Method and apparatus for monitoring a fluid carrying system

A method for monitoring a fluid-carrying system, in particular a hydraulic system, comprising the determination of the presence of particles in the fluid and / or determining the degree of contamination by at least one means for detecting individual particles such as a particle counter, is characterized in that a predetermined time period of time for each time increment (X) the number of particles and / or the degree of contamination determines the resultant from the particle number and / or the degree of contamination count increment (Isae) summed over the predetermined period of time and if a predetermined limit value (WCL) and / or at the expiration of the predetermined time period of service requirement is issued.