How to run Linear Polarization Resistance (LPR) for corrosion measurement using Metrohm DropSens

[@farhansobri6314]

Assalamualaikum Dr., thank you for the demonstration. Would appreciate it if you could also demonstrate a LPR analysis for microbial fuel cells too at some point :) looking forward to more videos from you 👍

[@mohdhazwan6523]

InsyaAllah in the next video

[@maskedpapa9895]

Hello Dr., I am a big fan of your electrochemical measuring technique video, and they have been truly informative. Could I please seek clarification regarding the terms below and their importance? I understand this is a lengthy comment, but your insights would be amazing. I am confused about the purpose of Open Circuit Potential, Linear Polarization, Potentiostatic Polarization, Potentiodynamic Polarization, Linear Polarization Resistance, and Cyclic Polarization. I realize this is quite a bit to ask, but I would genuinely appreciate your help in understanding these concepts.

[@mohdhazwan6523]

Hello, thank you for your comment. OCP: a transient measurement to see the changes between potential to time. We need to perform OCP beforehand because to know the steady state potential value to be polarized. LPR: polarization methods that use short potential range (+- 20 mV from OCP). The linear plot will be potential vs current and the gradient will give Rp value. icorr can be obtained from Rp through formula. PDP: polarization methods that use slightly bigger potential range (+- 250 mV). The resulted Tafel plot is current density vs potential and the icorr can be obtained from the intersection of the two linear anodic and cathodic tangent line. Corrosion rate can be obtained from icorr. Cyclic polarization: polarization methods that use longer anodic potential range (+1000 mV) mostly to study passivation, transpassive and pitting corrosion. The Tafel plot is similar with PDP technique but with addition of reverse cycle. This will give Epit, Erp and hysterisis information More infor can be check from my lectures in the channel

[@aliaatiqah4829]

Assalamualaikum w.b.t Dr, thank you so much for this video, I would like to ask you Dr, if we are analyzing two different compound as corrosion inhibitor (eg: A&B) is that possible they will give different outcome, for example in EIS, A shows better performance than B, but in Polarization, B gives better performance. I'm just wondering if that possible because different corrosion testing can highlight different aspects of a material's corrosion behaviour.

[@mohdhazwan6523]

Waalaikumsalam Alia. That might happened if the OCP has not been done long enough for both EIS or PDP analysis. Probably you should look at the total time used for OCP (open circuit potential?

[@aliaatiqah4829]

@@mohdhazwan6523 Thank you so much Dr for the suggestion, will try to figure it out soon, thank you Dr for always share your knowledge with us😁