ISO/TC 135/SC 3 - Ultrasonic testing

This document gives general provisions for applying ultrasonic testing with arrays using FMC/TFM techniques and related technologies. It is intended to promote the adoption of good practice either at the manufacturing stage or for in-service testing of existing installations or for repairs. Some examples of applications considered in this document deal with characterization and sizing in damage assessment. Materials considered are low-alloyed carbon steels and common aerospace grade aluminium and titanium alloys, provided they are homogeneous and isotropic, but some recommendations are given for other materials (e.g. austenitic ones). This document does not include acceptance levels for discontinuities. For the application of FMC/TFM to testing of welds, see ISO 23864.

This document defines terms used in ultrasonic testing with arrays. This includes phased array technology and signal processing technology using arrays, e. g. the full-matrix capture (FMC) (3.3.1.28) and the total focusing technique (TFM) (3.3.1.35).

This document specifies methods, tolerances and acceptance criteria for verifying the performance of combined ultrasonic test equipment (i.e. instrument, probes and cables connected) by the use of appropriate standard calibration blocks. These methods are specifically intended for manual test equipment, i.e. ultrasonic instruments according to ISO 22232-1, and for manual ultrasonic non-destructive testing with single- or dual-transducer probes according to ISO 22232-2. This document is also applicable for multi-channel instruments. For automated test equipment, different tests can be needed to ensure satisfactory performance. The specified methods are intended for the use by operators working under site or shop floor conditions. These methods are not intended to prove the suitability of the equipment for particular applications. This document excludes ultrasonic instruments for continuous waves. This document also excludes ultrasonic phased array systems, see e. g. ISO 18563-3. If a phased array instrument is used in combination with single- or dual-transducer probes, this document is applicable to this combination.

This document specifies the characteristics of probes used for non-destructive ultrasonic testing in the following categories with centre frequencies in the range of 0,5 MHz to 15 MHz, focusing or without focusing means: a) single- or dual-transducer contact probes generating longitudinal and/or transverse waves; b) single-transducer immersion probes. Where material-dependent ultrasonic values are specified in this document they are based on steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves, and (3 255 ± 30) m/s for transverse waves. This document excludes periodic tests for probes. Routine tests for the verification of probes using on-site procedures are given in ISO 22232-3. If parameters in addition to those specified in ISO 22232-3 are to be verified during the probe's life time, as agreed upon by the contracting parties, the procedures of verification for these additional parameters can be selected from those given in this document. This document also excludes ultrasonic phased array probes, therefore see ISO 18563-2.

This document specifies methods and acceptance criteria within the frequency range of 0,5 MHz to 15 MHz, for assessing the electrical performance of digital ultrasonic instruments for pulse operation using A-scan display, for manual ultrasonic non-destructive testing with single- or dual-transducer probes. This document is also applicable for multi-channel instruments. This document can partly be applicable to ultrasonic instruments in automated systems, but other tests can be needed to ensure satisfactory performance. This document excludes ultrasonic instruments for continuous waves. This document also excludes ultrasonic phased array instruments, see e.g. ISO 18563-1. If a phased array instrument has dedicated connectors for single- or dual-transducer probes this document is applicable for these channels.

This document specifies the application of phased array technology for the semi- or fully automated ultrasonic testing of fusion-welded joints in steel parts with thickness values between 3,2 mm and 8,0 mm. This meets the typical range of tube wall thickness values in boilers, which is an important application of this testing technology. The minimum and maximum value of the wall thickness range can be exceeded, when testing level "D" of this document is applied. This document applies to full penetration welded joints of simple geometry in plates, tubes, pipes, and vessels, where both the weld and parent material are low-alloy and/or fine grained steel. NOTE "Semi-automated testing" encompasses a controlled movement of one or more probes on the surface of a component along a fixture (guidance strip, ruler, etc.), whereby the probe position is unambiguously measured with a position sensor. The probe is moved manually. "Fully automated testing" includes mechanized propulsion in addition. Where material-dependent ultrasonic parameters are specified in this document, they are based on steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves, and (3 255 ± 30) m/s for transverse waves. It is necessary to take this fact into account when testing materials with a different velocity. This document provides guidance on the specific capabilities and limitations of phased array technology for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. Ultrasonic phased array technology can be used as a stand-alone technique or in combination with other non-destructive testing (NDT) methods or techniques, during manufacturing and testing of new welds/repair welds (pre-service testing). This document specifies two testing levels: — level "C" for standard situations; — level "D" for different situations/special applications. This document describes assessment of discontinuities for acceptance purposes based on: — height and length; — amplitude (equivalent reflector size) and length; — go/no-go decision. This document does not include acceptance levels for discontinuities.

