CEN/TC 138/WG 1 - Ionizing radiation testing

This document specifies a method for the measurement of effective focal spot dimensions above 0,1 mm of X-ray systems up to and including 1000 kV tube voltage by means of the pinhole camera method with digital evaluation. The tube voltage applied for this measurement is restricted to 200 kV for visual film evaluation and may be selected higher than 200 kV if digital detectors are used.
The imaging quality and the resolution of X-ray images depend highly on the characteristics of the effective focal spot, in particular the size and the two dimensional intensity distribution as seen from the detector plane. This method compared to the others in the EN 12543 series allows to obtain an image of the focal spot and to see the state of it (e.g. cratering of the anode).
This test method provides instructions for determining the effective size (dimensions) of standard (macro focal spots) and mini focal spots of industrial X-ray tubes. This determination is based on the measurement of an image of a focal spot that has been radiographically recorded with a "pinhole" technique and evaluated with a digital method.
For the characterization of commercial X-ray tube types (i.e. for advertising or trade) it is advised that the specific FS (Focal spot) values of Annex A are used.

This document describes the test method for determining residual stresses in polycrystalline materials by neutron diffraction. It is applicable to both homogeneous and inhomogeneous materials including those containing distinct phases.
The principles of the neutron diffraction technique are outlined. Suggestions are provided on:
—          the selection of appropriate diffracting lattice planes on which measurements should be made for different categories of materials,
—          the specimen directions in which the measurements should be performed, and
—          the volume of material examined in relation to the material grain size and the envisaged stress state.
Procedures are described for accurately positioning and aligning test pieces in a neutron beam and for precisely defining the volume of material sampled for the individual measurements.
The precautions needed for calibrating neutron diffraction instruments are described. Techniques for obtaining a stress-free reference are presented.
The methods of making individual measurements by neutron diffraction are described in detail. Procedures for analysing the results and for determining their statistical relevance are presented. Advice is provided on how to determine reliable estimates of residual stresses from the strain data and on how to estimate the uncertainty in the results.

ISO 16526-2:2011 specifies a constancy check of a X-ray system where mainly the X-ray voltage is checked and also the tube current and the constitution of the target which can be changing due to ageing of the tube.
The thick filter method is based on a measurement of the dose rate behind a defined thick filter using defined distances between the X-ray tube, the filter and the measuring device.
This method is very sensitive to changes of the voltage, but it does not provide an absolute value for the X-ray tube voltage. Therefore, a reference value is needed and, it is recommended to find this reference, for example, within the acceptance test of the system.
The thick filter method is a rather simple technique and may be applied by the operator of an X-ray system to perform regularly a constancy check of the system.
The method can also be applied for consistency checks after changing components which may affect the X-ray tube voltage.
This method can be applied for all types of X-ray systems, i. e. for constant potential, half wave and impulse wave generators with a tube current larger than 1 mA.

ISO 14096-2:2005 specifies three film-digitisation quality classes for the requirements of non-destructive testing. The selected class depends on the radiation energy, penetrated material thickness and the quality level of the original radiographic film. ISO 14096-2:2005 does not address signal processing, display and storage of the digitised data.

ISO 16526-1:2011 specifies a method for the direct and absolute measurement of the average high voltage of constant potential (DC) X-ray systems on the secondary side of the high voltage generator. The intention is to check the correspondence with the indicated high voltage value on the control unit of the X-ray system.
This method is applied to assure a reproducible operation of X-ray systems because the voltage influences particularly the penetration of materials and the contrast of X-ray images and also the requirements concerning the radiation protection.

ISO 16526-3:2011 specifies the test method for a non-invasive measurement of X-ray tube voltages using the energy spectrum of X-rays (spectrometric method). It covers the voltage range from 10 kV to 500 kV.
The intention is to check the correspondence of the actual voltage with the indicated value on the control panel of the X-ray unit. It is intended to measure the maximum energy only and not the complete X-ray spectrum.
The procedure is applicable for tank type and constant potential X-ray units.

