Omniflex develops wireless cathodic protection monitor
Remote monitoring specialist Omniflex, launches iGAL, a battery-powered instrument for remotely monitoring and testing galvanic cathodic protection (CP) installations wirelessly via the web.
It is designed to help asset managers monitor the corrosion of embedded metal structures while cutting down the need to physically visit the site to undertake time-consuming surveys.
It has a battery life of up to six years and a weatherproof enclosure to protect embedded metal structures from corrosion. The iGAL connects the structure being protected to a series of anodes made from a metal alloy, such as magnesium, aluminium or zinc, that has more negative electrode potential than the steel being protected, making it more electrochemically active. This allows the galvanic anode to be consumed by corrosion, rather than damage the structure.
The iGAL was developed as an alternative to conventional impressed current cathodic protection (ICCP) systems where an external DC power source is used to protect the structure.
“While impressed current systems have featured remote monitoring for many years due to their scale and complexity, most galvanic CP installations are not regularly monitored, if at all,” explains David Celine, managing director of Omniflex. “The need to meet more demanding compliance and reporting targets means that experts regularly need to visit these sites to conduct tests to ensure the galvanic system is working.”
iGAL has been designed to allow users to remotely monitor strategic assets located in areas with a higher risk of corrosion, such as bridges, marine wharves and heritage buildings, by preventing corrosion in steel CP assets, using three common monitoring techniques. The system can measure up to four of each of these methods. For example, four anode currents, four reference-electrode voltages and four corrosion-coupon currents can be measured.
“iGAL takes this a step further, allowing users to remotely disconnect the anodes from the structure to carry out tests, such as instant-off potential and depolarisation, which can take days to complete,” adds Celine. It can be set to perform these tests automatically based on a schedule using a web portal over a 4G LTE mobile network. The results are securely stored and can be downloaded.
For monitoring reference electrodes, iGAL uses high-impedance voltmeter technology, and for corrosion coupons iGAL features four zero-resistance ammeter inputs. This is the most direct way of measuring the rate of corrosion.