Crosshole sonic logging evaluates the integrity of the concrete of drilled shafts and other bored or cast-in-place deep foundations. Ultrasonic transmitters and receivers are inserted in the foundation and an instrument such as the Pile Dynamics' brand CHAMP-XV collects the data. Its software CHA-W analyses the propagation of the waves emitted by the transmitters, indicating potential concrete problems.

According to Pile Dynamics, tomography analysis with PDI-Tomo takes the examination many steps further, allowing a better estimate of the extent of irregularities or defects. It combines arrival time data from the scans of all pairs of tubes, analyses the data and displays it in various views.

Once CSL testing is complete and data is processed, the transition from CHA-W to PDI-Tomo is done in one seamless step. PDI-Tomo has been designed for fast data processing, improving the productivity of CHAMP-XV users. Program functions are intuitive and many features are automatic (for example, PDI-Tomo finds the depths where data suggests that a detailed investigation of integrity may be warranted). The PDI-Tomo output is highly customisable to fit the needs of each user, the company said.