Ergodic Analysis of Three-Dimensional Chebyshev Spectrum of Electrochemical Noise

The ergodicity of electrochemical noise of corrosion process with respect to the three-dimensional Chebyshev spectrum is studied. The electrochemical noise of “two identical electrodes of steel St-3 in the NaCl + benzotriazole solution” corrosion system is measured. The use of the Chebyshev noise spectra in the test for the ergodicity of electrochemical noise is dictated by the fact that the intensity of the second and higher Chebyshev spectral lines is resistant to the trend of electrochemical noise. It is found that in the initial period of interaction between the electrode and electrolyte, the electrochemical noise of the corrosion process is characterized by a weak ergodicity. However, even in 2.5 h, the ergodicity test shows that the steady state is reached. A similar situation is observed for the electronic noise of measuring equipment. The test for the ergodicity of electronic noise using the second component of three-dimensional Chebyshev spectrum shows that the steady state is reached in 30 min after switching on the measuring equipment. The ergodicity test with respect to the second component of three-dimensional Chebyshev spectrum can be used for the analysis of ergodic properties of random noise of any nature even under the conditions of strong trend.