ASTM E2491-08

This guide is intended to evaluate performance assessment of combinations of phased-array probes and instruments. It is not intended to define performance and acceptance criteria, but rather to provide data from which such criteria may be established.

Recommended procedures described in this guide are intended to provide performance-related measurements that can be reproduced under the specified test conditions using simple targets and the phased-array test system itself. It is intended for phased-array flaw detection instruments operating in the nominal frequency range of 1 MHz to 20 MHz, but the procedures are applicable to measurements on instruments utilizing significantly higher frequency components.

This guide is not intended for service calibration, or maintenance of circuitry for which the manufacturer’s instructions are available.

Implementation of specific assessments may require more detailed procedural instructions in a format of the using facility.

The measurement data obtained may be employed by users of this guide to specify, describe, or provide a performance criteria for procurement and quality assurance, or service evaluation of the operating characteristics of phased-array systems.

Not all assessments described in this guide are applicable to all systems. All or portions of the guide may be used as determined by the user.

1.1 This guide describes 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 comparing instruments and systems or, by periodic repetition, for detecting long-term changes in the characteristics of a given instrument or system that may be indicative of impending failure, and which, if beyond certain limits, will require corrective maintenance. Instrument characteristics measured in accordance with this guide are expressed in terms that relate to their potential usefulness for ultrasonic examinations. Other electronic instrument characteristics in phased-array units are similar to non-phased-array units and may be measured as described in E 1065 or E 1324.

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 must 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 and frequency of test, and report data required, must also 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 and connected alarm and auxiliary devices, primarily in cases where such a system is used repetitively without change or substitution. 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 Precautions relating to the applicability of the procedures and interpretation of the results are included.

1.9 Alternate procedures, such as examples described in this document, or others, may only be used with customer approval.

1.10 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.11 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 and health practices and determine the applicability of regulatory limitations prior to use.