Autoplay
Autocomplete
Previous Lesson
Complete and Continue
4. Measure Corrosion by Electrochemical Impedance Spectroscopy
Basics of Corrosion and Impedance in Electrochemical Systems
Introduction to Section 1 (2:09)
What is Electrochemical Impedance Spectroscopy? (4:31)
Understanding the Corroding Surface (9:33)
Resistive response of a simple corroding surface and Stern-Geary equation (5:23)
Double layer capacitance (3:21)
Electrolyte resistance (3:43)
Alternating current (AC) signals (2:29)
Understanding the concept of impedance (8:23)
Connecting impedances in series and in parallel (7:13)
Summary of Section 1 (2:52)
Section 1 Quiz
Surface processes and EIS responses
Introduction to Section 2 (2:05)
Measuring the EIS spectrum (10:03)
Interactive App: Simulate EIS signal (0:36)
Effects of polarisation resistance, electrolyte resistance and double layer capacitance (6:06)
Interactive App: Simulate EIS spectrum (0:26)
Interactive App: Simulate EIS spectrum (multi-curve) (0:25)
Impact of frequency range on resolvable parameters (5:49)
Impact of surface layers on EIS response (14:14)
Interactive App: Effect of parameters on EIS for surface with layer (0:55)
Effect of area and relative area on EIS spectra (11:57)
EIS response of a surface supporting a coating with defects (8:09)
Interactive App: Effect of relative area of regions with different behaviour. (0:46)
Interactive App: Effect of relative area of regions (multi curve) (0:24)
Summary of Section 2 (1:22)
Practical considerations for the measurement of EIS spectra
Introduction to Section 3 (1:56)
Measuring EIS at the corrosion potential (4:13)
Influence of signal amplitude on the EIS measurement (11:40)
Interactive App: Current response near corrosion potential (0:23)
Impact of measurement frequency range on measurement time (12:40)
Interactive App: Impact of parameters on measurement time (0:26)
Charge passed during EIS measurements (6:22)
Interactive App: Thickness of oxidised material (0:42)
Requirement of stationarity and noise-related issues (9:18)
S3 Summary (1:51)
Interpreting EIS spectra using equivalent circuit models and fitting
Introduction to Section 4 (2:04)
How fitting works (12:56)
Interactive App: Fitting process and error surface
Characteristic responses of individual equivalent circuit components (8:45)
Interactive App: Individual components impedance (0:28)
Key features in EIS spectra (13:44)
Interactive App: Response of circuit containing a CPE
Interactive App: Response of circuit containing CPE and Warburg short. (0:22)
Constructing an equivalent circuit model (16:28)
Practical example of fitting EIS data (16:36)
Interactive App: Fitting Example
Summary of Section 4 (1:57)
Teach online with
Double layer capacitance
Complete and Continue