ISO 14096-1:2005 specifies procedures for the evaluation of basic performance parameters of the radiographic film digitisation process such as spatial resolution and spatial linearity, density range, density contrast sensitivity and characteristic transfer curve. They can be integrated into the system software and together with a standard reference film used for quality control of the digitisation process. This reference film provides a series of test targets for performance evaluation. The test targets are suitable for evaluating a digitisation system with a spatial resolution down to 25 micrometres, a density contrast sensitivity down to 0,02 optical density, a density range of 0,5 to 4,5 and a film size capacity of (350 x 430) mm2. This standard does not address signal processing and display of the digitised data.

ISO 15708-2:2017 specifies the general principles of X-ray computed tomography (CT), the equipment used and basic considerations of sample, materials and geometry.
It is applicable to industrial imaging (i.e. non-medical applications) and gives a consistent set of CT performance parameter definitions, including how those performance parameters relate to CT system specifications.
ISO 15708-2:2017 deals with computed axial tomography and excludes other types of tomography such as translational tomography and tomosynthesis.

ISO 15708-3:2017 presents an outline of the operation of a computed tomography (CT) system and the interpretation of results with the aim of providing the operator with technical information to enable the selection of suitable parameters.
It is applicable to industrial imaging (i.e. non-medical applications) and gives a consistent set of CT performance parameter definitions, including how those performance parameters relate to CT system specifications.
ISO 15708-3:2017 deals with computed axial tomography and excludes other types of tomography such as translational tomography and tomosynthesis.

ISO 15708-4:2017 specifies guidelines for the qualification of the performance of a CT system with respect to various inspection tasks.
It is applicable to industrial imaging (i.e. non-medical applications) and gives a consistent set of CT performance parameter definitions, including how those performance parameters relate to CT system specifications.
ISO 15708-4:2017 deals with computed axial tomography and excludes other types of tomography such as translational tomography and tomosynthesis.

This document specifies fundamental techniques of film and digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on generally recognized practice and fundamental theory of the subject.
This document applies to the radiographic examination of steel pipes for service induced flaws such as corrosion pitting, generalized corrosion and erosion. Besides its conventional meaning, "pipe" as used in this document is understood to cover other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels.
Weld inspection for typical welding process induced flaws is not covered, but weld inspection is included for corrosion/erosion type flaws.
The pipes can be insulated or not, and can be assessed where loss of material due, for example, to corrosion or erosion is suspected either internally or externally.
This document covers the tangential inspection technique for detection and through-wall sizing of wall loss, including with the source:
a)    on the pipe centre line; and
b)    offset from pipe centre line by the pipe radius.
ISO 20769-2 covers double wall radiography, and note that the double wall double image technique is often combined with tangential radiography with the source on the pipe centre line.
This document applies to tangential radiographic inspection using industrial radiographic film techniques, computed radiography (CR) and digital detector arrays (DDA).

This document specifies fundamental techniques of film and digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on generally recognized practice and fundamental theory of the subject.
This document applies to the radiographic examination of pipes in metallic materials for service induced flaws such as corrosion pitting, generalized corrosion and erosion. Besides its conventional meaning, "pipe" as used in this document is understood to cover other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels.
Weld inspection for typical welding process induced flaws is not covered, but weld inspection is included for corrosion/erosion type flaws.
The pipes can be insulated or not, and can be assessed where loss of material due, for example, to corrosion or erosion is suspected either internally or externally.
This document covers double wall inspection techniques for detection of wall loss, including double wall single image (DWSI) and double wall double image (DWDI).
Note that the DWDI technique described in this document is often combined with the tangential technique covered in ISO 20769-1.
This document applies to in-service double wall radiographic inspection using industrial radiographic film techniques, computed digital radiography (CR) and digital detector arrays (DDA).

