This paper deals with the Fault Detection and Isolation (FDI) on industrial systems such as steam generator process whose model is non linear. The method is based on Analytical Redundancy Relations which are generated from a bipartite graph These relations are used to detect and isolate Sensor Fault using structural analysis, based on the elimination of the unmeasured variables of the system. Simulations are used to detect and isolate multiple sensor faults in order to prove the efficiency of our method