ISO 16809:2017 specifies the principles for ultrasonic thickness measurement of metallic and non-metallic materials by direct contact, based on measurement of time of flight of ultrasonic pulses only.

The information in ISO/TS 16829:2017 covers all kinds of ultrasonic testing on components or complete manufactured structures for either correctness of geometry, for material properties (quality or defects), and for fabrication methodology (e.g. weld testing). ISO/TS 16829:2017 enables the user, along with a customer specification, or a given test procedure or any standard or regulation to select: - ultrasonic probes, probe systems and controlling sensors; - manipulation systems including controls; - electronic sub-systems for the transmission and reception of ultrasound; - systems for data storage and display; - systems and methods for evaluation and assessment of test results. With regard to their performance, ISO/TS 16829:2017 also describes procedures for the verification of the performance of the selected test system. This includes - tests during the manufacturing process of products (stationary testing systems), and - tests with mobile systems.

ISO 19285:2017 specifies acceptance levels for the phased array ultrasonic testing technique (PAUT) of full penetration welds in ferritic steels of minimum thickness of 6 mm which correspond to the quality levels of ISO 5817. These acceptance levels are applicable to indications classified in accordance with ISO 13588.

ISO 18563-2:2017 specifies the characterization tests performed at the end of the fabrication of a phased array probe. It defines both methodology and acceptance criteria. ISO 18563-2:2017 is applicable to the following phased array probes used for ultrasonic non-destructive testing in contact technique (with or without a wedge) or in immersion technique, with centre frequencies in the range 0,5 MHz to 10 MHz: a) non-matrix array probes: - linear; - encircling; - partial annular sectorial (type "daisy"); b) 2D-matrix array probes. ISO 18563-2:2017 does not give methods and acceptance criteria to characterize the performance of an ultrasonic phased array instrument or the performance of a combined system. These are given in ISO 18563?1 and in ISO 18563?3.

ISO 16946:2017 specifies the dimensions, material, and manufacture of a step wedge steel block for the calibration of ultrasonic instruments.

ISO 5577:2017 defines the terms used in ultrasonic non-destructive testing and forms a common basis for standards and general use. This document does not cover terms used in ultrasonic testing with phased arrays. NOTE Terms for phased array ultrasonic testing are defined in EN 16018.

ISO 19675:2017 specifies requirements for the dimensions, material and manufacture of a steel block for calibrating ultrasonic test equipment used in ultrasonic testing with the phased array technique.

ISO 18211:2016 specifies a method for long-range testing of carbon and low-alloy steel above-ground pipelines and plant piping using guided ultrasonic waves with axial propagation applied on the entire circumferential pipe section, in order to detect corrosion or erosion damage. The guided wave testing (GWT) method allows for fast inspection of above-ground pipelines, plant piping and cased road crossings, giving a qualitative screening and localization of probable corroded and eroded areas. GWT is typically performed on operating piping systems. ISO 18211:2016 is applicable to the following types of pipes: a) above-ground painted pipelines; b) above-ground insulated pipelines; c) painted plant piping; d) insulated plant piping. NOTE Pipe sections within road crossings with external casings (without bitumen or plastic coating) are a special case of buried pipe where there is no soil pressure on the OD of the pipe. ISO 18211 :2016 applies to these cased road crossings. Other types of pipes not included in the above list need dedicated approaches due to increased complexity.

