SIST EN 61267:2006

SLOVENSKI SIST EN 61267:2006
STANDARD
junij 2006
Medicinska diagnostična rentgenska oprema - Sevalni pogoji pri ugotavljanju
karakteristik (IEC 61267:2005)
Medical diagnostic X-ray equipment - Radiation conditions for use in the
determination of characteristics (IEC 61267:2005)
ICS 11.040.50 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD
EN 61267
NORME EUROPÉENNE
January 2006
EUROPÄISCHE NORM
ICS 11.040.50 Supersedes EN 61267:1994

English version
Medical diagnostic X-ray equipment –
Radiation conditions for use in the determination of characteristics
(IEC 61267:2005)
Equipement de diagnostic médical  Medizinische diagnostische
à rayonnement X – Röntgeneinrichtung –
Conditions de rayonnement Bestrahlungsbedingungen zur
pour utilisation dans la détermination Bestimmung von Kenngrößen
des caractéristiques (IEC 61267:2005)
(CEI 61267:2005)
This European Standard was approved by CENELEC on 2005-12-01. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees 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.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61267:2006 E
Foreword
The text of document 62C/391/FDIS, future edition 2 of IEC 61267, prepared by SC 62C, Equipment for
radiotherapy, nuclear medicine and radiation dosimetry, of IEC TC 62, Electrical equipment in medical
practice, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61267
on 2005-12-01.
This European Standard supersedes EN 61267:1994.
The main changes compared to EN 61267:1994 include:
a) introduction of “practical peak voltage” for measuring X-ray tube voltage;
b) introduction of a new procedure for establishing the radiation qualities;
c) inserting of an informative Annex B “Determination of the amount of additional filtration” and a
normative Annex C “Measurement of the practical peak voltage”;
d) revision of radiation qualities and radiation conditions;
e) addition of term definitions.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2006-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-12-01
This European Standard makes reference to International Standards. Where the International Standard
referred to has been endorsed as a European Standard or a home-grown European Standard exists, this
European Standard shall be applied instead. Pertinent information can be found on the CENELEC web
site.
In this standard, the following print types are used:
– requirements proper: roman type;
– test specifications: italic type;
– notes and explanatory matter: small roman type;
– TERMS USED THROUGHOUT THIS PARTICULAR STANDARD THAT ARE DEFINED IN CLAUSE 3, OR IN OTHER
STANDARDS: SMALL CAPITALS.
__________
Endorsement notice
The text of the International Standard IEC 61267:2005 was approved by CENELEC as a European
Standard without any modification.
__________
NORME CEI
INTERNATIONALE
IEC
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
2005-11
Equipement de diagnostic médical
à rayonnement X –
Conditions de rayonnement pour utilisation dans
la détermination des caractéristiques

Medical diagnostic X-ray equipment –
Radiation conditions for use in the
determination of characteristics

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МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

61267  IEC:2005 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9

1 Scope and object.13
2 Normative references .19
3 Terms and definitions .19
4 Common aspects − Adjustment procedures .23
5 RQR – RADIATION QUALITIES in RADIATION BEAMS emerging from the X-RAY SOURCE
ASSEMBLY.25
6 RQA – RADIATION QUALITIES based on a PHANTOM made up of an aluminium ADDED
FILTER.31
7 RQC – RADIATION QUALITIES based on copper ADDED FILTER .35
8 RQT – RADIATION QUALITIES based on copper ADDED FILTER .37
9 Standard RADIATION CONDITIONS RQN.41
10 Standard RADIATION CONDITIONS RQB.45
11 Standard RADIATION CONDITION RQR-M .47
12 Standard RADIATION CONDITION RQA-M.49
13 Standard RADIATION CONDITIONS RQN-M.51
14 Standard RADIATION CONDITION RQB-M.53

Annex A (informative) Rationale.69
Annex B (informative) Determination of the amount of additional filtration.71
ANNEX C (normative) Measurement of the PRACTICAL PEAK VOLTAGE .75
Annex D (informative) Overview of radiation qualities and radiation conditions .79

Bibliography.81

Index of defined terms .83

61267  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MEDICAL DIAGNOSTIC X-RAY EQUIPMENT –
RADIATION CONDITIONS FOR USE IN THE
DETERMINATION OF CHARACTERISTICS

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61267 has been prepared by subcommittee 62C: EQUIPMENT for
RADIOTHERAPY, nuclear medicine and RADIATION dosimetry, of IEC technical committee 62:
Electrical EQUIPMENT in medical practice.
This second edition cancels and replaces the first edition published in 1994. It constitutes a
technical revision. The main changes of the second edition of this standard include:
a) introduction of “practical peak voltage” for measuring X-ray tube voltage;
b) introduction of a new procedure for establishing the radiation qualities;
c) inserting of an informative Annex B “Determination of the amount of additional filtration”
and a normative Annex C “Measurement of the practical peak voltage”;
d) revision of radiation qualities and radiation conditions;
e) addition of term definitions.

