Non-destructive testing—current capabilities and future directions

Abstract

The non-destructive testing (NDT) industry is reviewed, the major techniques being described and current development directions and challenges identified. Visual inspection is probably the most widely used NDT technique but it does not generally involve the purchase of dedicated NDT instrumentation so it does not appear in market estimates. The NDT market is dominated by the ‘big five’ techniques: radiography, ultrasonics, eddy current, magnetic particle and penetrant testing. There is considerable research and development effort in other areas, particularly for niche markets. Nondestructive testing is a mature industry, the global market size for equipment being around $1 billion. However, the cost to users greatly exceeds this since much inspection is highly labour intensive, and extensive preparation for inspection is often required, particularly in-service. There is therefore a continuing drive to increase the speed of inspection, to reduce the preparation required and, if possible, to inspect without the need to shut down operation. With some notable exceptions, it is possible to find most types of defect. However, it is frequently not cost effective to do the inspection, so driving down overall inspection costs is a major research and development aim. The other significant research and development areas are in improving inspection reliability and in finding solutions in cases where there is currently no available inspection technique.