ASTM E 2491:2023

1.1 This guide covers procedures for evaluating some performance characteristics of phased-array ultrasonic examination instruments and systems. 1.2 Evaluation of these characteristics is intended to be used for either comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system. Significant changes may be indicative of impending failure, and, if beyond certain limits, will require corrective maintenance. Some electronic instrument characteristics in phased-array units are similar to non-phased-array units and may be measured as described in Practice E1065 or Guide E1324 . 1.3 Ultrasonic examination systems using pulsed-wave trains and A-scan presentation (rf or video) may be evaluated. 1.4 This guide establishes no performance limits for examination systems; if such acceptance criteria are required, these shall be specified by the using parties. Where acceptance criteria are implied herein, they are for example only and are subject to more or less restrictive limits imposed by customer's and end user's controlling documents. 1.5 The specific parameters to be evaluated, conditions, frequency of test, and report data required shall be determined by the user. 1.6 This guide may be used for the evaluation of a complete examination system, including search unit, instrument, interconnections, scanner fixtures, connected alarm, and auxiliary devices. This guide is not intended to be used as a substitute for calibration or standardization of an instrument or system to inspect any given material. 1.7 Required test apparatus includes selected test blocks and position encoders in addition to the instrument or system to be evaluated. 1.8 Alternate procedures, such as examples described in this document, or others, may only be used with customer approval. 1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.10 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. 1.11 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.

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