Hi, I run the OCP corrosion test with the help of corrosion cell keeping Saturate calomel electrode as reference electrode, Stainless steel as working electrode and graphite as the counter electrode. The OCP lines was showing zig zag lines in smaller extent initially. But after I repeated the OCP more times the OCP started showing zig zag irregular lines in greater extent. I tried my best to troubleshoot it but could not do it. Can someone help me with this?
Pics : The irregular zig zag lines in the initial stages and after running multiples times.
Hi
It may be more than one reason first, electrode contamination: The electrodes may have been contaminated during the experiment, which could lead to erratic readings. In addition, we can refer to electrode polarization: Polarization of the working electrode or counter electrode can also cause irregular OCP lines.
Another reason is that when the reference electrode is not connected correctly or has a faulty junction, it can cause irregular OCP lines. In addition, we must be sure that solution does not contain impurities or contaminants, it can interfere with the OCP measurement and cause irregular readings. Make sure the solution is properly prepared and free from any impurities.
Some other parameters you have to examine like temperature variation cause temperature fluctuations that can also affect the OCP readings, leading to erratic lines and Electrode degradation, The electrodes may have degraded over time, leading to inconsistent readings. Consider replacing the electrodes if they have been used for a long time or show signs of wear and tear.
best regards
raghd
Raghd Muhi Al-Deen Jassim Sir thanks a lot for your reply. I checked it with pautolab and then it was coming without irregular lines. I tried checking with dummy cell to ensure if there is some problem with machine or cable and found that there is no problem with the same. I checked the reference electrode to ensure if it is working properly. The reference electrode is working properly.
Hi Sajna, this is a phenomenon called aliasing. The cause is the coupling of harmonic oscillations (from the power supply) due to a too high impedance in the reference electrode circuit. Here you must either filter better (low pass), lower the electrode impedance (measure beforehand, then e.g. check the salt bridge and the diaphragm for air bubbles or dried salt) or sample faster and then smooth the data. If the impedance and thus the interference is too high, it can overdrive the measuring amplifier and then you usually measure total nonsense (also in the DC range). Best regards, Andreas
Irregular lines observed in a corrosion cell experiment with stainless steel as the working electrode could be indicative of various factors that might be affecting the experiment. Corrosion experiments can be influenced by a range of variables, and pinpointing the exact cause of irregular lines requires careful consideration. Here are some possible errors and factors to consider:
To address these potential errors, carefully review your experimental procedures, ensure proper equipment calibration, and validate your experimental setup. If the irregular lines persist, consider seeking guidance from corrosion experts or colleagues experienced in electrochemical studies.
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