The AS 5282 Test Ring (formerly known as the Ketos Test Ring) is a quick test method for ensuring an MPI process is
suitable for detecting a type of defect. The AS 5282 Ring consists of a ring with a series of drilled holes in different positions. The holes closest to the outer circumference simulate shallow defects while the holes closest to the centre of the ring simulate deep sub-surface discontinuities which would typically only be found using a DC current.