Yes, mulitple echo works very well on corroded surfaces. Pits on the front face can be filled with couplant and the probe used to straddle the pit. This will give the metal thickness from the bottom of the pit to the back wall. The couplant will be ignored as if it were a coating. This also means that a larger diameter probe can be used which gives better performance on returned ultrasound which has been scattered due to severe back wall corrosion.
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