ISO 18563-3:2015 addresses ultrasonic test systems implementing linear phased array probes, in contact (with or without wedge) or in immersion, with centre frequencies in the range of 0,5 MHz?10 MHz. It provides methods and acceptance criteria for verifying the performance of combined equipment (i.e. instrument, probe and cables connected). The methods described are suitable for users working under on-site or shop floor conditions. Its purpose is for the verification of the correct operation of the system prior to testing, and also the characterization of sound beams or verification of the absence of degradation of the system. The methods are not intended to prove the suitability of the system for particular applications, but are intended to prove the capability of the combined equipment to generate ultrasonic beams according to the settings used. The calibration of the system for a specific application is outside of the scope of part of ISO 18563 and it is intended that it be covered by the test procedure. ISO 18563-3:2015 does not address the following: - encircling arrays; - series of apertures having a different number of elements; - different settings for transmitting and receiving (e.g. active aperture, number of active elements, delays); - techniques using post-processing of the signals of individual elements in a more complex manner than a simple delay law (e.g. full matrix capture).

ISO 18563-1:2015 identifies the functional characteristics of a multichannel ultrasonic phased array instrument used for phased array probes and provides methods for their measurement and verification. ISO 18563-1:2015 can partly be applicable to ultrasonic phased array instruments in automated systems, but then, other tests might be needed to ensure satisfactory performance. When the phased array instrument is a part of an automated system, the acceptance criteria can be modified by agreement between the parties involved. ISO 18563-1:2015 gives the extent of the verification and defines acceptance criteria within a frequency range of 0,5 MHz to 10 MHz. The evaluation of these characteristics permits a well-defined description of the ultrasonic phased array instrument and comparability of instruments.

This International Standard specifies requirements for the dimensions, material and manufacture of a steel block for calibrating ultrasonic test equipment used in manual testing.

ISO 16823:2012 specifies the principles of transmis­sion techniques. Transmission techniques can be used for: a) detection of imperfections; b) determination of attenuation. The general principles required for the use of ultrasonic examina­tion of in­dustrial products are described in ISO 16810. The transmission technique is used for examination of flat pro­ducts, e.g. plates and sheets. Further, it is used for examinations e.g.: 1) where the shape, dimensions or orientation of possible imperfections are unfavourable for direct reflection; 2) in materials with high attenuation; 3) in thin products.

ISO 16831:2012 specifies methods and acceptance criteria for assessing the performance of instruments for measuring thickness using pulse-echo ultrasound. ISO 16831:2012 covers both direct (digital) reading and waveform display types using single or dual element probes. ISO 16831:2012 can be used for verifying equipment covered by EN 12668 when used for thickness measurement.

ISO 16826:2012 defines the principles for tandem‑ and longitudinal-longitudinal-transverse (LLT) wave‑examination for the detection of discontinuities perpendicular to the surface. The general principles required for the ultrasonic examination of industrial products are described in ISO 16810. A list of symbols and equations is given in ISO 16811. The tandem‑ or LLT‑examination should be used for the detection of planar discontinuities with distance to the surface greater than 15 mm. ISO 16826:2012 has been prepared for the examination of metallic materials with a thickness between 40 mm and 500 mm with parallel or concentric surfaces. It can, however, be used for other materials and smaller thickness provided special measures are taken.

ISO 16811:2012 specifies the general rules for setting the timebase range and sensitivity (i.e. gain adjustment) of a manually operated ultrasonic flaw detector with A-scan display in order that reproducible measurements may be made of the location and echo height of a reflector. ISO 16811:2012 is applicable to techniques employing a single contact probe with either a single or twin transducers, but excludes the immersion technique and techniques employing more than one probe.

ISO 16828:2012 defines the general principles for the application of the time-of-flight diffraction (TOFD) technique for both detection and sizing of discontinuities in low alloyed carbon steel components. It can also be used for other types of materials, provided the application of the TOFD technique is performed with necessary consideration of geometry, acoustical properties of the materials, and the sensitivity of the examination. Although it is applicable, in general terms, to discontinuities in materials and applications covered by ISO 16810, it contains references to the application on welds. This approach has been chosen for reasons of clarity as to the ultrasonic probe positions and directions of scanning. Unless otherwise specified in the referencing documents, the minimum requirements of ISO 16828:2012 are applicable. Unless explicitly stated otherwise, ISO 16828:2012 is applicable to the following product classes as defined in ISO 16811: a) class 1, without restrictions; b) classes 2 and 3, restrictions apply as stated in Clause 9. The inspection of products of classes 4 and 5 requires special procedures. These are also addressed in Clause 9. Techniques for the use of TOFD for weld inspection are described in ISO 10863. The related acceptance criteria are given in ISO 15626.

