The use of a non-linear dynamic system such as the chaotic oscillator is presented in the methodology of measurement systems that involve passive sensors in their process, to help in the identication of the minimum variations that may occur in the measurement, of hence, in some cases it is not possible to classify the measurements obtained. This type of chaotic oscillator is sensitive to changes in its initial conditions, therefore, dierent types of chaotic attractors can be produced. Subsequently, the use of two methodologies for the identication of these variations in chaotic attractors is proposed, which are: the phase space dierence method and the method for estimating the dominant exponent of Lyapunov in attractors, to classify samples obtained in a more obvious way. In this research it was proved that implementing a passive sensor in a non-linear - chaotic system by setting initial conditions, specic measurement parameters and using the phase space dierentiation method to determine the minimum variations that occurred in the attractors, a Minimum variation in the response of the passive sensor of at least one ohm, allowing good progress in the implementation of this methodology in the measurement systems of passive sensors.