The present thesis project is the outcome of an extended experimental investigation on tribology within the framework of a joint research project between Politecnico di Torino (IT) and Anton Paar TriTec SA (CH). It deals with the revision of the most commonly used standard for the pin-on-disk tribometers: ASTM G99. The aim is to develop one new procedure for coatings and one reference procedure for the diagnostics on pin-on-disk tribometers. As this paper covers two separate issues within the subject of tribology, it has two distinct sections. In Part I, the experimental results from several tests carried out with a particular elastohydrodynamic lubricated condition free of oil bath are presented and discussed.