ABSTRACT
In much of magnetic NDE, the inspected part forms part of a magnetic circuit, which may contain one or more air gaps. For example, in the case of a short part placed inside a coil so as to establish longitudinal magnetization (Fig. 16-1), much of the flux generated by the coiJ exists in air. Checks at points such as R indicate that the field intensity is greater when the part is removed, showing that the part is responsible for generating a field intensity that opposes the field of the coil This field, known as the demagnetization field, is discussed in this chapter, along with methods that are used in magnetic NDE for reducing it. Relatively large air component of flux loop for an encircling coil. (<italic>From the Nondestructive Testing Handbook</italic>, <italic>vol. 4, 2d ed. Reprinted with permission</italic>.) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315272993/937201b5-ee77-4453-9e41-7e220cf5cb89/content/fig16_1.tif"/>