61267  IEC:2005 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
62C/391/FDIS 62C/393/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this standard, the following print types are used:
– requirements proper: roman type;
– test specifications: italic type;
– notes and explanatory matter: small roman type;
– TERMS USED THROUGHOUT THIS PARTICULAR STANDARD THAT ARE DEFINED IN CLAUSE 3, OR IN
OTHER STANDARDS: SMALL CAPITALS.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61267  IEC:2005 – 9 –
INTRODUCTION
To establish characteristics, aspects or properties of ASSOCIATED EQUIPMENT or to have
available RADIATION BEAMS for physical and medical investigations, sets of well-defined
RADIATION CONDITIONS can offer an important tool in many situations.
From a regulation and standardization point of view there is a need:
− to have available well-defined RADIATION CONDITIONS that can be used internationally to
specify standards of operation of X-RAY EQUIPMENT;
− to provide a basis for the harmonization of existing national standards;
− to provide uniform sets of RADIATION CONDITIONS (a dictionary of RADIATION CONDITIONS) to
describe and judge the performance of X-RAY EQUIPMENT for the benefit of
MANUFACTURERS, USERS, PATIENTS and health protection authorities;
− to solve communication problems between MANUFACTURERS, USERS and regulatory
authorities, stemming from a lack of internationally accepted definitions and test methods.
From an application point of view, commonly accepted sets of RADIATION CONDITIONS would in
general find use in:
− QUALITY CONTROL tests by MANUFACTURERS;
− installation and ACCEPTANCE TESTS;
− calibration of test instrumentation;
− type approval tests (where required);
− inspection and tests by regulatory authorities and testing institutes;
− physical and medical studies in physical laboratories and medical facilities;
− determination of characteristics of ASSOCIATED EQUIPMENT.
Standard RADIATION CONDITIONS can benefit a number of potential users, such as:
MANUFACTURERS of X-RAY EQUIPMENT;
−
− MANUFACTURERS of X-ray test instrumentation;
− research laboratories;
− testing institutes;
− USERS;
− government regulatory authorities;
− service organizations;
− standardization organizations.
Some provisions and statements in the body of this International Standard require additional
information. Such information is presented in Annex A called "Rationale". An asterisk in the
left-hand margin of a clause or subclause indicates the presence of such additional
information.
61267  IEC:2005 – 11 –
In this standard the X-RAY TUBE VOLTAGE is measured as the PRACTICAL PEAK VOLTAGE. The
rationale behind using this quantity is given in Annex C. A description of how the quantity
PRACTICAL PEAK VOLTAGE is measured is given in Annex C.
In the development of this edition of this standard efforts were made to set up procedures that
give a high degree of equivalence of standard RADIATION QUALITIES realized on different X-ray
machines. In the first edition the RADIATION QUALITIES were established by adjusting, within
given limits the X-RAY TUBE VOLTAGE to such a value that the required HALF-VALUE LAYER was
achieved. Depending on the total INHERENT FILTRATION an X-RAY TUBE VOLTAGE had to be
selected which could differ from the nominal value by as much as ±5 %. If the INHERENT
FILTRATION of the X-RAY TUBE was relatively strong this could be compensated by choosing a
lower X-RAY TUBE VOLTAGe and vice versa. For the example of a radiation quality with a
nominal X-RAY TUBE VOLTAGE of 100 kV this procedure meant that the tube voltage could be
set as low as 95 kV for a moderately filtered RADIATION QUALITY and as high as 105 kV for a
heavily filtered X-RAY TUBE. These two RADIATION QUALITIES were considered to be equivalent
as long as they both had the required HALF-VALUE LAYER.
This solution was not considered to be an ideal one. However, due to the lack of a suitable
and agreed definition of what is usually termed peak voltage no alternative was available.
With the arrival of the PRACTICAL PEAK VOLTAGE the situation has changed: With this quantity it
is possible by means of an electrical measurement to set the tube voltage of the x-ray
generator in question with any arbitrary shape of the ripple to a value that a radiograph taken
with a tube connected to this generator has the same low level contrast as a radiograph taken
with the same x-ray tube connected to a true constant potential generator operating at the
'correct' voltage.
Given the possibility of setting the tube voltage of any generator to the 'correct' value,
irrespective of the shape of the ripple, it becomes difficult to justify the deliberate selection of
a 'wrong' tube voltage to compensate for a below or an above average filtration of the x-ray
tube. The procedure, by which the radiation qualities are realized in this second edition,
consists of setting the X-RAY TUBE VOLTAGE to the 'correct' value and determining the amount
of filtration needed to produce the required HALF-VALUE LAYER. The nature of this process
implies that there is a certain maximum total INHERENT FILTRATION beyond which a given X-RAY
TUBE may no longer be used to produce a given RADIATION QUALITY. This is not new in
principle, but it is clearly expressed in this edition. In order not to exclude what are
considered as standard X-RAY TUBES, the HALF-VALUE LAYERS of some of the RADIATION
QUALITIES have been increased. The new HALF-VALUE LAYERS have been chosen in such a way
that it is possible to establish all RADIATION QUALITIES in this standard with an X-RAY TUBE with
2,5 mm Al hardening-equivalent filtration and with ANODE ANGLES down to 9°.
The procedure to be followed according to this edition for producing the RADIATION QUALITIES
of the RQR series does require a certain amount of additional effort. This additional effort is
largely compensated when the more heavily filtered radiation qualities are realized. The great
advantage of the new method lies in a much higher degree of equivalence of a given
RADIATION QUALITY with X-RAY TUBES having different INHERENT FILTRATIONS.

