A. Burkert et al., NOISE DIAGNOSTICS AT CORROSION PROCESSES PART 1 - EVALUATION OF A ROUND-ROBIN TEST, Werkstoffe und Korrosion, 49(9), 1998, pp. 630-641
The Institute of Materials Engineering and Materials Testing of the Un
iversity of Magdeburg (IWW) organised a round robin test on the measur
ement of electrochemical noise (EN) and obtained the participation of
17 organisations (universities, commercial firms, R&D laboratories) fr
om 5 countries. The experiment involved the investigation of EN signal
s from aluminium and stainless steel exposed under conditions in which
pitting corrosion can occur. The data provided by the participants we
re analysed at IWW according to various criteria. Evaluation methods i
ncluded visual inspection of the noise in the potential or current ver
sus time curves, calculation of the standard deviation, counting of tr
ansients and transformation of the measurements into the frequency dom
ain. Almost all of the participants were able to detect differences in
EN behaviour during different stages of the experiment qualitatively.
Quantitative evaluation, however, revealed a more complex situation.
At times, differences in measured EN signal intensity of two orders of
magnitude were obtained as a result of different apparatus used (sens
itivity, frequency range, etc.). Nevertheless, the fact that more than
half of the participants reported data within a relatively narrow sca
tterband is a positive result. The experience gained from the round ro
bin test provides a basis for further development of EN as a tool both
for the fundamental understanding of various aspects of corrosion and
for the solution of practical problems of corrosion protection, in pa
rticular in the area of corrosion monitoring.