manufacturer should be contacted and their suggestions followed. Unqualified disassembly, modification, or adjustment may void the instrument warranty of semi-automated James Machines.1.1 This practice covers the testing of the James Machine for repeatability of static coefficient of friction, relative to a standard reference interface consisting of the working surfaces of Borco2 board and standard leather shoe sole material, or a control polish film and standard leather shoe material. The practice provides basis data on the stability of the James Machine to ensure accurate static coefficient of friction determinations over time and repeated use and for determining if the James Machine is mechanically calibrated and properly aligned.1.2 This practice is written specifically for James Machines with manual or motorized test table transport. Variations of this practice for the calibration of versions of James Machines which are semi-automated are obvious. Calibration practices suggested by the manufacturer of semi-automatic James Machines should be followed in preference to this practice.1.3 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.1.4 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.