61267  IEC:2005 – 13 –
MEDICAL DIAGNOSTIC X-RAY EQUIPMENT −
RADIATION CONDITIONS FOR USE IN THE
DETERMINATION OF CHARACTERISTICS

1 Scope and object
This International Standard applies to test procedures which, for the determination of
characteristics of systems or components of medical diagnostic X-RAY EQUIPMENT, require
well-defined RADIATION CONDITIONS.
Except for mammography, this standard does not apply to conditions where discontinuities in
radiation absorption of elements are deliberately used to modify properties of the RADIATION
BEAM (for example by rare earth filters).
RADIATION CONDITIONS as used for screen-film sensitometry are not covered in this standard.
NOTE Screen-film sensitometry is the subject of the ISO 9236 series.
This standard deals with methods for generating RADIATION BEAMS with RADIATION CONDITIONS
which can be used under test conditions typically found in test laboratories or in
manufacturing facilities for the determination of characteristics of medical diagnostic X-RAY
EQUIPMENT.
Examples of such RADIATION QUALITIES are RADIATION BEAMS emerging through the filtration
from the X-RAY SOURCE ASSEMBLY. RADIATION CONDITIONS represent the more general case,
where SCATTERED RADIATION emerges from an EXIT SURFACE of a PATIENT or a PHANTOM. This
requires a well defined geometrical arrangement.
The most complete specification of RADIATION FIELDS is given by the spectral distribution of the
photon fluence. Since the measurement of X-RAY SPECTRA is a demanding task, this standard
expresses RADIATION QUALITIES in terms of the X-RAY TUBE VOLTAGE, the first and second HALF-
VALUE LAYER. In the case of RADIATION CONDITIONS, specifications are performed additionally in
terms of PHANTOM properties and geometry.
The attempt to characterize a spectral distribution just by means of the X-RAY TUBE VOLTAGE,
the first and possibly the second HALF-VALUE LAYER is thus a compromise between the
mutually conflicting requirements of avoiding excessive efforts for establishing a RADIATION
QUALITY and of the complete absence of any ambiguity in the definition of a RADIATION
QUALITY. Due to differences in the design and the age of X-RAY TUBES in terms of anode angle,
anode roughening and INHERENT FILTRATION, two RADIATION QUALITIES produced at a given X-
RAY TUBE VOLTAGE having the same first HALF-VALUE LAYER can still have quite different
spectral distributions. Given the inherent ambiguity in the characterization of RADIATION
QUALITY, it is essential that further tolerances introduced by allowing certain ranges of values,
e.g. for X-RAY TUBE VOLTAGE and first HALF-VALUE LAYER, must be sufficiently small not to
jeopardise the underlying objective of this standard. This standard is to ensure that
measurements of the properties of medical diagnostic equipment should produce consistent
results if RADIATION QUALITIES or RADIATION CONDITIONS in compliance with this standard are
used.
61267  IEC:2005 – 15 –
To achieve this objective, certain degrees of freedom in the way in which a RADIATION
CONDITION could be established in the framework of the first edition of this standard have been
removed. The essential restriction introduced in this second edition is that the X-RAY TUBE
