Definition - What does Attenuation mean?
Attenuation is a telecommunications term that refers to a reduction in signal strength that commonly occurs while transmitting analog or digital signals over long distances. Attenuation is historically measured in decibels (dB) but is also measured in terms of voltage.
Signal attenuation coatings are applied on underground pipelines and all materials where cathodic protection is implemented.
Corrosionpedia explains Attenuation
Attenuation signals help us understand coating defects on products that are protected from corrosion via cathodic protection. Alternating current (AC) signals are transferred through the pipelines during a signal attenuation coating (SAC) survey. When the AC signals are transmitted over a long distance pipeline, the signal strength decreases and the current leaks into the earth through the capacitive and resistive effects of the coating. A coating defect on the pipeline can be discovered when there is a sudden attenuation signal loss at a particular point on the pipeline. This signal loss will be of greater strength than the signal loss that occurs if there is no defect. This sudden loss of attenuation signal is detected by the survey equipment that is placed at various locations along the pipeline.