EN 14784-2:2005

SLOVENSKI STANDARD
01-november-2005
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Non-destructive testing - Industrial computed radiography with storage phosphor imaging
plates - Part 2: General principles for testing of metallic materials using X-rays and
gamma rays
Zerstörungsfreie Prüfung - Industrielle Computer-Radiographie mit Phosphor-
Speicherfolien - Teil 2: Grundlagen für die Prüfung von metallischen Werkstoffen mit
Röntgen- und Gammastrahlen
Essais non destructifs - Radiographie industrielle numérisée avec plaques-images au
phosphore - Partie 2 : Principes généraux de l'essai radiographique, a l'aide de rayons X
et gamma, des matériaux métalliques
Ta slovenski standard je istoveten z: EN 14784-2:2005
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 14784-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2005
ICS 19.100
English version
Non-destructive testing - Industrial computed radiography with
storage phosphor imaging plates - Part 2: General principles for
testing of metallic materials using X-rays and gamma rays
Essais non destructifs - Radiographie industrielle Zerstörungsfreie Prüfung - Industrielle Computer-
numérisée avec plaques-images au phosphore - Partie 2 : Radiographie mit Phosphor-Speicherfolien - Teil 2:
Principes généraux de l'essai radioscopique, à l'aide de Grundlagen für die Prüfung von metallischen Werkstoffen
rayons X et gamma, des matériaux métalliques mit Röntgen- und Gammastrahlen
This European Standard was approved by CEN on 1 July 2005.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14784-2:2005: E
worldwide for CEN national Members.

Contents
Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Terms and definitions .4
4 Personnel qualification .5
5 Classification of computed radiographic techniques.5
6 General.6
7 Recommended techniques for making computed radiographs .6
8 Test report .14
Bibliography .16