VOLTAGE is measured and set to its 'correct' value. The second step is to attempt to establish
the prescribed first HALF-VALUE LAYER by adding into the beam the necessary amount of
ADDITIONAL FILTRATION. If the INHERENT FILTRATION provided by the X-RAY TUBE alone is so
strong that the HALF-VALUE LAYER of the RADIATION BEAM emerging from the X-RAY TUBE
ASSEMBLY as such is larger than that to be established, the X-RAY TUBE ASSEMBLY used is not
suited for producing the desired RADIATION CONDITION. This may occur if the anode angle of
the X-RAY TUBE ASSEMBLY is too small and/or in the case of excessive anode roughening due
to tube ageing.
In the approach outlined in the two preceding paragraphs the X-RAY TUBE VOLTAGE plays a
decisive role. It is therefore essential that the ‘correct’ X-ray tube voltage is chosen
irrespective of the type of high voltage generator connected to the X-RAY TUBE. The way in
which this is realized in this standard is by measuring the X-RAY TUBE VOLTAGE in terms of the
PRACTICAL PEAK VOLTAGE. This quantity is a weighted mean of all values of the X-RAY TUBE
VOLTAGE occurring during an exposure. The weighting is done in such a way that identical
values of the PRACTICAL PEAK VOLTAGE give identical values of the low level contrast on a
radiograph irrespective of the waveform supplied by the generator.
Although the PRACTICAL PEAK VOLTAGE can be measured non-invasively, the level of
uncertainty required in this standard demands the use of invasive techniques. The design and
age of the X-RAY TUBE ASSEMBLY influence the result of non-invasive measurements. When
PRACTICAL PEAK VOLTAGE is measured invasively, tube design and age have no influence on
the result of such a measurement.
In the framework of what is physically feasible, differences in tube design and ageing are
taken into account by adding the appropriate amount of ADDITIONAL FILTRATION.
In Annex C further explanations with regard to the PRACTICAL PEAK VOLTAGE are given.
This standard describes both primary RADIATION QUALITIES, which to a good approximation are
free of SCATTERED RADIATION (RQR, RQA, RQC, RQT, RQR-M and RQA-M) and, for PATIENT
simulation, RADIATION CONDITIONS containing SCATTERED RADIATION (RQN, RQB, RQN-M and
RQB-M).
It is crucial to be aware that in the presence of SCATTERED RADIATION the characteristics of X-
radiation in terms of fractions of AIR KERMA associated with the PRIMARY RADIATION and the
SCATTERED RADIATION depend on the position and nature of any ADDED FILTER or PHANTOM. It is
therefore obvious that AIR KERMA measurements in such RADIATION BEAMS need careful
consideration.
Clauses 5 to 9 deal with RADIATION CONDITIONS which are essentially free of SCATTERED
RADIATION. Due to the spatial homogeneity of these RADIATION CONDITIONS, the APPLICATION
DISTANCE does not influence the RADIATION CONDITIONS to a significant extent. These RADIATION
CONDITIONS are called RADIATION QUALITIES.
RADIATION QUALITIES of the RADIATION BEAM emerging from the X-RAY
• Clause 5 deals with
SOURCE ASSEMBLY. Such RADIATION QUALITIES can be used for determining ATTENUATION
properties of ASSOCIATED EQUIPMENT.
• Clause 6 deals with RADIATION QUALITIES of the RADIATION BEAM emerging from an irradiated
object, that simulates a PATIENT under the conditions that:

