METHOD AND APPARATUS FOR NON-DESTRUCTIVELY INSPECTING WELDED PART

PROBLEM TO BE SOLVED: To provide a method and an apparatus for non-destructively inspecting a welded part capable of accurately measuring an electric resistance of all welded parts without cutting an annularly welding material. SOLUTION: The method for non-destructively inspecting the welded part comprises the steps of simultaneously supplying currents having substantially equal amplitudes in a reverse direction to both ends of two welded parts R1, R2 in an annular group 1 to thereby measure absolute values of electric resistances of the two welded parts, connecting in parallel a first current route 51 including one of the two welded parts and a second current route 52 including other one to supply a predetermined current between connecting points C1 and C2 of the first and second routes, measuring voltages generated at the respective welded parts to thereby measure a relative value of the electric resistances of the welded parts, calculating absolute values of the resistances of the respective welded parts based on these absolute values and the relative values, and inspecting the welding strengths.