Differential eddy current converter for nondestructive testing - has inductively coupled field and detector windings incorporating 4-pole network

摘要

Converter detecting faults in objects manufactured from electrically conducting material, is used in an electromagnetic instrument for non-destructive quality control of elongated components. The circuit consists of a field winding (11) and a detecting winding (2) which are inductively coupled. The component to be checked will pass between the two windings. The field winding is divided into two hollow single layer sections (3,4) which are connected in series. The length of each section is three times the diameter. The detector winding (2) is divided into two hollow single layer sections (5,6) connected in series. They are connected in the opposite sense and the junction is connected to earth. There is a 4-pole network with two poles connected in parallel with the power winding. The other two terminals of the 4-pole network are earthed.