61267  IEC:2005 – 17 –
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite
• Clauses 7 and 8 deal with RADIATION QUALITIES derived from those dealt with in Clause 6 in
view of special applications like automatic exposure and automatic brightness control
systems and computed tomographs. The radiation transmitted through the irradiated object
has properties similar to those of the radiation transmitted through a PATIENT under the
conditions that:
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite.
• Clauses 9 and 10 deal with RADIATION CONDITIONS where SCATTERED RADIATION is taken into
account. This is done either by limiting the amount of SCATTERED RADIATION by appropriate
means and/or providing specific additional information.
• Clause 9 deals with measuring arrangements primarily intended in combination with
RADIATION CONDITIONS RQB of Clause 10 to be used for those measurements where the
contribution of SCATTERED RADIATION to the detected signal is minimal and is known as
NARROW BEAM CONDITION.
• Clause 10 deals with RADIATION CONDITIONS to be used for measurements where the
contribution of SCATTERED RADIATION to the detected signal is significant and is known as
BROAD BEAM CONDITION.
For the RADIATION QUALITIES specified in Clauses 5 to 10 it is assumed that an X-RAY TUBE is
available with an anode angle of not less than about 9 degrees. For x-ray tubes with smaller
anode angles it may not be possible to realize some or all RADIATION QUALITIES of Clause 5. If
some or all RADIATION QUALITIES of the RQR series cannot be realized with a given X-RAY TUBE
due to a too strong INHERENT FILTRATION, some special provisions have been made to
establish nevertheless the more heavily filtered RADIATION QUALITIES in Clauses 6 to 10 which
are in principle based on the RADIATION QUALITIES of the RQR series.
In order to make allowance for the use of X-RAY TUBES with ANODE ANGLES down to 9°, the
HALF-VALUE LAYERS of RADIATION QUALITIES RQR 4 to RQR 10 have been increased with
respect to the values specified in the first edition of this standard (1994).
Clauses 11 to 14 deal with RADIATION CONDITIONS applicable to mammography.
• Clause 11 deals with RADIATION QUALITIES of the RADIATION BEAM emerging from the X-RAY
SOURCE ASSEMBLY. Such RADIATION QUALITIES can be used for determining ATTENUATION
properties of ASSOCIATED EQUIPMENT.
• Clause 12 deals with RADIATION QUALITIES transmitted through an irradiated object, that
simulates a PATIENT under the conditions that:
– the contribution of SCATTERED RADIATION in the RADIATION BEAM is not significant;
– exact simulation of the spectral distribution of the RADIATION BEAM emerging from the
PATIENT is not a prerequisite.
• CLAUSE 13 deals with RADIATION CONDITIONS to be used for studies in mammography
under NARROW BEAM CONDITION. These RADIATION CONDITIONS are achieved by applying a
special tissue-equivalent PHANTOM.

61267  IEC:2005 – 19 –
• CLAUSE 14 deals with RADIATION CONDITIONS to be used for studies in mammography
under BROAD BEAM CONDITION. These RADIATION CONDITIONS are achieved by applying a
special tissue-equivalent PHANTOM.
The test instrumentation as required in this standard partly comprises SPECIFIC components or
a series of equivalent components out of which the most suitable should be chosen in order to
provide test conditions required to achieve prescribed test parameters. However, these
provisions in terms of hardware may not be available at USER facilities. As an example,
clinical mammography units are not suited for producing the RADIATION QUALITIES in Clauses
11 to 14 without modification. In order to adapt them the PATIENT SUPPORT needs to be
removed.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 61674:1997, Medical electrical equipment – Dosimeters with ionization chambers and/or
semi-conductor detectors as used in X-ray diagnostic imaging
IEC 61676:2002, Medical electrical equipment – Dosimetric instruments used for non-invasive
measurement of X-ray tube voltage in diagnostic radiology
ISO 4037-1:1996, X and gamma reference radiation for calibrating dosemeters and doserate
meters and for determining their response as a function of photon energy – Part 1: Radiation
characteristics and production methods
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61674 and
IEC 61676 (two of which have been repeated here for convenience) and the following
definitions apply.
3.1
APPLICATION DISTANCE
distance from the EFFECTIVE FOCAL SPOT to the APPLICATION PLANE
3.2
APPLICATION PLANE
plane perpendicular to the CENTRAL BEAM AXIS, where the standard RADIATION CONDITION is
defined
3.3
CENTRAL BEAM AXIS
line from the FOCAL SPOT through the centre of the DIAPHRAGM
3.4
EXIT SURFACE
plane or curved surface through which the RADIATION BEAM emerges from an
irradiated object
61267  IEC:2005 – 21 –
3.5
HALF-VALUE LAYER TEST DEVICE
device, normally shaped as foil or plate, which, when applied under NARROW BEAM CONDITIONS,
attenuates AIR KERMA RATE to one half of the value that is measured without the device
3.6
HOMOGENEITY COEFFICIENT
ratio of first to second HALF-VALUE LAYER
NOTE The first HVL gives the thickness of a SPECIFIED material which reduces the AIR KERMA RATE to half the
value without this material; the second HVL gives the additional thickness to reduce the AIR KERMA RATE to a
quarter.
3.7
PRACTICAL PEAK VOLTAGE
Û
w(U )U
∑ i i
ˆ i
weighted average of the X-RAY TUBE VOLTAGE according to , where U is the
U = i
w(U )
∑ i
i
sequence of measured X-RAY TUBE VOLTAGES in kV and the weighting function w(U ) given by
i
w(U ) = 0   for U < 20 kV and
i i
w(U ) = exp{a ⋅U + b ⋅U + c}       for 20 kV< U <36 kV and
i i i
i
4 3 2
w(U ) = d ⋅U + e ⋅U + f ⋅U + g ⋅U + h for 36 kV < U < 150 kV with
i i i
i i i
-3 -1 +1
a = −8,646855*10 , b = 8,170361*10 , c = −2,327793*10 and
-10 -7 -5 -5
d = 4,310644*10 , e = −1,662009*10 , f = 2,308190*10 , g = 1,030820*10 ,
-2
h = −1,747153*10
for applications other than mammography and

