| Maintenance strategies: In
the bigger picture, corrosion monitoring represents a part of maintenance and asset
management. The role and importance of corrosion monitoring differs in corrective,
preventive and predictive maintenance strategies.
| Corrective maintenance can be described
as "fixing" when a problem occurs. Maintenance experts have pointed out that
there may be a "natural tendency" to intuitively follow this approach, even
though it may be (cost) ineffective in ensuring reliability. This maintenance strategy
is reactive only, and corrosion monitoring programs do not feature prominently in this
approach. The emphasis is more on repairs, emergency procedures and use of back-up systems
after a problem has arisen. A household analogy would be servicing a car only for repairs,
when components have failed. |
| Preventive maintenance refers to repair
and maintenance actions before a failure occurs. Scheduled inspections for corrosion
damage feature prominently, to facilitate these preemptive actions. Ideally, the planned
intervals of preventive maintenance are arranged so that corrective action is taken just
before significant damage would set in otherwise. Corrosion monitoring programs may assist
in optimizing the planned maintenance intervals. A household analogy would be oil and
transmission fluid changes on a car at regular intervals to minimize engine and
transmission component failures. |
| Predictive maintenance actions are
based on the actual condition, rather than on fixed schedules. Corrosion sensors and
monitoring activities are important in the context of creating a "smart
structure", for obtaining information on its actual condition. The aim is to minimize
(or even eliminate) unnecessary maintenance and inspection activities and to focus
maintenance efforts when and where they are most needed. Overall, this strategy is of a
highly proactive nature, with the emphasis on predicting when and where maintenance
actions are required. An automotive analogy would be oil and transmission fluid changes
based on the actual driving and oil/fluid characteristics, rather than at fixed regular
intervals. City stop/start driving may warrant more frequent changes compared with
continuous, long-distance freeway travel. (A well-known European luxury car manufacturer
has actually recently advertised such a system ".....monitors oil quality and
driving habits, so you only come in for service when you actually need to.") |
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