SIST EN 60731:1998

SLOVENSKI STANDARD
SIST EN 60731:1998
01-september-1998
Medical electrical equipment - Dosimeters with ionization chambers as used in
radiotherapy (IEC 60731:1997)
Medical electrical equipment - Dosimeters with ionization chambers as used in
radiotherapy
Medizinische elektrische Geräte - Dosimeter mit Ionisationskammern zur Anwendung in
der Strahlentherapie
Appareils électromédicaux - Dosimètres à chambre d'ionisation utilisés en radiothérapie
Ta slovenski standard je istoveten z: EN 60731:1997
ICS:
11.040.50 Radiografska oprema Radiographic equipment
17.240 Merjenje sevanja Radiation measurements
SIST EN 60731:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60731:1998

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SIST EN 60731:1998

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SIST EN 60731:1998

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SIST EN 60731:1998

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SIST EN 60731:1998

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SIST EN 60731:1998
NORME
CEI
INTERNATIONALE
IEC
60731
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1997-07
Appareils électromédicaux –
Dosimètres à chambres d’ionisation
utilisés en radiothérapie
Medical electrical equipment –
Dosimeters with ionization chambers
as used in radiotherapy
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
XD
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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SIST EN 60731:1998
60731 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 11
INTRODUCTION . 13
Clause
1 Scope and object. 15
2 Normative references . 17
3 Terminology and definitions . 19
4 General requirements . 31
4.1 Performance requirements . 31
4.2 REFERENCE VALUES and STANDARD TEST VALUES . 31
4.3 General test conditions and methods . 33
4.3.1 STANDARD TEST CONDITIONS . 33
4.3.2 Test of components. 33
4.3.3 RATED or EFFECTIVE RANGE of DOSE (or KERMA) RATES. 33
4.3.4 Uncertainty of measurement . 35
4.3.5 Adjustments during test . 35
4.3.6 Test conditions particular to CHAMBER ASSEMBLIES. 35
4.3.7 Test conditions particular to MEASURING ASSEMBLIES. 35
4.3.8 Test conditions particular to STABILITY CHECK DEVICES . 37
4.3.9 Use of STABILITY CHECK DEVICES. 37
4.4 Summary tables . 37
Table 1 – REFERENCE CONDITIONS and STANDARD TEST CONDITIONS
1a – CHAMBER ASSEMBLY . 39
1b – MEASURING ASSEMBLY . 39
Table 2 – Limits of PERFORMANCE CHARACTERISTICS at STANDARD TEST CONDITIONS
2a – CHAMBER ASSEMBLY . 41
2b – MEASURING ASSEMBLY . 41
Table 3 – LIMITS OF VARIATION of PERFORMANCE CHARACTERISTICS for effects of
INFLUENCE QUANTITIES and INSTRUMENT PARAMETERS
3a – CHAMBER ASSEMBLY . 43
3b – MEASURING ASSEMBLY . 47
3c – CHAMBER and MEASURING ASSEMBLIES combined . 49
4.5 Classification of equipment according to LIMITS OF VARIATION. 49
4.5.1 FIELD-CLASS DOSIMETER. 49
4.5.2 REFERENCE-CLASS DOSIMETER. 49