Foreword
This European Standard (EN 14784-2:2005) has been prepared by Technical Committee CEN/TC 138 “Non-
destructive testing”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical text or
by endorsement, at the latest by February 2006, and conflicting national standards shall be withdrawn at the latest
by February 2006.
EN 14784 comprises a series of European Standards for industrial computed radiography with storage phosphor
imaging plates which is made up of the following:
EN 14784-1 Non-destructive testing – Industrial computed radiography with storage phosphor imaging plates –
Part 1: Classification of systems
EN 14784-2 Non-destructive testing – Industrial computed radiography with storage phosphor imaging plates –
Part 2: General principles for testing of metallic materials using X-rays and gamma rays
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,
Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
1 Scope
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 document specifies the general rules for industrial computed X-
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 (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.
2 Normative references
The following referenced documents are indispensable for the application of this European Standard. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
EN 462-1, Non-destructive testing — Image quality of radiographs — Part 1: Image quality Indicators (wire type) —
Determination of image quality value.
EN 462-2, Non-destructive testing — Image quality of radiographs — Part 2: Image quality indicators (step/hole
type) — Determination of image quality value.
EN 462-3, Non-destructive testing — Image quality of radiographs — Part 3: Image quality classes for ferrous
metals.
EN 462-4, Non-destructive testing — Image quality of radiographs — Part 4: Experimental evaluation of image
quality values and image quality tables.
EN 462-5, Non-destructive testing — Image quality of radiographs — Part 5: Image quality indicators (duplex wire
type), determination of image unsharpness value.
EN 14784-1:2005; Non-destructive testing — Industrial computed radiography with storage phosphor imaging
plates — Part 1: Classification of systems.
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
storage phosphor imaging plate systems
complete system of a storage phosphor imaging plate (IP) and a corresponding read out unit (scanner or reader),
which converts the information of the IP into a digital image
3.2
nominal thickness
t
nominal thickness of the material in the region under examination. Manufacturing tolerances do not have to be
taken into account
3.3
penetrated thickness
w
thickness of material in the direction of the radiation beam calculated on basis of the nominal thickness.
For multiple wall techniques the penetrated thickness is calculated from the nominal thickness.
3.4
object-to-detector distance
b
distance between the radiation side of the test object and the detector surface measured along the central axis of
the radiation beam
3.5
source size
d
size of the source of radiation
3.6
source-to-detector distance (SDD)
distance between the source of radiation and the detector measured in the direction of the beam
3.7
source-to-object distance
f
distance between the source of radiation and the source side of the test object measured along the central axis of
the radiation beam
4 Personnel qualification
The examination should be carried out by qualified and capable personnel. In order to prove this qualification, it is
recommended to certify the personnel in accordance with EN 473 or ISO 9712.
5 Classification of computed radiographic techniques
Computed radiographic techniques are subdivided into two classes:
 Class A: basic technique;
 Class B: improved technique.
Class B technique will be used when class A may be insufficiently sensitive.
Better techniques, compared with class B, are possible and may be agreed between the contracting parties by
specification of all appropriate test parameters.
The choice of radiographic technique shall be agreed between the parties concerned.
Due to image parameters such as SNR, un-sharpness and sensitivity to scattered radiation and hardening
differences exist between film radiographs and computed radiographs.
Nevertheless, the perception of flaws using film radiography or computed radiography is comparable by using class
A and class B techniques, respectively. The perceptibility shall be proven by the use of IQIs according to EN 462-1,
EN 462-2 and EN 462-5.
If it is not possible for technical reasons to meet one of the conditions specified for the class B, such as the type of
radiation source or the source-to-object distance f, it may be agreed between the contracting parties that the
condition selected may be that specified for class A. The loss of sensitivity shall be compensated for, by doubling
the required minimum exposure time with the goal to increase the minimum SNR by a factor of 1.4 (additional to
the SNR required from the plate-scanner classes given by Tables 2 to 3). Because of the resulting improved
sensitivity compared to class A, the test sections may be regarded as examined within class B.
NOTE This applies only to those IP-scanner systems whose SNR is not limited by the in-homogeneity of the phosphor
layer or the scanner dynamic at the required minimum exposure time (see clause 7.9).
6 General
6.1 Protection against ionising radiation
WARNING — Exposure of any part of the human body to X-rays or gamma-rays can be highly injurious to
health. Wherever X-ray equipment or radioactive sources are in use, appropriate legal requirements must
be applied.
Local or national or international safety precautions when using ionizing radiation shall be strictly applied.
6.2 Surface preparation and stage of manufacture
In general, surface preparation is not necessary, but where surface imperfections or coatings might cause difficulty
in detecting defects, the surface shall be ground smooth or the coatings shall be removed.
Unless otherwise specified computed radiography shall be carried out after the final stage of manufacture, e.g. after
grinding or heat treatment.
6.3 Identification of radiographs
Symbols shall be affixed to each section of the object being radiographed. The images of these symbols shall
appear in the radiograph outside the region of interest where possible and shall ensure unequivocal identification of
the section.
6.4 Marking
Permanent markings on the object to be examined shall be made in order to locate accurately the position of each
radiograph.
Where the natures of the material and/or its service conditions do not permit permanent marking, the location may
be recorded by means of accurate sketches or photographs.
6.5 Overlap of phosphor imaging plates
When radiographing an area with two or more separate phosphor imaging plates (IP), the IPs shall overlap
sufficiently to ensure that the complete region of interest is radiographed. This shall be verified by a high-density
marker on the surface of the object that will appear on each image.
6.6 Image quality indicators
The quality of image shall be verified by use of IQIs, in accordance with the specific application of the following
European Standards - EN 462-1 for the contrast resolution and EN 462-5 for measurement of un-sharpness.
Therefore, two IQIs are always required on each image. The minimum IQI-values in dependence on wall thickness
and geometry are defined by EN 462-3. This document may be applied to non-ferrous metals if appropriate IQIs
are used. In specific application cases minimum IQI-values may be specified in accordance with EN 462-4. IQIs of
the step-hole type (e.g. EN 462 2) should not be applied because the wire IQIs are more suitable to encourage the
operator to compensate for limited sharpness with increased contrast. This compensation can be achieved either
by reduction of the source voltage or by longer exposure time to increase the SNR of the computed radiograph.
7 Recommended techniques for making computed radiographs
7.1 Test arrangements
Test arrangements shall be determined from the specific application standards for film radiography as e.g. EN 1435
and EN 12681.
7.
...