w(U ) = 0   for U < 20 kV and
i i
4 3 2
w(U ) = exp{k ⋅U + l ⋅U + m ⋅U + n ⋅U + o}      for 20 kV < U < 50 kV with
i i i
i i i
-6 -4 -2 -1
k = −2,142352*10 , l = 2,566291*10 , m = −1,968138*10 , n = 8,506836*10 ,
+1
o = −1,514362*10
for mammography
3.8
RADIATION CONDITION
description of RADIATION FIELDS by a set of electrical and geometrical parameters like X-RAY
TUBE VOLTAGE, TOTAL FILTRATION and geometrical arrangements
3.9
RADIATION QUALITY
radiation condition whereby the RADIATION FIELD includes only an insignificant amount of
SCATTERED RADIATION
NOTE This definition takes precedence over that given in IEC TR 60788.

61267  IEC:2005 – 23 –
3.10
REFERENCE POINT
point of a RADIATION DETECTOR which, during the calibration of the DETECTOR, is brought to
coincidence with the point at which the CONVENTIONAL TRUE VALUE is specified
[IEC 61674:1997, définition 3.17, modifiée]
3.11
X-RAY TUBE VOLTAGE
potential difference applied to an X-RAY TUBE between the anode and the cathode. The unit of
this quantity is the volt (V)
[IEC 61676:2002, definition 3.25 ]
NOTE The X-RAY TUBE VOLTAGE may vary as a function of time. The PRACTICAL PEAK VOLTAGE is a weighted value
of the X-RAY TUBE VOLTAGE over a time period.
3.12
REFERENCE DIRECTION
specified direction to which characteristics such as target angle, radiation field and
specifications with respect to the imaging quality of the radiation source are referenced
4 Common aspects − Adjustment procedures
4.1 Standard RADIATION CONDITIONS
The standard RADIATION CONDITIONS are characterized by a letter code.
They are described, as applicable, in terms of:
− the material of the emitting TARGET;
− the X-RAY TUBE VOLTAGE;
− a specific TOTAL FILTRATION consisting of that of
• the X-ray source assembly, and
• an added filter or phantom of specific material and thickness;
− the first half-value layer;
− homogeneity coefficient
− an application distance.
4.2 RADIATION DETECTOR
The RADIATION DETECTOR to be used for measurements of AIR KERMA or AIR KERMA RATE to
determine the attenuation curve shall comply with IEC 61674. Additionally,
– its energy dependence of response shall not exceed ±3 % over the range of radiation
qualities N15 to N200 of ISO 4037-1;
− the dimensions of the entrance surface of its SENSITIVE VOLUME shall be such that it will be
fully covered by the RADIATION BEAM;
− its sensitivity shall be such that measurements can (still) be carried out, when applying
ADDED FILTERS or PHANTOMS described in this standard;
− the RADIATION DETECTOR shall be applicable for the AIR KERMA RATES involved (with and
without application of ADDED FILTERS or PHANTOMS).