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SIST EN 60731:1998
60731 © IEC:1997 – 5 –
Clause Page
5 CHAMBER ASSEMBLY performance requirements. 51
5.1 General performance requirements for (RADIOTHERAPY) IONIZATION CHAMBERS . 51
5.1.1 CHAMBER ASSEMBLY LEAKAGE CURRENT without irradiation . 51
5.1.2 Stability. 51
5.1.3 STABILIZATION TIME . 53
5.1.4 Post-irradiation leakage. 53
5.1.5 RATED or EFFECTIVE RANGE of DOSE RATE (continuous radiation) . 55
5.1.6 Maximum RATED DOSE per pulse (pulsed radiation) . 57
5.1.7 STRAY RADIATION . 59
5.1.8 Guard/collector insulation. 61
5.1.9 Cable microphony . 61
5.1.10 Polarity of polarizing voltage effect . 61
5.1.11 Electromagnetic compatibility . 63
5.2 Performance requirements particular to SHELL CHAMBERS . 63
5.2.1 Dependence on radiation quality. 65
5.2.2 RATED RANGE of field sizes . 69
5.2.3 CHAMBER orientation. 73
5.3 Performance requirements particular to PARALLEL-PLATE CHAMBERS . 73
5.3.1 Dependence on radiation quality. 75
5.3.2 RATED RANGE of field sizes. 77
HAMBER
5.3.3 C orientation. 77
5.4 Performance requirements particular to VENTED CHAMBERS. 79
5.4.1 Atmospheric pressure change . 79
5.4.2 Temperature . 79
5.4.3 Humidity. 81
5.5 Performance requirements particular to SEALED CHAMBERS . 81
5.5.1 Atmospheric pressure change . 81
5.5.2 Temperature . 83
6. MEASURING ASSEMBLY performance requirements. 83
6.1 General performance requirements for (RADIOTHERAPY) DOSIMETERS . 85
6.1.1 EFFECTIVE RANGES . 85
6.1.2 RESOLUTION of the display. 85
6.1.3 Repeatability . 87
6.1.4 Long-term stability. 87
6.1.5 STABILIZATION TIME. 89
6.1.6 Electromagnetic compatibility . 89
6.2 Performance requirements particular to DOSIMETERS . 91
6.2.1 ZERO DRIFT . 91
6.2.2 ZERO SHIFT . 93
6.2.3 NON-LINEARITY . 95

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SIST EN 60731:1998
60731 © IEC:1997 – 7 –
Clause Page
6.2.4 Range changing . 97
6.2.5 Dead time . 99
6.2.6 Temperature . 99
6.2.7 Humidity. 101
6.2.8 STRAY RADIATION effect. 101
6.2.9 Charge leakage. 103
6.2.10 DOSE RATE dependence of DOSIMETERS . 103
6.3 Performance requirements particular to DOSE RATEMETERS . 105
6.3.1 ZERO DRIFT . 105
6.3.2 ZERO SHIFT . 107
6.3.3 NON-LINEARITY . 109
6.3.4 Range changing . 111
6.3.5 RESPONSE TIME . 113
6.3.6 Temperature . 115
6.3.7 Humidity. 115
6.3.8 STRAY RADIATION effect. 117
6.4 Performance requirements particular to battery-operated MEASURING ASSEMBLIES 119
6.4.1 Operating battery life. 119
MEASURING
6.5 Performance requirements particular to supply mains-operated
ASSEMBLIES . 119
6.5.1 Mains voltage – static. 119
6.5.2 Mains voltage – variation during a measurement . 119
7 STABILITY CHECK DEVICE performance requirements . 121
7.1 General performance requirements for STABILITY CHECK DEVICES . 121
7.1.1 Long-term stability. 121
7.1.2 Repeatability . 121
8 Constructional requirements as related to PERFORMANCE CHARACTERISTICS . 123
8.1 Constructional requirements on CHAMBER ASSEMBLIES . 123
8.2 Constructional requirements on MEASURING ASSEMBLIES . 123
8.2.1 Adjustment of RESPONSE . 123
8.2.2 Display device. 123
8.2.3 Battery indication and compensation . 125
8.2.4 Input current threshold . 125
8.2.5 Automatic termination of measurement in the DOSE mode. 125
8.3 Constructional requirements on STABILITY CHECK DEVICES . 127
8.3.1 General constructional requirements on STABILITY CHECK DEVICES . 127
8.3.2 Constructional requirements particular to a radioactive type STABILITY
CHECK DEVICE . 127
8.3.3 Constructional requirements particular to an overall STABILITY CHECK
DEVICE. 127

