1.1 This practice describes a two-part procedure for electromagnetic evaluation on gear teeth on mill and kiln gear drives and pinions. The first part of this practice details the ability to detect 100 % of surface-breaking discontinuities only in the addendum, dedendum, and root area on both the drive side and non-drive side of the gear tooth using an eddy current array. The second part of the examination is to size or measure accurately the length and depth of any cracks found in these areas using electromagnetic methods. No other practice addresses the use of electromagnetic methods for the detection and sizing of surface-breaking discontinuities on mill and kiln ring gear teeth.

1.2 This practice is used only for crack detection, scuffing, wear patterns, and early signs of macro-pitting. It will not provide a full gear tooth analysis. Visual examination by an experienced gear specialist is the only way to characterize fully the failure modes present, their severity, and consequences. It is imperative that the analysis of the gear teeth is completed at the time of examination. Sending data offsite for analysis later is not recommended as potential failure modes could be missed from lack of in-situ visual examination.

1.3 Two technicians, one gear specialist, and a gear technician are typically required for this practice. One technician guides the probe and the other technician operate