Abstract：In tribology, friction coefficient and wear rate are usually determined experimentally The present work is aimed at investigating the measuring uncertainties associated with the evaluation of these two parameters In particular, a standard pinondisk tribometer, having two pins constrained to a counterface, has been used Varying normal load, sliding distance and test duration, a total of twenty tests have been carried out Environmental temperature and relative humidity have been maintained constant After the tests, a stylus profilometer has been used to acquire the wear scar profiles on the crosssections of the disks The wear rates have been subsequently calculated by measuring the area of the wear track crosssections and evaluating an average wear volume The experimental results show that the load measurement uncertainty strongly affects the evaluation of both friction coefficient and wear rate The information obtained are useful to optimise the experimental apparatus and/or to develop suitable procedures aimed at reducing measurement uncertainties.
［1］Cunningham J M, Garcia Marirrodriga C. A practical assessment of data repeatability & reproducibility in tribometer tests for space applications［C］. Proc Sixth European Space Mechanisms & Tribology Symposium, Technopark, Zurich, Switzerland，46，October 1995，3543.
［2］ Guicciardi S, Melandri C, Lucchini F, et al On data dispersion in pinondisk wear tests［J］. Wear，2002，252:10011006.
［3］ Almond E A. Gee M, Results from a UK interlaboratory project on dry sliding wear［J］. Wear，1987，120，101116.
［4］ Burris D L, Sawyer W G. Addressing practical challenges of low friction coefficient measurements［J］. Tribol Lett，2009，35:1723.
［5］ Schmitz T L, Action J E, Ziegert J C, et al The difficulty of measuring low friction: uncertainty analysis for friction coefficient measurements［J］. J Tribol，2005，127:673678.
［6］ Schmitz T L, Action J E, Ziegert J C, et al, Wearrate uncertainty analysis［J］. J Tribol Trans ASME，2004，126: 802808.
［7］ Ludema K C. Friction, wear, lubrication: a textbook in tribology［M］. CRC Press,1996.
［8］ Figliola R S, Beasley D E. Theory and design for mechanical measurements:4th edition ［M］.Wiley.
［9］ Burris D L, Sawyer W G. Measurement uncertainties in wear rates［J］. Tribol Lett, 2009, 36: 8187.
［10］ ASTM G 9905 Standard test method for wear testing with a pinondisk apparatus［S］.
［11］ISO/IEC Guide 98 A Guide to Expression of Uncertainty in Measurement［S］.
