Ultrasonic multi-skip tomography for pipe inspection

The inspection of wall loss corrosion is difficult at pipe support locations due to limited accessibility. However, the recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are...

Multi-skip tomographic inversion

Inspection of corrosion at pipe support locations is difficult because of accessibility limitations. Recently a screening technique has been developed called Multi-Skip ultrasonics. The method utilizes a pitch-catch set-up. Shear waves are transmitted that reflect multiple times in the pipe wall, from which integral wall thickness information is...

Ultrasonic characterization of defects in steel using Multi-SAFT imaging and neural networks

Due to the recent improvements in nondestructive inspection (NDI) techniques, even small or weak inhomogeneities can be detected and discrimination between critical and non-critical defects becomes more crucial. In practice, welded regions of steel components are of special interest. Characterizing a detected inhomogeneity may be done by using...

Ultrasonic imaging with multi-SAFT: Nondestructive characterization of defects in steel components

At the end of 1988 a research project was started to develop a practical, high-resolution imaging method for ultrasonic NDI, based on the Synthetic Aperture Focusing Technique (5APr). This project was initiated by the TNO Institute of Applied Physics and two major companies in The Netherlands. As conventional single-transducer measurements do...

Opto-acoustical inspection of surface layers

Opto-akoestische bepaling van laagdikten met behulp van Rayleighgolf dispersie-data

Het onderzoek betreft de evaluatie van een contactloze en niet-destructieve testmethode met behulp van lasertechnieken. Er is een meetopstelling gerealiseerd, waarmee de mogelijkheden zijn onderzocht de laagdikte van een enkele, homogene en isotrope laag op een homogeen en isotroop substraat te bepalen uit Rayleighgolf dispersie-data. Uit het...