STP1188: Validation of Experimental Data from High Impedance Systems Using the Kramers-Kronig Transforms

    Dougherty, BJ
    SRI International, Menlo Park, CA

    Smedley, SI
    SRI International, Menlo Park, CA

    Pages: 17    Published: Jan 1993


    Abstract

    Impedance data measured for the high impedance aluminum/methanol and aluminum/methanol/water systems have been validated using the Kramers-Kronig Transforms (KKT). The real-to-imaginary and imaginary-to-real transforms gave accurate results for experimental data which met the linearity, causality, stability, and continuity and finiteness criteria. In cases in which only the continuity and finiteness criterion was violated, the magnitude of the real impedance calculated from the imaginary-to-real transform and the maximum value of the imaginary impedance calculated from the real-to-imaginary transform were smaller than the experimental values. The real-to-imaginary transform was more sensitive to errors of this type than the imaginary-to-real transform. Neither transform produced accurate results when the linearity, stability, and causality requirements were violated.

    Keywords:

    Kramers-Kronig Transforms (KKT), impedance, corrosion, aluminum, methanol, water


    Paper ID: STP18068S

    Committee/Subcommittee: G01.11

    DOI: 10.1520/STP18068S


    CrossRef ASTM International is a member of CrossRef.