Galvanic Corrosion – Expensive Problem for Telecom Industry

Galvanic Corrosion – Expensive Problem for Telecom Industry

As more and more critical devices are being installed at the top of GSM/UMTS towers, galvanic corrosion is becoming an increasingly costly problem within the industry.

If an installer were to accidentally lose hold of a diplexer while climbing a tower, the damage sustained by the metal object would be immediate and apparent. A new unit would be installed and the cost would be limited to the expense of the extra diplexer.But if instead he were to fasten an aluminium diplexer with a steel hose clamp and unwittingly allow contact between the two, the damage would not be noticeable until long after he had gone. By then, the cost of remedying the problem will have become far greater.

Costs millions

Scenarios like these are hardly the phenomenon of which Hollywood films are made. But in the business theatre of modern telecommunications, retrofits of antenna line components damaged by galvanic corrosion have been known to cost millions for network operators.TMAs, diplexers and triplexers (see www.allforsite.com) are all examples of equipment that, although vital to today’s mobile telecommunications, run the risk of deteriorating over time as water and other factors give rise to galvanic corrosion. Just how large the risk, and the problem, really is, depends most of all on the choice of materials with which these devices are made.

Aluminium under attack

Whenever two or more dissimilar metals are connected together in a corrosive environment (air, water, salt spray, etc), a galvanic couple is formed. On their own, each of these metals may be fairly resistant to corrosion, even when wet. But when in contact with each other, particularly in the presence of water, a corrosive electrolyte is formed whereby the most active metal becomes the anode and the other becomes the cathode. Deterioration of the nobler metal is slowed, but the anode corrodes far more rapidly than it normally would in the absence of a galvanic couple.In the case of aluminium and galvanised steel connected together in wet conditions, the aluminium component becomes the anode and corrodes through exfoliation or pitting. This is because aluminium has a far lower galvanic potential than both zinc and steel. With antenna towers, it is also generally believed that radiation and stray currents can speed up the corrosion process, although just how much is difficult to assess.

Need for greater awareness

Awareness of the problems caused by galvanic corrosion is still not as high as it probably should be, so more and more are finding out the hard way just how costly the problem can be.For many within the telecom industry, however, galvanic corrosion is already a notorious cause of failure with antenna line components. Some operators have even gone so far as to ban the use of aluminium components on antenna towers altogether. By doing so, they are likely to achieve more long-term protection for their network investments.

Reasons for our choice

At AllForSite, we selected Teracom’s diplexers because:
1/ it offers extremely low insertion loss with a typical value of 0.1 dB
2/ there is no need for weatherproofing
3/ after years of experience, we also know that the choice of product made of silver plated brass eliminates the risk of corrosion that we have described here above.So, we do not only sell products that provide the best performance, but we also like to deliver products that remain the best; With 10 years guaranty on their products, Teracom’s commitment to quality reaches our expectation and contribute to the only thing that matters to us: develop and maintain long term relationship with our customers.

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