EN 12543-2:2021

SLOVENSKI STANDARD
01-junij-2021
Nadomešča:
SIST EN 12543-2:2009
Neporušitvene preiskave - Značilnosti goriščne površine v industrijskih
rentgenskih sistemih za neporušitveno preskušanje - 2. del: Metoda s kamero z
luknjico
Non-destructive testing - Characteristics of focal spots in industrial X-ray systems for use
in non-destructive testing - Part 2: Pinhole camera radiographic method
Zerstörungsfreie Prüfung - Charakterisierung von Brennflecken in Industrie-
Röntgenanlagen für die zerstörungsfreie Prüfung - Teil 2: Radiographisches
Lochkamera-Verfahren
Essais non destructifs - Caractéristiques des foyers émissifs des tubes radiogènes
industriels utilisés dans les essais non destructifs - Partie 2 : Méthode radiographique
par sténopé
Ta slovenski standard je istoveten z: EN 12543-2:2021
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12543-2
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2021
EUROPÄISCHE NORM
ICS 19.100 Supersedes EN 12543-2:2008
English Version
Non-destructive testing - Characteristics of focal spots in
industrial X-ray systems for use in non-destructive testing
- Part 2: Pinhole camera radiographic method
Essais non destructifs - Caractéristiques des foyers Zerstörungsfreie Prüfung - Charakterisierung von
émissifs des tubes radiogènes industriels utilisés dans Brennflecken in Industrie-Röntgenanlagen für die
les essais non destructifs - Partie 2 : Méthode zerstörungsfreie Prüfung - Teil 2: Radiographisches
radiographique par sténopé Lochkamera-Verfahren
This European Standard was approved by CEN on 1 March 2021.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12543-2:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test equipment . 6
4.1 Essential characteristics of the pinhole . 6
4.2 Alignment and position of the pinhole camera . 7
4.3 Position of the radiographic image detector . 8
4.4 Requirements on the radiographic image detector . 9
4.5 Image processing equipment for digital images. 10
4.6 Loading factors . 10
5 Measurement and determination of the focal spot size . 10
5.1 Measurement procedure . 10
5.2 Measurement with digital technique (preferred method) . 12
5.3 Evaluation with digital technique using Integrated Line Profiles (ILP) . 12
5.4 Measurement of effective focal spot size visually using film radiographs . 15
6 Classification and result of focal spot size measurement . 15
Annex A (normative) Values for the classification of X-ray tube focal spot sizes . 17
Bibliography . 19

