TEST FREQUENCIES SELECTION CRITERIA FOR PARAMETER IDENTIFICATION OF ANTICORROSION COATING USING BILINEAR TRANSFORMATION

Marek Niedostatkiewicz, Grzegorz Lentka

Abstract

The electrical modelling of technical and biological objects has become very popular, as it allows diagnosis of their state with tools and methods designed for electrical circuits. To identify equivalent circuit parameters, usually conventional impedance spectroscopy methods are used, despite their drawbacks – long measurement time and high numerical complexity. An alternative identification method is based on the bilinear transformation of impedance function. Not only it accelerates the measurement, but also it simplifies the calculations, as the relations between measured impedance and parameters are analytical. However, the method requires a precise selection of impedance measurement frequencies. In the paper, we briefly present the bilinear identification method and compare some new frequencies selection criteria based on the length of bilinear transform identification curve on complex plane, representing the high-signal sensitivity of impedance function to model parameters. The criteria are compared in terms of identification error of parameters. As a test object the Beaunier’s model of the anticorrosion coating in its early stage of degradation has been chosen.

Download

IMEKO-TC4-2008-202.pdf

DOI

-

IMEKO TC

TC4 - Measurement of Electrical Quantities

Back to the proceedings