prEN ISO 32543-1

SLOVENSKI STANDARD
01-julij-2025
Neporušitvene preiskave - Značilnosti goriščne površine v industrijskih
rentgenskih sistemih - 2. del: Metoda s kamero z luknjico (ISO 32543-1:2024)
Non-destructive testing - Characteristics of focal spots in industrial X-ray systems - Part
1: Pinhole camera radiographic method (ISO 32543-1:2024)
Zerstörungsfreie Prüfung - Charakterisierung von Brennflecken in Industrie-
Röntgenanlagen - Teil 1: Radiographisches Lochkamera-Verfahren (ISO 32543-1:2024)
Essais non destructifs - Caractéristiques des foyers émissifs des tubes radiogènes
industriels - Partie 1: Méthode radiographique par sténopé (ISO 32543-1:2024)
Ta slovenski standard je istoveten z: prEN ISO 32543-1
ICS:
19.100 Neporušitveno preskušanje Non-destructive testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

International
Standard
ISO 32543-1
First edition
Non-destructive testing —
2024-05
Characteristics of focal spots in
industrial X-ray systems —
Part 1:
Pinhole camera radiographic method
Essais non destructifs — Caractéristiques des foyers émissifs des
tubes radiogènes industriels —
Partie 1: Méthode radiographique par sténopé
Reference number
ISO 32543-1:2024(en) © ISO 2024

ISO 32543-1:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
ISO 32543-1:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test equipment . 2
4.1 Essential characteristics of the pinhole .2
4.2 Alignment and position of the pinhole camera .3
4.3 Position of the radiographic image detector .4
4.4 Requirements on the radiographic image detector .5
4.5 Image processing equipment for digital images .5
4.6 Loading factors . .6
5 Measurement and determination of the focal spot size . 6
5.1 Measurement procedure .6
5.2 Measurement with digital technique (preferred method) .7
5.3 Evaluation with digital technique using integrated line profiles (ILP) .8
5.4 Measurement of effective focal spot size visually using film radiographs .10
6 Classification and result of focal spot size measurement .11
Annex A (normative) Values for the classification of X-ray tube focal spot sizes .13
Bibliography .15

iii
ISO 32543-1:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
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with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
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rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by the European Committee for Standardization (CEN) (EN 12543-2:2021) and
was adopted (without modification other than those given below) by Technical Committee(s) ISO/TC 135,
Non-destructive testing, Subcommittee SC 5, Radiographic testing.
The main changes are as follows:
— verbal forms in the Scope and 5.1 NOTE have been modified to meet ISO content requirements;
— definitions in Clause 3 have been modified to remove reference to content outside Clause 3;
— Figures 5, 6 and 7 have been updated;
— keys have been added to Figures 1, 2, 3, 4, 5 and 6;
— change "profile integration" to "profile averaging" when referring to the averaging of the profile lines;
— minor editorial corrections.
A list of all parts in the ISO 32543 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 32543-1:2024(en)
Introduction
In order to cover the large range of effective focal spot sizes, different methods are described in the
ISO 32543 series.
The pinhole method of ISO 32543-1 is intended for effective focal spot sizes above 0,1 mm and mainly used
for sealed standard and mini focus tubes. ASTM E1165 describes the same pinhole procedure.
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 parts of the EN 12543 series and ISO 32543 series provide comparable
values within ±20 % tolerance.

v
International Standard ISO 32543-1:2024(en)
Non-destructive testing — Characteristics of focal spots in
industrial X-ray systems —
Part 1:
Pinhole camera radiographic method
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 1 000 kV X-ray 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 can 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. Compared to the other methods specified in the EN 12543 series and the ISO 32543 series, this method
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), the specific FS (focal
spot) values of Annex A can be 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.
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
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
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.

ISO 32543-1:2024(en)
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.
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
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 the detector
detector
SR
b
smallest degree of visible detail within a digital image, determined with the duplex wire image quality
indicator (IQI) according to 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 followed 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.

ISO 32543-1:2024(en)
Dimensions in millimetres
Key
1 focal spot
P pinhole diameter
H pinhole height
Figure 1 — Essential dimensions of
...