Low-cost, Position Indicator for Nondestructive Inspection C-Scanning

The Navy's nondestructive inspection mainly uses portable instruments with hand held ultrasonic or eddy current probes. The inspector makes the calls based on the data displayed on the instrument in real time without the aid of an image. This makes it difficult to distinguish between flaws and normal substructures and to quantify the size, shape and severity of the flaws. The problem can be greatly alleviated if a C-scan image of the inspection area is generated using the inspection data. The portable NDT instruments used by the Navy have either serial or analog output to make the data available, but currently available mechanical scanners are too cumbersome, expensive and complicated for field use on complex structures. An effective solution is to track the position of hand held probes using remote sensors and combine both the position and NDT data on a laptop computer C-scan display. Phase I of this project showed the advantages and limitations of two simple and low cost locating devices. Phase II will support the development of two and three dimensional positioning systems based on the technologies that were shown to be effective in Phase I.