European foreword
This document (EN 12543-2:2021) 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 October 2021, and conflicting national standards shall
be withdrawn at the latest by October 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12543-2:2008.
The main changes compared to the previous edition are as follows:
— The document has been technically and editorially revised;
— The scope of application was extended up to 1000 kV for digital detectors;
— Table 1 has been extended to include pin holes of 10 micron diameter;
— In Annex A, Focal Spot Classes have been introduced for simple X-ray tube classification;
— Chapter 5 introduces a new measurement procedure “Integrated Line Profile”;
— Table A.1 and Table A2 provide a new classification and result of focal spot measurement.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Introduction
In order to cover the large range of effective focal spot sizes, different methods are described in
EN 12543-1, EN 12543-2, EN 12543-3, EN 12543-4 and EN 12543-5.
The pinhole method (EN 12543-2) is intended for effective focal spot sizes above 0,1 mm and mainly
used for sealed standard and mini focus tubes.
The edge method of EN 12543-4 is intended for field applications when the users have to observe the
effective focal spot on a regular basis and the pinhole method is non-practical.
The edge measurement method of EN 12543-5 is intended for measurement of effective focal spot sizes
between 5 µm and 300 µm and mainly for the use with µ-Focus tubes (up to 100 µm) and mini focus
tubes with spot sizes of 100 µm to 300 µm.
In the overlapping ranges, the different standard parts provide comparable values within ± 20 %
tolerance.
ASTM E1165 describes the same pinhole procedure.
1 Scope
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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 19232-5, Non-destructive testing - Image quality of radiographs - Part 5: Determination of the
image unsharpness and basic spatial resolution value using duplex wire-type image quality indicators
(ISO 19232-5)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
actual focal spot
X-ray emitting area of the anode as viewed from a position perpendicular to the anode surface
Note 1 to entry: The actual focal spot is also called thermal focal spot in other literature.
Note 2 to entry: See Figure 3, Key 7.
3.2
effective focal spot
X-rays emitting area of the anode as viewed from the image plane of the detector
Note 1 to entry: The effective focal spot is also called optical focal spot in other literature.
Note 2 to entry: See Figure 3, Key 4.
3.3
effective focal spot size
focal spot size measured in accordance with this document
3.4
nominal focal spot size
SS
characteristic value for X-ray tubes having measured spot sizes within a defined range
Note 1 to entry: Annex A, Table A.1, defines the ranges of measured spot sizes in reference to the nominal value SS
for characterization of X-ray tubes.
3.5
Focal spot class
FS
number used to classify X-ray tubes based on the nominal focal spot size
3.6
basic spatial resolution of a detector
detector
SR
b
smallest degree of visible detail within a digital image, determined with the duplex wire image quality
indicator (IQI) according to EN ISO 19232-5 located on the detector (magnification = 1), from the
smallest number of the duplex wire pair with less than 20% modulation depth in a linearized profile
and it corresponds to ½ of the detector unsharpness
4 Test equipment
4.1 Essential characteristics of the pinhole
The pinhole camera shall consist of a diaphragm with a pinhole having following essential dimensions P
and H according to Table 1 dependent from the effective focal spot size.
Table 1 — Dimensions of the pinhole
Focal spot size Diameter P Height H
mm µm µm
0,1 to 0,3 10 ± 5 20 ± 5
> 0,3 to 1,0 30 ± 5 75 ± 10
> 1,0 100 ± 5 500 ± 10
The essential dimensions P and H are shown in Figure 1.
Dimensions in millimetres
Key
1 focal spot
Figure 1 — Essential dimensions of a pinhole diaphragm
The pinhole diaphragm shall be made of tungsten or of a similar absorbent material (e.g. gold, platinum,
tantalum or related alloys).
4.2 Alignment and position of the pinhole camera
The angle between the beam direction and the pinhole axis (see Figure 2) shall be smaller than ± 1,5 °.
When deviating from Figure 2, the direction of the beam shall be indicated.

Key
1 focal spot
2 beam direction
3 maximum deviation of the axis of the pinhole
Figure 2 — Alignment of the pinhole camera
The incident face of the pinhole diaphragm shall be placed at a distance m from the focal spot so that
the variation of the magnification over the extension of the actual focal spot does not exceed ± 5 % in
the beam direction. In no case shall this distance be less than 100 mm.
4.3 Position of the radiographic image detector
The radiographic image detector [film, imaging plate (CR) or digital detector array (DDA)] shall be
placed normal to the beam direction at a distance n from the incident face of the pinhole diaphragm
determined from the applicable magnification according to Figure 3 and Table 2.

Key
1 plane of anode
2 reference plane
3 radiographic image detector
4 magnified length of the effective focal spot
5 beam direction
6 incident face of the diaphragm
7 physical length of the actual focal spot
n distance from pin hole to detector
m distance from focal spot centre to pin hole
Figure 3 — Beam direction dimensions and planes
Table 2 — Magnification for focal spot pinhole images
Distance between Distance between
Anticipated Focal Spot Minimum
Focal Spot and Pinhole and
Size d Magnification n/m
Pinhole m Detector n
a a
mm
m m
0,1 to 1,0 5: 1 0,10 0,50
1,0 to 2,0 3: 1 0,25 0,75
> 2,0 1: 1 0,5 0,5
a
When using a technique that entails the use of enlargement factors and a 1 m focal spot to detector
distance (FDD = m+n) is not possible (see 5.1), the distance between the focal spot and the pinhole (m)
shall be adjusted to suit the actual focal spot to detector distance (FDD) used (for example, if a 600 mm
FDD is used, m shall be 100 mm for 5:1 enlargement, 150 mm for 3:1 enlargement, 300 mm for 1:1
enlargement, and the like).
4.4 Requirements on the radiographic image detector
Digital radiographic image detectors can be used instead of film, provided sensitivity, dy
...