R/D Tech (Canada), AECL (Canada) and NEL (Japan) jointly worked on the development of a new high performance array probe. EDF (France), EPRI (U. S. ), and other companies have also contributed to this development. The completed probe, which was named X-probe, is a transmit/receive type array probe equipped with pancake coils on its entire periphery and a multiplexer which continuously switches transmit and receive modes of each coil. Since the probe has the channels which are optimized for the detection of axial and circumferential cracks respectively, it is highly sensitive to any cracks regardless of their direction. In addition, the probe can pass the U-bend portion and this enables a full length inspection at speed equivalent to or higher than a bobbin type probe.

In this study, basic function tests were conducted using this new probe and a newly developed high performance inspection system (TC-7700: manufactured by R/D Tech). At the same time, detectability tests were conducted using samples with EDM notches and artificial SCC. In addition, comparison tests with the +Point probe and other types of rotating probes were also conducted.

The results indicated that the high performance probe, which has been newly developed, showed better detectability than pancake rotating probes. It was also revealed that the new probe could provide almost the same signals as those provided by a normal transmit/receive coil and show sufficient information about the results of analyses on the three-dimensional display window in a similar manner as rotating probes.