This document specifies the determination of the size of gamma radiographic sources of 0,5 mm or greater, made from the radionuclides Iridium 192, Ytterbium 169, Selenium 75 or Cobalt 60, by a method of radiography with X-rays. The source size of a gamma radiography source is an important factor which affects the image quality of gamma ray images.
The source size is determined with an accuracy of ± 10 % but typically not better than ± 0,1 mm.
The source size is provided by the manufacturer as the mechanical dimension of the source insert. A measurement may be required if the manufacturing process is validated or monitored after implementation of the source into the holder.
This document can be used for other radionuclides after validation.
The standard test method ASTM E1114 provides further information on the measurement of the Ir-192 source size, the characterization of the source shape, and its correct assembly and packaging.

This document specifies a method of determining the total image unsharpness and basic spatial resolution of radiographs and radioscopic images. The IQI with up to 13 wire pairs can be used effectively with tube voltages up to 600 kV. The IQI with more than 13 wire pairs can be used effectively at tube voltages lower than 225 kV. When using source voltages in the megavolt range, it is possible that the results are not be completely satisfactory.

This document specifies a procedure for the control of film processing systems.

ISO 16371-2:2017 specifies fundamental techniques of computed radiography with the aim of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on the fundamental theory of the subject and tests measurements. ISO 16371-2:2017 specifies the general rules for industrial computed X-rays and gamma radiography for flaw detection purposes, using storage phosphor imaging plates (IP). It is based on the general principles for radiographic examination of metallic materials on the basis of films, as specified in ISO 5579. The basic set-up of radiation source, detector and the corresponding geometry are intended to be applied in accordance with ISO 5579 and corresponding product standards such as ISO 17636 for welding and EN 12681 for foundry.
ISO 16371-2:2017 does not lay down acceptance criteria of the imperfections. Computed radiography (CR) systems provide a digital grey value image which can be viewed and evaluated on basis of a computer only. This practice describes the recommended procedure for detector selection and radiographic practice. Selection of computer, software, monitor, printer and viewing conditions are important but not the main focus of ISO 16371-2:2017.
The procedure it specifies provides the minimum requirements and practice to permit the exposure and acquisition of digital radiographs with a sensitivity of imperfection detection equivalent to film radiography and as specified in ISO 5579. Some application standards, e.g. EN 16407, can require different and less stringent practice conditions.

ISO 5579:2013 outlines the general rules for industrial X- and gamma-radiography for flaw-detection purposes, using film techniques, applicable to the inspection of metallic products and materials.
It does not lay down acceptance criteria of the imperfections.

ISO 19232-3:2013 specifies the minimum image quality values to ensure a uniform radiographic quality. It applies to the two types of image quality indicator as detailed in ISO 19232-1 for wire-type IQI and ISO 19232-2 for step/hole-type IQI and for the two techniques described in ISO 5579. Values are specified for the two classes of radiographic technique specified in ISO 5579.

ISO 19232-4:2013 gives instructions for the determination of image quality values and image quality tables.
If the IQI requirements specified in ISO 19232‑3 cannot be used because, for example, the absorption coefficients of the IQI material and the inspected material differ by more than 30 %, test exposures are necessary to determine acceptance of image quality values. The image quality values achieved by the test exposures are required for all exposures made under the same radiographic conditions.

ISO 19232-1:2013 specifies a device and a method for the determination of the image quality of radiographs using wire-type image quality indicators.

ISO 19232-2:2013 specifies a device and a method for the determination of the image quality of radiographs using step/hole-type image quality indicators.

