The authors are involved in realizing an innovative measurement instrument for the real-time estimation of Resistance (R), Inductance (L) and Capacitance (C) parameters that models real electrical passive components in non sinusoidal environment. This instrument aims to cover the lack of reference instruments and measurement methods for the assessment of electrical passive components in non sinusoidal conditions. In previous papers the authors proposed a measured method implemented in a FPGA platform. In this paper a further step is proposed optimizing the dynamic behavior of the instrument with respect to fast time-variant passive components. The novelty manly consists on the improved signal processing procedure that implements a “forgetting factor” to promptly respond to changes on monitored devices. A full characterization aiming in find a forgetting factor value able to find the best compromise between accuracy and response time together with tests executed on real signals were also reported.