1.1 This practice covers a procedure for fabrication and control of metal alloy reference blocks used in ultrasonic examinations that contain flat bottom holes (FBH).

1.2 These blocks may be used for checking the performance of ultrasonic examination instrumentation and search units and for standardization and control of ultrasonic examination of metal alloy products.

1.3 The reference blocks described are suitable for use with either the direct-contact method or immersion pulse-echo ultrasonic methods.

1.4 Standard sets are described for flat surface sound entry; the Basic set, Area-Amplitude set, and Distance Amplitude set.

1.5 The requirements for FBH fabrication may be applied to round bar/billet reference standards and reference standards fabricated from other product forms.

1.6 This practice does not specify reference reflector sizes or product rejection limits. It does describe fabrication practices and applied tolerances. In all cases of conflict between this practice and customer specifications, the customer specification shall prevail.

1.7 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.8 This practice has incorporated the requirements of Practice E428 and Guide E1158. Reference standards that were manufactured under Practice E428 and Guide E1158 comply with the requirements of this practice.

1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.10 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.