The purpose of ISO 11699-1:2008 is to establish the performance of film systems.
ISO 11699-1:2008 is applicable for the classification of film systems in combination with specified lead screens for industrial radiography (non-destructive testing). ISO 11699-1:2008 is intended to ensure that the image quality of radiographs – as far as this is influenced by the film system – is in conformity with the requirements of International Standards such as ISO 5579, ISO 17636 and EN 12681.
ISO 11699-1:2008 does not apply to the classification of films used with fluorescent intensifying screens. The measurement of film systems in ISO 11699-1:2008 is restricted to a selected radiation quality to simplify the procedure. The properties of films will change with radiation energy, but not the ranking of film system quality.
Additional methods for evaluating the photographic process are described in ISO 11699-2, by which the performance of film systems can be controlled under the conditions given in industry.

This European standard specifies fundamental parameters of computed radiography systems with the aim of enabling satisfactory and repeatable results to be obtained economically. The techniques are based both on fundamental theory and test measurements. This European standard specifies the performance of computed radiography (CR) systems and the measurement of the corresponding parameters for the system scanner and phosphor imaging plate (IP). It describes the classification of these systems in combination with specified metal screens for industrial radiography. It is intended to ensure that the quality of images - as far as this is influenced by the scanner-IP system - is in conformity with the requirements of Part 2 of this standard. The standard relates to the requirements of film radiography defined in EN 584-1 and ISO 11699-1.
This European standard defines system tests at different levels. More complicated tests are described, which allow the determination of exact system parameters. They can be used to classify the systems of different suppliers and make them comparable for users. These tests are specified as manufacturer tests. Some of them require special tools, which are usually not available in user laboratories. Therefore, simpler user tests are also described, which are designed for a fast test of the quality of CR systems and long term stability.
There are several factors affecting the quality of a CR image including geometrical unsharpness, signal/noise ratio, scatter and contrast sensitivity. There are several additional factors (e.g. scanning parameters), which affect the accurate reading of images on exposed IPs using an optical scanner.

This European Standard specifies general rules for industrial X- and gamma-radioscopy for flaw detection purposes,
using radioscopic techniques, applicable to the testing of metallic materials.
It does not lay down acceptance criteria of the discontinuities.

This European Standard specifies a method for the measurement of focal spot dimensions within the range of 5 um to 300 um of X-ray systems up to and including 225 kV tube voltage, by means of radiographs of sharp edges. The image quality and the resolution of X-ray images highly depend on the characteristics of the focal spot. The imaging qualities of the focal spot are based on the two dimensional intensity distribution in the object plane. For certification purposes the radiographic technique is used.

This European Standard specifies a method for the measurement of focal spot dimensions above 0,1 mm of X-ray systems up to and including 500 kV tube voltage by means of the slit camera radiographic method. The voltage applied for this measurement is restricted to 200 kV. The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot, in particular the size and the two-dimensional intensity distribution in the object plane.

This European standard specifies the checking of focal spot dimensions above 0,5 mm of X-ray systems up to and including 500 kV tube voltage, by means of radiographs of sharp edges. The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot. The imaging qualities of a focal spot are based on the two dimensional intensity distribution in the object plane.

This European standard specifies the measurement of focal spot dimensions of industrial X-ray systems up to and including 500 kV tube voltage. It describes a method of direct mechanical scanning of focal spots above 0,1 mm with a highly collimated receiver. The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot, in particular the size and the two-dimensional intensity distribution.

The procedures given in this standard can be applied to all radioscopic systems which provide an electronic signal to a display unit or an automated image interpretation system. The radioscopic system is analysed for the response to well defined test specimen. The measurement should be performed by a sufficiently equipped and experienced laboratory. From the results, the specifications of the imaging system regarding image properties can be derived. This standard so far does not include imaging properties under moving conditions.

This part of the standard gives guidance on the on site control of equipment for radioscopy where the image is presented on a display unit including image processing. The radiation sources used can be X-rays or gamma rays. This standard establishes rules for testing a radioscopic system to assure a constant level of inspection quality. The tests should be easily performable by the operators of the system. They are based on an input signal from defined image quality indicators. The measurement of the systems response should be performed with the same equipment which is in use in this particular installation.

