IEC 60424-4:2015 gives guidance on allowable limits of surface irregularities applicable to ring-cores in accordance with the relevant generic specification defined in IEC 60424-1. This standard is considered as a sectional specification useful in the negotiations between ferrite core manufacturers and customers about surface irregularities. This edition includes the following significant technical changes with respect to the previous edition:
- addition of crystallites in 3.1.3 and of pores in 3.1.4.