METHOD AND DEVICE FOR JUDGING CONFORMITY/NON-CONFORMITY OF CONNECTION PART OF ALUMINUM CABLE STEEL REINFORCED

摘要

PROBLEM TO BE SOLVED: To make detectable whether a connection state is conforming or not by a non- destructive inspection method by comparing detection output that is obtained by performing detection with a specific phase from the output of a detection coil that is moved to the connection part of an aluminum cable steel reinforced with a specific interval with a standard value. SOLUTION: A mutual induction coil 11 of a detection means 10 is assembled in a flex saddle shape so that coils L1-L4 are wound and overlapped in a long circle diameter shape and an aluminum cable steel reinforced 1 is surrounded with a specific interval. The coils L1 and L3 that are retained in an air-core state are also in the same structure. Variable resistors R1 R2 are subjected to bridge connection to the secondary coils L3 and L4, and each pair is retained in an air-core state and zero-point adjustment is made. The other pair L2 and L4 are allowed to oppose a target, one pair L1 and L3 are retained in an air-core state, the primary coils L1 and L2 are energized by a low-frequency power supply for generating an eddy current in the target, and the difference in induction output appearing at the secondary coils L3 and L4 is taken out. A phase detection circuit 12 performs the phase detection of the output difference with a specific phase. A judgment circuit 14 compares the detection output with a specific threshold to judge whether connection is appropriate or not by judging the compression of an aluminum sleeve 7.