This European standard defines terms used in industrial radiographic testing.

This document specifies a method for the measurement of focal spot dimensions within the range of 5 µm to 300 µm of X-ray systems up to and including 225 kV tube voltage. This determination is based on the evaluation of an image with a dedicated focal spot that has been radiographically recorded using an edge and evaluated with a digital method.
The imaging quality and the resolution of X-ray images depend highly on the characteristics of the effective focal spot, in particular the size and the two-dimensional intensity distribution as seen from the detector plane.
For the characterisation of commercial X-ray tube types (i.e. for advertising or trade) the specific maximum values of annex A should be preferred.

ISO 15708-1:2017 gives the definitions of terms used in the field of computed tomography (CT). It presents a terminology that is not only CT-specific but which also includes other more generic terms and definitions spanning imaging and radiography. Some of the definitions represent discussion points aimed at refocusing their terms in the specific context of computed tomography.

This European Standard specifies a method for the measurement of focal spot dimensions above 0,2 mm of X-ray systems up to and including 500 kV tube voltage by means of the pinhole camera radiographic method. The voltage applied for this measurement is restricted to 200 kV for visual film evaluation.
The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot, in particular the size and the two dimensional intensity distribution.
For the characterisation of commercial X-ray tube types (i.e. for advertising or trade) the specific values of Table A.1 are used.

This European Standard specifies procedures for the evaluation of basic performance parameters of the radiographic film digitisation process such as spatial resolution and spatial linearity, density range, density contrast sensitivity and characteristic transfer curve. They can be integrated into the system software and together with a standard reference film (as described in clause 5) used for quality control of the digitisation process. This reference film provides a series of test targets for performance evaluation. The test targets are suitable for evaluating a digitisation system with a spatial resolution down to 25 µm, a density contrast sensitivity down to 0,02 optical density, a density range of 0,5 to 4,5 and a film size capacity of (350 x 430) mm². This standard does not address signal processing and display of the digitised data.

This European Standard specifies three film-digitisation quality classes for the requirements of non-destructive testing. The selected class depends on the radiation energy, penetrated material thickness and the quality level of the original radiographic film. This European Standard does not address signal processing, display and storage of the digitised data.

This standard specifies a constancy check of a X-ray system where mainly the X-ray voltage is checked and also the tube current and the constitution of the target which can be changing due to ageing of the tube. The thick filter method is based on a measurement of the dose rate behind a defined thick filter using defined distances between the X-ray tube, the filter and the measuring device. This method is very sensitive to changes of the voltage, but it does not provide an absolute value for the X-ray tube voltage.

This European standard specifies a method for the direct and absolute measurement of the average high voltage of constant potential (DC) X-ray systems on the secondary side of the high voltage generator. The intention is to check the correspondence with the indicated high voltage value on the control unit of the X-ray system. This method is applied to assure a reproducible operation of X-ray systems because the voltage influences particularly the penetration of materials and the contrast of X-ray images and also the requirements concerning the radiation protection.

This standard specifies the test method for a non-invasive measurement of X-ray tube voltages using the energy spectrum of X-rays (spectrometric method). It covers the voltage range from 10 kV to 500 kV. The intention is to check the correspondence of the actual voltage with the indicated value on the control panel of the X-ray unit. It is intended to measure the maximum energy only and not the complete X-ray spectrum. The procedure is applicable for tank type and constant potential X-ray units.

This European Standard specifies fundamental techniques of film and digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on generally recognized practice and fundamental theory of the subject.
This European Standard applies to the radiographic examination of pipes in metallic materials for service induced flaws such as corrosion pitting, generalized corrosion and erosion. Besides its conventional meaning, "pipe" as used in this standard should be understood to cover other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels.
Weld inspection for typical welding process induced flaws is not covered, but weld inspection is included for corrosion/erosion type flaws.
The pipes may be insulated or not, and can be assessed where loss of material due, for example, to corrosion or erosion is suspected either internally or externally.
This part of EN 16407 covers double wall inspection techniques for detection of wall loss, including double wall single image (DWSI) and double wall double image (DWDI).
Note that the DWDI technique described in this part of EN 16407 is often combined with the tangential technique covered in EN 16407-1.
This European Standard applies to in-service double wall radiographic inspection using industrial radiographic film techniques, computed digital radiography (CR) and digital detector arrays (DDA).

