Talk:DCVG

Notability
I propose removing the notability template. DCVG is described in the NACE International Standard TM0109. There is a journal article on the topic, however, the journal article is from the 1980' sand not available freely on the internet. That does not mean the topic does not warrant an article. Cafe Nervosa (talk) 00:18, 18 August 2017 (UTC)

Untitled
You say the procedure was invented by John Mulvaney in the 1980's, but doesn't Peabody describe the use of two half cells to measure potential gradient earlier than that. Also I've seen a website written by Roger Alexander, where he claims to be doing it in the 70's. I'm thinking of editing the page to reflect this. I'd be interested in your thoughts first. Apau98 (talk) 18:44, 15 September 2008 (UTC)
 * Apau, Don't believe everything you read on the Internet. I have corresponded with Roger Alexander as we are both active on Linkedin.  I am a certified NACE CP expert and work full time in the industry.  IMO Mr. Alexander operates independently from the corrosion control industry's Professional Technical Associations (Namely NACE International) and Mr. Alexander believes the entire industry relies on faulty science in pipe-to-soil potential measurements.  He claims to produce "peer reviewed" papers but these are not published in known journals and his websites with the papers do not have discussion forums to facilitate scientific debate and scrutiny.  Cafe Nervosa (talk) 03:02, 21 December 2012 (UTC)


 * Cafe Nervosa, I certainly don't believe everything I read on the internet, and I don't claim to believe Rodger Alexander. By the same token, I wasn't prepared to accept the claim that the DCVG technique was invented by Mulvaney and Leeds, without some independent sources. Same goes for everything on Wikipedia. Rodger Alexander's work certainly isn't mainstream and as you say not open to scientific debate and scrutiny, however, his claim would have seemed to have had as much validity as anyone else's in the absence of any references. I see below that you mention an article in Materials Performance April (No. 4) 1989, which sounds interesting. If the original author had included this as a citation, I'm sure I wouldn't have made a comment. Apau98 (talk) 17:45, 2 March 2013 (UTC)


 * A.W. Peabody wrote a paper in 1962 in Materials Performance about survey techniques, however, in his 1967 book, he did not describe DCVG. Something like DCVG does appear in the second edition but that was published in 2001 so ... Cafe Nervosa (talk) 22:10, 2 June 2012 (UTC)

Could you please provide your references (presumably web pages ?) so that I can look into this. I work for Dr John Leeds at DCVG Ltd who fomulated the DCVG working practices for NACE International, so I assumed that his history was correct. Could be that we're talking about slightly different things here. Thanks. —Preceding unsigned comment added by Wiganwoking (talk • contribs) 10:37, 24 September 2008 (UTC)

Update 14:00 BST 24/09/2008: I have consulted Chapter 6 of Control of Pipeline Corrosion by A.W. Peabody, dated 1981. There is no mention of the DCVG technique, but there is a section on Potential Surveys which is sometimes mistaken for it. The DCVG method uses two reference cells to measure potential differences across the soil directly, the Potential Survey method relies on taking pipe to soil measurements, the calculated difference between two adjacent points being used to calculate potential gradients. THE TWO TECHNIQUES ARE NOT IDENTICAL. The DCVG Technique provides both a means of quantifying faults AND their accurate location.

Regarding claims for the "invention" or earlier use of DCVG techniques - there are many people claiming this, but we have measured data and survey results which show who really developed and popularised its use. I haven;t reviewed a copy but here is a citation that may apply Materials Performance April (No. 4) 1989 New Pipeline Coating Defect Surveying Equipment for Corrosion Protection Assessment, J. MulvanyCafe Nervosa (talk) 22:10, 2 June 2012 (UTC)

As soon as I have time, I will add references and links to clarify matters. By all means add to the article if you wish, but please do not help those who propogate spurious claims. Thanks —Preceding unsigned comment added by Wiganwoking (talk • contribs) 13:07, 24 September 2008 (UTC)

Please refer to Chapter 5 of Control of Pipeline Corrosion by A.W. Peabody, pages 76/77, which quite clearly shows the use of a matched pair of half cells to measure current flow on/off the pipeline by measuring the volt drop. Isn't that basically the same technique? I don't accept that potential gradient surveys are often confused with potential surveys - they are quite different.
 * You are referring to the second edition, published in 2001 and it does not describe the method to precisely locate a coating defect and characterize the severity, so I see nothing to indicate that Peabody is the originator. Cafe Nervosa (talk) 22:10, 2 June 2012 (UTC)

