An article on reference cells published by my favorite reference cell supplier can be read here.
Another article published by my favorite permanent reference cell manufacturer can be read here and here too.
Another article published by my favorite permanent reference cell manufacturer can be read here and here too.
A half-cell is not used as a reference electrode during CIPS or traditional pipe-to-soil potential measurements otherwise DCVG would not be possible. The voltage between a half-cell and a standard reference electrode must be zero whereas we observe the voltage between two half-cells all the time during DCVG surveys. Which one is the reference against which we can measure the reaction potential as required by the Pourbaix diagrams and on which all cathodic protection design and and monitoring rely? We use exactly the same half-cell in a CIPS survey and call it a reference electrode?????
ReplyDeleteDCVG, CIPS, or traditional pipe-to-soil potential surveys are as far as I am concerned a testing method to find anodic areas and / or pipe coating damage. It has no direct relationship to the Pourbaix diagrams. As an method to find anodic areas along the pipeline or locations of coating damage; it has its usefulness and limitations.
ReplyDeleteHaving read the recommended paper again it is clear that it is correct in the same way that all other papers on this subject are correct. They all miss the point I have been making for the past 30 years or more and that is that when you take a reading between two identical 'reference electrodes' you should read zero on the voltmeter. In cathodic protection field work you do not. The demonstrations that I have published show photographs of repeatable experiments to prove this.
ReplyDeleteIn 1972 I found that the explanation for my work in the NACE reference book (Peabody's) did not render the same results as I was getting in the field.
My experiments proved that there is no way to apply the scientific logic of the reference cell concept in corrosion control field work as the voltage measurements must be made between the reference cell and the metal at the anodic interface of the subject metal and it's electrolyte.
The values shown in the diagrams, in the paper you recommend above, must be measured using laboratory techniques as any other method disturbs the very conditions that you are trying to measure. Each point of measurement is set up at the reaction interface whereas in field work the reference cell is placed in the common electrolyte of all the interfaces on the subject structure.
The free on-line cathodic protection course contains full explanations of this and includes experiments that can be carried out by the student using instruments and materials that are available world wide.
The reason for publishing all this stuff on the internet now is that I am now 71 years old and have travelled the world meeting highly qualified corrosion scientists and corrosion control engineers (including John Leeds) who have all recognised the truth of my assumptions. They have all recognised that the only way to monitor the effects of cathodic protection on the corrosion reaction is by some electrode system, as the priciples of the reference electrode as set out in the papers you recommend cannot be applied in the field.
This is a matter of fact that is repeatedy observable in the experiments that I have published.
As a result of my stubborn certainty and scientific integrity, I live alone and have no money. Cathodic Protection Network is not a commercial venture and we are not interested in sales. What you describe as 'marketing' is simply spreading intellectual property freely over the internet. I have earned money most of my life by stopping corrosion on pipelines where others have failed.