61267  IEC:2005 – 25 –
4.3 PERCENTAGE RIPPLE of the X-RAY TUBE VOLTAGE
PERCENTAGE RIPPLE of the X-RAY TUBE VOLTAGE shall not exceed 10 %, apart from the case of
mammography, where a limit of 4 % shall not be exceeded.
4.4 Anode material
Requiring tungsten as target material does not refer to pure tungsten but to a “tungsten-rich”
target material. For technological reasons, for example, alloys are used containing up to 10 %
of rhenium.
5 RQR – RADIATION QUALITIES in RADIATION BEAMS emerging from the X-RAY
SOURCE ASSEMBLY
5.1 Object
This clause deals with RADIATION QUALITIES, which are used for measurements in the
RADIATION BEAM as emerging from the X-RAY SOURCE ASSEMBLY. Such RADIATION QUALITIES are,
for example, applied for determining characteristics of PATIENT SUPPORTS in case the PATIENT
SUPPORT is situated in between the X-RAY SOURCE ASSEMBLY and the PATIENT.
5.2 Characterization
The standard RADIATION QUALITIES, characterized by the letter code given in the first column of
Table 1, are referred to as follows:
RQR x IEC 61267:200y,
where x is, according to Table 1, a number between 2 and 10, and y represents the year of
publication of the revision of this standard.
5.3 Description
The standard RADIATION QUALITIES RQR are described by the set of parameters given below:
− an emitting TARGET of tungsten;
− an X-RAY TUBE VOLTAGE adjusted to the values given in column 2 of Table 1;
− an adjusted TOTAL FILTRATION of the X-RAY SOURCE ASSEMBLY;
– the first HALF-VALUE LAYER as given in column 3 of Table 1.
– the HOMOGENEITY COEFFICIENT within ± 0,03 to that given in column 4 of Table 1
The method of production of RADIATION QUALITIES RQR according to the description specified
in this subclause is given in 5.4 and 5.6.

61267  IEC:2005 – 27 –
Table 1 − Characterization of standard RADIATION QUALITIES
RQR 2 to RQR 10
Standard RADIATION X-RAY TUBE VOLTAGE First HALF-VALUE LAYER HOMOGENEITY
QUALITY COEFFICIENT
in mm of aluminium
kV
RQR 2 40 1,42 0,81
RQR 3 50 1,78 0,76
RQR 4 60 2,19 0,74
RQR 5 70 2,58 0,71
RQR 6 80 3,01 0,69
RQR 7 90 3,48 0,68
RQR 8 100 3,97 0,68
RQR 9 120 5,00 0,68
RQR 10 150 6,57 0,72
5.4 X-RAY TUBE VOLTAGE adjustment
The X-RAY TUBE VOLTAGE shall be specified in terms of the PRACTICAL PEAK VOLTAGE. The X-
RAY TUBE VOLTAGE shall be set to the prescribed value with an uncertainty of 1,5 % or 1,5 kV
(coverage factor k = 2), whatever is larger.
5.5 ADDITIONAL FILTRATION
Using the setting of the X-RAY TUBE VOLTAGE determined in the previous subclause, an
ATTENUATION curve shall be measured with aluminium ATTENUATION layers. The ATTENUATION
curve shall cover at least an ATTENUATION of a factor 6.
For all cases except for those of mammography, the amount of ADDITIONAL FILTRATION required
in order to establish the first HALF-VALUE LAYER and to approximate the HOMOGENEITY
COEFFICIENT given in the appropriate tables shall be determined. If the first HALF-VALUE LAYER
of the X-RAY TUBE ASSEMBLY is larger than the value to be obtained, the X-RAY TUBE ASSEMBLY
shall not be used for establishing the desired RADIATION QUALITY.
An example of determining the amount of ADDITIONAL FILTRATION required is described in
Annex B.
Add the amount of ADDITIONAL FILTRATION as determined above. Verify the HALF-VALUE LAYER
with the modified filtration by means of the HALF-VALUE LAYER TEST DEVICE. The correct
standard RADIATION QUALITY is obtained, when the quotient of the measured values of AIR
KERMA or AIR KERMA RATE – obtained in measurements with and without the HALF-VALUE LAYER
TEST DEVICE in the RADIATION BEAM – is between 0,485 and 0,515.
NOTE Since the establishment of the correct HALF VALUE LAYER is a non-linear procedure, it may be necessary to
repeat the steps described in this subclause starting with the measurement of the ATTENUATION curve. Alternatively,
when the INDICATED VALUES of AIR KERMA or AIR KERMA RATE – obtained in measurements with and without the HALF-
VALUE LAYER TEST DEVICE in the RADIATION BEAM –are just marginally outside the range between 0,485 and 0,515
the added filtration may be varied by trial and error. If the ratio of the AIR KERMA is below 0,485, the ADDITIONAL
FILTRATION needs to be increased and vice versa. The ATTENUATION curve can be determined with a set of seven
Al-filters starting with a thickness of 0,5 mm, where the thickness increases by a factor of two from one filter to the
next until and including a filter thickness of 32 mm).