I have no doubt your company developed and popularised the technique, but this is not the same as inventing it.Apau98 (talk) 22:35, 6 October 2008 (UTC)

Update 11:00 BST 25/11/2008: I have again consulted Control of Pipeline Corrosion by A.W. Peabody, dated 1981. I cannot reconcile your chapter/page references with it (presumably we have different editions ?), but I have found a pipe-to-earth survey method in Chapter 7 (Instrumentation) pages 80 & 81. Again, this is not the same as the DCVG technique, even though it does use two electrodes for some of the measurements. This method is an alternative to the conventional pipe-to-earth technique, using measured soil to soil potentials together with an initial pipe-to-soil measurement to calculate pipe-to-soil potentials along the pipeline. Its sole benefit appears to be the absence of a trailing wire, with the major disadvantage of accumulating errors and measurement mistakes the further down the pipeline you travel. DCVG is a precisely defined method which is much more than simply using two electrodes to take measurements, the accurate coating fault location and severity quantification being the two main features. Hope this clarifys matters.


 * This article has been tagged as needing citations since 2006, and following the earlier discussion in 2008, there are still no sources for the article. Does anyone know of any independent, verifiable sources? I haven't been able to find any and the article remains unsourced. Would this be a case for nomination for deletion? The previous discussion involved an employee of DCVG Ltd, and the article creator (DcvgDesign) has only contributed to this article, which raises doubts about impartiality and NPOV, especially in the absence of sources. Apau98 (talk) 15:24, 25 December 2010 (UTC)


 * Rather than deletion, would it be more suitable for merging into the article on Cathodic protection in the 'Testing' section? Apau98 (talk) 09:41, 4 January 2011 (UTC)
 * It has been restored and may not be that nobale, but rather lke a candiate for merging into Cathodic protection. --Tikiwont (talk) 20:39, 8 October 2011 (UTC)
 * I vote that is NOT be merged into cathodic protection and NOT be deleted. DCVG is not CP.  Pipeline protection starts with the coating, then the CP. DCVG helps find coating problems using a test equipment similar to the test to verify adequate CP, but the test is distinctly different.  I have Peabody's 1967 edition.  In the 1967 edition of Peabody Chapter Six "Survey Methods and Techniques" describes ten survey techniques and  none of them are DCVG.  The tenth is the closest.  Measurement of Earth Currents at the surface using a probe with two reference electrodes inserted into the ground near a pipe to indicate if current is flowing to or from the pipe.Cafe Nervosa (talk) 21:16, 2 June 2012 (UTC)
 * In retrospect, I think I agree. DCVG is a coating test not a CP test Apau98 (talk) 17:45, 2 March 2013 (UTC)

I looked through Peabody's 2nd edition (year 2001 ISBN 1-57590-092-0). Chapter five, survey test methods figure 5.7 on page 75 is something that looks like DCVG with a matched pair of CSE's. They call it Close Interval Survey Method No. 2.  The chapter author, Ronald L. Bianchetti (A.W.Peabody 1915-1998 was deceased when the 2nd edition came out) did not use the term DCVG and there are no references in the book.Cafe Nervosa (talk) 21:46, 2 June 2012 (UTC)

I looked through the index for Materials Performance from 1962 - 2007. I don't have copies of these old articles, but here are two candidates.Cafe Nervosa (talk) 22:25, 2 June 2012 (UTC)
 * MP April (No. 4) 1989 New Pipeline Coating Defect Surveying Equipment for Corrosion Protection Assessment, J. Mulvany

and
 * MP September (No. 9) 1967 Surface Potential Survey Can Detect Pipeline Corrosion Damage, E.P. Doremus, T.L. Canfield. It is my understanding that "surface potential surveys" is a cell to cell technique, like DCVG, but they were conducted on un-coated steel pipe and used to find areas of active corrosion, whereas the DCVG is used to locate coating defects, so ..

In Handbook of Cathodic Corrosion Protection 3rd Edition by von Beackmann, Schwenk & Prinz 1997 ISBN 0-88415-056-9 on page 129 a description of what appears to be DCVG and is has a reference which is [46] W. Schwenk und H. Ternes, gwf gas/erdgas 108, 749 (1967).