Therefore, eddy current inspection of full length tube has been carried out in the light of in-service inspection per annum in Japan.

Status quo, bobbin type eddy current testing covers full length of tube as ordinary means and top of it, several kinds of inspection techniques are performed in accordance with detected defect mode, which causing dragged out inspection period.

In order to integrate several kinds of eddy current testing techniques and to shorten inspection period, Mitsubishi Heavy Industries (MHI) has succeeded in developing the latest Eddy Current Testing System and this newly developed system was already adapted in some real plant.

The features of newly developed Eddy Current Testing System are as follows. 1) Simultaneous Four Tubes Inspection System

• Mounting four sets of guide tubes / Finger walker type robot (MR III)
• Pusher & Puller which copes with four tubes at one time
• Newly Developed High Efficiency Data Acquisition Instrument (MIZ 60J) 2) Multi-coils type High Efficiency Eddy Current Probe

24ch multi-coils, installation of micro electric circuits Mutual-induction type coil arrangement / Differential type Detectability ; Equivalent to RPC probe Scanning speed ; Equivalent to Bobbin probe