ISO 16810:2012 defines the general principles required for the ultra­sonic examination of industrial products that permit the trans­mis­sion of ultrasound. The specific conditions of application and use of ultrasonic examination, which depend on the type of product examined, are described in documents which could include: a) product standards; b) specifications; c) codes; d) contractual documents; e) written procedures. Unless otherwise specified in the referencing documents the minimum requirements of ISO 16810:2012 are applicable. ISO 16810:2012 does not define: 1) extent of examination and scanning plans; 2) acceptance criteria.

ISO 16827:2012 specifies the general principles and techniques for the characterization and sizing of previously detected discontinuities in order to ensure their evaluation against applicable acceptance criteria. It is applicable, in general terms, to discontinuities in those materials and applications covered by ISO 16810.

ISO7963:2005 specifies the dimensions, material, manufacture and methods of use for calibration block No. 2 for calibrating and checking ultrasonic testing equipment

ISO 16946:2015 specifies the dimensions, material, and manufacture of a step wedge steel block for the calibration of ultrasonic instruments.

ISO 12715:2014 introduces two metal reference blocks, the hemicylindrical-stepped (HS) block and the side-drilled-hole (SDH) block. ISO 12715:2014 establishes procedures for measuring the sound beam profiles generated by probes in contact with the test object. The probes include straight-beam, angle-beam (refracted compressional and refracted shear wave), focused beam, and dual-element probes. The side dimension of the probe has to be no greater than 25 mm. The methodology of ISO 12715:2014 provides guidelines for probes to be used for different metals including forged or rolled steel, aluminium, or titanium alloy products. The frequency range of the probes used in ISO 12715:2014 extends from 1 MHz to 15 MHz, where 1 MHz to 5 MHz is best suited for steels and 5 MHz to 15 MHz is best for fine grain structured alloys such as aluminium products.

ISO 16809:2012 specifies the principles for ultrasonic thickness measurement of metallic and non-metallic materials by direct contact, based on measurement of time-of-flight of ultrasonic pulses only.

ISO 18175:2004 describes procedures for evaluating the following performance characteristics of ultrasonic pulse-echo examination instruments: horizontal limit and linearity; vertical limit and linearity; resolution-entry surface and far surface; sensitivity and noise; accuracy of calibrated gain controls. ISO 18175:2004 may be used for the evaluation of a complete examination system, including transducer, instrument, interconnections, fixtures and connected alarm and auxiliary devices, primarily in cases where such a system is used repeatedly without change or substitution. This International Standard is not intended to be used as a substitute for calibration of a system to inspect any given material.

ISO 12710 describes a set of procedures for the measurement of any performances in an ultrasonic test instrument that has a display screen. This International Standard establishes the procedures for measuring performance characteristics of components of pulse-echo ultrasonic non-destructive testing instruments including both analog and digital type instruments with screen displays. The aim is to establish uniformity of evaluation techniques, to form a basis for data correlation and for interpretation of results obtained from different laboratories and at different times. Note that ISO 12710 establishes no acceptance criteria; such criteria should be specified by user parties. The usual components of ultrasonic non-destructive testing instruments and the performance characteristics for which procedures for measuring these characteristics are described including: line regulation; battery discharge time; battery charge time; pulse shape; pulse amplitude; pulse rise time; pulse length; pulse frequency spectrum; vertical linearity; frequency response; noise and sensitivity; dB controls; horizontal linearity; clock (pulse repetition rate); delay and width; resolution; alarm level; gain uniformity; analog output; back-echo gate linearity.

Establishes material and dimensions of the reference block. The tolerances on all dimensions are 0,1 mm.