This Standard specifies requirements for the following three types of image quality indicators (IQI) used in X-ray or gamma-ray radiographic examination of metals and includes recommendations for their use:(a) Wire IQI (W).(b) Step/hole IQI (SH).(c) Plaque/hole IQI (PH).NOTES:1 Advice and recommendations on wire IQI sensitivities are contained in Appendix A.2 Guidance and general information on materials of construction of IQIs, which should assist the users of this Standard, is contained in Appendix B.