Increasing demands for the inspection of pipes and tubes in production require fully automated testing with 100% coverage. In parallel to challenging specifications concerning detection and measurement accuracy, the test system must perform at high test speeds to cope with the throughput requirements of the production. To accomplish this, parallel phased-array technology is the key technology.

The ROWA WT system is an industrial solution for the high-performance inline inspection of tubes and pipes containing wall thickness measurement suitable for typical seamless pipes, lamination detection and inner wall deformation.
The different ROWA types cover a dimension range from 1 1/6 inch ( 30 mm) to 7 inch (178 mm) for the smallest and from 5 inch (127 mm) to 16 inch (406 mm) for the largest type and a minimum wall thickness down to 0.14 inch (3.5 mm). Based on the long-standing experience in the field, a scrutinized method was developed allowing the flexible adaptation to different diameters and to other external impacts such as guidance.

Examples from the field will demonstrate the high precision and repeatability of the system. The accuracy of the wall thickness measurement is about 0.002 inch (0.05 mm). Detection via time-of flight evaluations allow a very good near surface resolution of 0.4 inch (1 mm), amplitude based detection starts around 0.8 inch (2 mm) and 1.2 inch (3 mm) from the inner and surface, respectively. An evaluation of the backwall echo sequence allows the identification of inner wall deformations. In addition to classical UT measurements addressed with such machines, the ROWA WT system also features further geometry measurements such as eccentricity, inner and outer diameter or ovality. Aspects of data handling and analysis needed for precise results and high sorting accuracy will be outlined at the end. Moreover, perspectives of further data evaluation for quality assurance and as input for process optimization will be discussed.