61267  IEC:2005 – 29 –
5.6 Test equipment
5.6.1 X-RAY TUBE VOLTAGE measuring device
The X-RAY TUBE VOLTAGE shall be measured with a voltage divider connected parallel to the
X-RAY GENERATOR and the X-RAY TUBE.
NOTE Non-invasive X-RAY TUBE VOLTAGE measuring devices are not appropriate for the purposes of this standard.
5.6.2 Auxiliary filter
Auxiliary filters of thin layers of aluminium shall be available and shall be suitable for
mounting on the X-RAY SOURCE ASSEMBLY to enable the first HALF-VALUE LAYER given in Table 1
to be obtained.
The material of these layers shall be aluminium of a purity of at least 99,9 %.
5.6.3 ATTENUATION layers
To produce the nominal HALF-VALUE LAYER, as required in 5.3 in order to achieve a standard
RADIATION QUALITY RQR, an ATTENUATION curve shall be measured by means of a series of
aluminium ATTENUATION layers. By combining the aluminium ATTENUATION layers it shall be
ATTENUATION layer thickness up to 25 mm in steps not larger than
possible to establish a total
0,5 mm. The thickness of each ATTENUATION layer shall be known to within ±0,01 mm.
The material of these ATTENUATION layers shall be aluminium of a purity of at least 99,9 %.
The size of the ATTENUATION layers shall be large enough to intercept the full RADIATION BEAM
intended to be used for the test (see Figure 1).
5.6.4 DIAPHRAGM
A DIAPHRAGM shall be available to limit the extent of the RADIATION BEAM immediately after the
EXIT SURFACE of the ATTENUATION layer to not more than 50 mm x 50 mm (see Figure 1).
5.6.5 RADIATION DETECTOR
See 4.2.
5.6.7 HALF-VALUE LAYER TEST DEVICES
To produce the nominal HALF-VALUE LAYER, as required in 6.3.1 in order to achieve a standard
RADIATION QUALITY RQR, a HALF-VALUE LAYER TEST DEVICE of aluminium shall be available. This
HALF-VALUE LAYER TEST DEVICE, consisting preferably of a single layer, shall have a thickness
equal to the nominal first HALF-VALUE LAYER given in the third column of Table 1 within a total
tolerance of ± 0,1 mm.
The material of these layers shall be aluminium of a purity of at least 99,9 %.
The size of the HALF-VALUE LAYER TEST DEVICE shall be large enough to intercept the full
RADIATION BEAM intended to be used for the test (see Figure 1).

61267  IEC:2005 – 31 –
5.7 Generation and verification of the standard RADIATION QUALITIES RQR
5.7.1 Geometry
The RADIATION DETECTOR shall be placed with its REFERENCE POINT on the REFERENCE AXIS in
the APPLICATION PLANE. The APPLICATION PLANE shall be at a distance from the FOCAL SPOT of
not less than 550 mm or not less than twice the distance between the FOCAL SPOT and the
HALF-VALUE LAYER TEST DEVICE, whichever is the larger.
To minimize backscatter effects, only those objects required for measurement purposes shall
be placed in the volume inside the RADIATION BEAM, which is limited by the APPLICATION PLANE
and the plane normal to the RADIATION BEAM AXIS containing a point 450 mm beyond the
APPLICATION PLANE in the REFERENCE DIRECTION (see Figure 1).
5.7.2 Establishing one standard RADIATION QUALITY RQR
The steps described in 5.4 shall be carried out using the parameters given in Table 1. As a
result of these measurements it may be necessary to modify the TOTAL FILTRATION by
mounting an auxiliary filter on the X-RAY SOURCE ASSEMBLY.
5.7.3 Establishing a series of RADIATION QUALITIES RQR
The amount of ADDITIONAL FILTRATION required for establishing each of the RADIATION QUALITIES
RQR will not be identical for each RADIATION QUALITY. If the difference between the largest and
smallest value of the ADDITIONAL FILTRATION is not larger than 0,5 mm, one single ADDED FILTER
with a thickness close to the arithmetic mean of all values of ADDITIONAL FILTRATION may be
used for establishing all RADIATION QUALITIES RQR with one single filter.
6 RQA – RADIATION QUALITIES based on a PHANTOM made up of an aluminium
ADDED
...