This European Standard specifies fundamental techniques of film and digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on generally recognized practice and fundamental theory of the subject.
This European Standard applies to the radiographic examination of pipes in metallic materials for service induced flaws such as corrosion pitting, generalized corrosion and erosion. Besides its conventional meaning, “pipe” as used in this standard should be understood to cover other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels.
Weld inspection for typical welding process induced flaws is not covered, but weld inspection is included for corrosion/erosion type flaws.
The pipes may be insulated or not, and can be assessed where loss of material due, for example, to corrosion or erosion is suspected either internally or externally.
This part of EN 16407 covers the tangential inspection technique for detection and through-wall sizing of wall loss, including:
a)   with the source on the pipe centre line, and
b)   with the source offset from it by the pipe radius.
Part 2 of EN 16407 covers double wall radiography, and note that the double wall double image technique is often combined with tangential radiography with the source on the pipe centre line.
This European Standard applies to tangential radiographic inspection using industrial radiographic film techniques, computed digital radiography (CR) and digital detector arrays (DDA).

This standard specifies the determination of the size of gamma radiographic sources of 0,5 mm or greater, made from the radionuclides Iridium 192, Ytterbium 169, Selenium 75 or Cobalt 60, by a method of radiography with X-rays. The source size of a gamma radiography source is an important factor which affects the image quality of gamma ray images. The source size is determined with an accuracy of +/- 10 % or 0,1 mm. This standard can be used for other radionuclides after validation.

ISO 19232-5:2013 specifies a method of determining the total image unsharpness of radiographs and real-time radioscopic systems.

This document describes a procedure for the control of film processing systems.

This European Standard specifies fundamental techniques of computed radiography with the aim of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on the fundamental theory of the subject and tests measurements. This European standard specifies the general rules for industrial computed X- and gamma radiography for flaw detection purposes, using phosphor imaging plates (IP). It is based on the general principles for radiographic examination of metallic materials on the basis of films (EN 444 and ISO 5579). The basic set-up of radiation source, detector and the corresponding geometry shall be applied in agreement with EN 444 and ISO 5579 and the corresponding product standards as e.g. EN 1435 for welding and EN 12681 for foundry. It does not lay down acceptance criteria of the imperfections.

This European Standard outlines the general rules for industrial X- and gamma radiography for flaw detection purposes, using film techniques, applicable to the inspection of metallic materials.   The examination shall be carried out by competent personnel qualified and certified according to EN 473 where applicable.   It does not lay down acceptance criteria of the imperfections.

This standard specifies the minimum image quality values to ensure a uniform radiographic quality. It applies to the two types of image quality indicator as detailed in EN 462-1 for wire type IQI and EN 462-2 for step/hole type IQI and for the two techniques described in EN 444. Values are specified for the two classes of radiographic technique specified in EN 444 and for ferrous metals.

This standard specifies a method of determining the total image unsharpness of radiographs and real-time radioscopic systems.

This standard gives instructions for the determination of image quality values and image quality tables. If the IQI requirements from part 3 of this standard cannot be used, because, for example, the absorption coefficients of the IQI material and the inspected material differ by more than 30 %, test exposures arenecessary to determine acceptance of image quality values. The image quality values achieved by the test exposures are required for all exposures made under the same radiographic conditions.

This part 2 of the standard specifies a device and a method for the determination of the image quality of radiographs. Other devices are the subject of parts 1 and 5 of the standard.