About DCVG and how it all began

 DC Voltage Gradient Technology and Supply Ltd.

DC Voltage Gradient Technology and Supply Ltd. is the worlds leading company in DC Voltage Gradient Technology with very active research into the technology and the design and manufacturing of DCVG and CIPS survey instruments.


What is DCVG

DCVG stands for Direct Current Voltage Gradient, which is a survey technique used for locating coating faults that can be further used for assessing the effectiveness of corrosion protection on buried steel structures, usually oil, natural gas, and water or any steel structures that have CP  (Corrosion Protection) applied to it. Pipelines are monitored using this technique to aid the user to locate coating faults and also highlight any kind of deficiencies in their cathodic protection.


John Mulvany and Dr John Leeds defining and testing early DCVG Equipment

Where it began

DC Voltage Gradient Technology and Supply Ltd was established in 1994 by Dr John Leeds.  As a senior corrosion engineer in the 1980's Dr John Leeds was responsible for some of the major oil and gas pipelines in Australia. Dr John Leeds researched into different pipeline survey techniques to be used as a way of  minimising corrosion. Today, the DCVG technique is universally accepted throughout the pipeline industry in 71 countries. Dr John Leeds was the first person to train people worldwide to use the DCVG technique. 


Dr John Leeds Using the DCVG technique in the 1990's


Present Day

DC Voltage Gradient Technology and Supply Limited has the next Generation of the Leeds family managing the company. Dr Sarah Leeds has been visiting pipelines and learning off her father since her teens. In her early years she went out and performed DCVG surveys in many countries around the world. After that she went on to study a Phd in corrosion and Cathodic Protection. A big part of her studies involved researching passive films that form on metals and pipelines as a direct consequence of applying cathodic protection. Dr Sarah Leeds is now leading the research and development of new products involving Corrosion and Cathodic Protection. She has co-written many journal articles over the years with her father and has recently completed a chapter in Winston Revie book, Oil and gas Pipelines Integrity and safety Handbook. These days she has taken over her fathers role for training people throughout the world in DCVG and Cathodic Protection of Pipelines. She is involved in Industry Standard Committee Meetings and gets asked to speak at Conferences to present her research. 

Evolution of the DCVG Meter


          1990 - 1994


1995 - 2010



2010 - Onwards



2012 - Onwards



Background information

Steel structures will eventually corrode if not provided with corrosion control such as CP and the rate of corrosion can be unacceptably rapid in some soils or where exposed to salt water. Usually pipes are covered in more than one protective coating corrosion will still be likely to happen anyway with buried pipes. Before the use of DCVG, assessing the condition of the pipeline was indirect and could lead to expensive excavations but with DCVG you can pinpoint coating faults and their severity avoiding disturbance to the pipeline.



The Surveyor will be able to pinpoint the exact epicentre of the coating fault. Electrical measurement will be made between the epicentre and remote earth to determine characterisations of the coating faults will pinpoint those for repair. 





Survey In Any Environment