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. Although most of the portable NDT instruments used by the Navy have either serial or analog output to make the data 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. There are many benefits of such a system. The inspector performance improves because he has access to the inspection data in image form, yet he can continue to inspect areas that would be difficult to reach using most scanners. All the benefits of manual inspection are retained, especially the ability to concentrate on critical areas.