This paper discusses the application of fractal geometry theory in ferrography monitoring technology like the identification of wear particles, the calculation of fractal dimension and so on.

The basic principles,methods of monitoring with iron spectrum and it′s position in monitoring the working conditions for mining machinery are illuminated in this paper.

The technology of on-line ferrograph is a sort of wear condition realtime monitoring technology which are developed from the analysis ferrograph.

Application and research of ferrography in judging the wear condition of engine;

Application of Ferrography and Comprehensive Diagnosis Technique;

The Application of Weibull Distribution in the Ferrography Based on Debris Group Theory;

Described the methods of ferrography technology and its application in device monitoring and failure diagnosis.

With the rapid development of the computer technology and artificial intelligence technology, some methods were applied in the ferrography technology, such as computer vision technology, expert system, artificial neural network and fuzzy theory.

We have researched and mornitored the fatigue failure process of rolling bearings by using ferrographic technology and SEM The research shows that the ferrographic technology is very useful for studying the wear mechanisms and the monitoring of the wear condition of rolling bearings.

the ferrographic technology, spectrometric technology and the measurement technology performance index of lubricating oil as tools of wear state monitoring, combined with the actual conditions of Kai Lin Group, the application reseaches are carried out to monitor the state of wear a.