This article shows the results obtained in the application of State Estimation to a case of fault detection and diagnosis in an osmotic dehydration process. The disturbances that affect the measurements on the system are unknown but it is known that they are bounded. The tools used for the development of this work were the EMV (Extended Mean Value) and SIVIA (Set Inversion Via Interval Analysis) algorithms, which allow obtaining the necessary boundaries for the fault detection and diagnosis algorithm. The paper presents simulations and validations.