【国外标准】 Standard Guide for Detection and Evaluation of Discontinuities by Contact Pulse-Echo Straight-Beam Ultrasonic Methods

6.1 This guide provides procedures for the application of contact straight-beam examination for the detection and quantitative evaluation of discontinuities in materials.6.2 Although not all requirements of this guide can be applied universally to all examinations, situations, and materials, it does provide basis for establishing contractual criteria between the users, and may be used as a general guide for preparing detailed specifications for a particular application.6.3 This guide is directed towards the evaluation of discontinuities detectable with the beam normal to the entry surface. If discontinuities or other orientations are of concern, alternate scanning techniques are required.1.1 This guide covers procedures for the contact ultrasonic examination of bulk materials or parts by transmitting pulsed ultrasonic waves into the material and observing the indications of reflected waves. This guide covers only examinations in which one search unit is used as both transmitter and receiver (pulse-echo). This guide includes general requirements and procedures that may be used for detecting discontinuities, locating depth and distance from a point of reference and for making a relative or approximate evaluation of the size of discontinuities as compared to a reference standard.1.2 This guide complements Practice E114 by providing more detailed procedures for the selection and standardization of the examination system and for evaluation of the indications obtained.1.3 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.1.4 This guide 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 guide to establish the appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 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.