摘要 |
The invention provides a method of diagnosing a lubricated portion which can precisely measure a metal concentration in a lubricating oil and can diagnose accurately a state of the lubricated portion on the basis of a value of measurement. In accordance with the present diagnosing method, a lubricating oil picked up from the lubricated portion is diluted by an organic solvent so as to prepare a sample oil, the sample oil is filtrated by a filter so as to separate a large-diameter metal particle having a particle diameter larger than 0.5 mu m, a metal concentration of a solution formed by dissolving the large-diameter metal particle by an acid and a metal concentration of a filtrate including a small-diameter metal particle having a particle diameter equal to or smaller than 0.5 mu m is measured in accordance with the inductively coupled plasma analysis, an wear depth in the lubricated portion is determined on the basis of the respective metal concentrations of the solution and the filtrate, and an wear state of the lubricated portion is diagnosed on the basis of a rate of change of the wear depth in accordance with a time elapse. <IMAGE> |