Define Non-destructive inspection of Concrete Substructures?

If there is evidence of significant deterioration, then a Level III inspection, involving either non-destructive or destructive tests, may be required. Some of the NDT equipments that can be used for underwater examination of concrete are:

- Rebound Hammer

- Ultrasonic system

- Magnetic Rebar Locator

Each instrument consists of an underwater sensor connected to a topside deck unit through an umbilical cable. The deck unit contains the signal conditioning electronics and data acquisition system. To operate the instrument, the diver has to position the underwater sensor on a previously cleaned portion of the structure surface, and person topside operates the data acquisition system in order to collect and store the data.