Corrosion monitoring with speckle correlation

The changes in the microtopography of a metal surface during a corrosion process are measured by decorrelation of the scattered speckle fields under coherent illumination. For that purpose a quantitative relation between the decorrelation of the scattered light fields and the rate of corrosion is es...

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Bibliographic Details
Published inApplied optics (2004) Vol. 38; no. 28; p. 5948
Main Authors Fricke-Begemann, T, Gülker, G, Hinsch, K D, Wolff, K
Format Journal Article
LanguageEnglish
Published United States 01.10.1999
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Summary:The changes in the microtopography of a metal surface during a corrosion process are measured by decorrelation of the scattered speckle fields under coherent illumination. For that purpose a quantitative relation between the decorrelation of the scattered light fields and the rate of corrosion is established in a theoretical model, based on the statistics of phase and reflectivity changes of point scatterers at the surface. The speckle fields are recorded by a CCD camera and processed numerically in a computer, yielding the standard deviation of the topography changes with nanometer sensitivity. From the analysis of a series of images taken at equal time intervals during the corrosion process, the degree of interrelation among subsequent topography changes is calculated.
ISSN:1559-128X
DOI:10.1364/AO.38.005948