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SIST EN 60731:1998
60731 © IEC:1997 – 9 –
Clause Page
8.4 Constructional requirements on PHANTOMs and build-up caps. 127
8.4.1 PHANTOMs . 127
9 Marking . 129
9.1 Marking required on CHAMBER ASSEMBLY . 129
9.2 Marking required on MEASURING ASSEMBLY . 129
9.3 Marking required on STABILITY CHECK DEVICE . 131
9.4 Marking required on PHANTOM or build-up cap . 131
10 ACCOMPANYING DOCUMENTS . 133
10.1 ACCOMPANYING DOCUMENTS for CHAMBER ASSEMBLY. 133
10.1.1 INSTRUCTIONS FOR USE of CHAMBER ASSEMBLY. 133
10.1.2 Test sheet for CHAMBER ASSEMBLY . 137
10.1.3 Calibration certificate for CHAMBER ASSEMBLY . 137
10.2 ACCOMPANYING DOCUMENTS for MEASURING ASSEMBLY. 139
10.2.1 INSTRUCTIONS FOR USE of MEASURING ASSEMBLY. 139
10.2.2 Test sheet for MEASURING ASSEMBLY . 141
10.2.3 Calibration certificate for MEASURING ASSEMBLY . 143
10.3 ACCOMPANYING DOCUMENTS for STABILITY CHECK DEVICE. 143
10.3.1 INSTRUCTIONS FOR USE of STABILITY CHECK DEVICE . 143
STABILITY CHECK DEVICE
10.3.2 Test sheet for . 145
10.3.3 Measurement certificate for STABILITY CHECK DEVICE . 145
10.4 ACCOMPANYING DOCUMENTS for PHANTOMs and build-up caps. 147
10.4.1 INSTRUCTIONS FOR USE of PHANTOMs and build-up caps . 147
Figures
1 Graphical illustration of values, error and uncertainty . 149
2 Test equipment for cable microphony. 151
3 Tolerance of depth in PHANTOM . 153
4 Tolerance of lateral position in PHANTOM . 153
Annexes
A Uncertainty of measurements . 155
B Bibliography . 179
C Alphabetical index of defined terms. 181

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SIST EN 60731:1998
60731 © IEC:1997 – 11 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MEDICAL ELECTRICAL EQUIPMENT –
DOSIMETERS WITH IONIZATION CHAMBERS
AS USED IN RADIOTHERAPY
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60731 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 1982 and its amend-
ment 1 (1987) and constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
62C/170/FDIS 62C/197/RVD
Full information on the voting for the approval of this standard can be found in the report of
voting indicated in the above table.
Annex A forms an integral part of this standard.
Annexes B and C are for information only.

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SIST EN 60731:1998
60731 © IEC:1997 – 13 –
INTRODUCTION
This International Standard is applicable to the performance of DOSIMETERS with IONIZATION
CHAMBERS as used in radiotherapy.
The effectiveness of treatment of PATIENTS receiving radiotherapy depends on the accuracy of
the dose of radiation received; an excessive dose can lead to excessive tissue damage, while
an insufficient dose will not provide the therapeutic benefit sought. The equipment covered by
this standard plays an essential part in achieving the required accuracy.
This standard is not concerned with the safety aspects of DOSIMETERS. The relevant IEC
standards covering safety depend upon the way in which the DOSIMETER is used:
– if it is used in physical contact with a PATIENT the particular requirements for safety
applying to DOSIMETERS with IONIZATION CHAMBERS as used in radiotherapy are contained in
IEC 60601-2-9. These requirements supplement the General requirements for safety of
MEDICAL ELECTRICAL EQUIPMENT
given in IEC 60601-1 (1988), amendment 1 (1991) and
amendment 2 (1995);
– if it is not used in physical contact with a PATIENT, then the safety requirements
for DOSIMETERS with IONIZATION CHAMBERS as used in radiotherapy are contained in
IEC 61010-1 (1990).
DOSIMETERS which comply with this standard should nevertheless be used in accordance with
the relevant national or international dosimetry protocol (code of practice). In particular,
measurements should be made to determine the ion collection efficiency and polarity effect of
the CHAMBER under the exact conditions of use.

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SIST EN 60731:1998
60731 © IEC:1997 – 15 –
MEDICAL ELECTRICAL EQUIPMENT –
DOSIMETERS WITH IONIZATION CHAMBERS
AS USED IN RADIOTHERAPY
1 Scope and object
1.1 Scope
1.1.1 This International Standard specifies the performance requirements of RADIOTHERAPY
DOSIMETERS, as defined in 3.1, intended for the measurement of ABSORBED DOSE TO WATER or
AIR KERMA (and their RATES) in photon or electron radiation fields as used in radiotherapy.
NOTE – Throughout this standard:
– if no material is specified, the term "ABSORBED DOSE" or "DOSE" means "ABSORBED DOSE TO WATER (in water)"
and the term "KERMA" means "AIR KERMA (in air)";
– when the quantity "AIR KERMA (in air)" in units "Gy" is used, the quantity "EXPOSURE" in units "C/kg" is also
allowable.
1.1.2 The dose-monitoring systems incorporated in radiotherapy treatment machines are not
covered by this standard, neither are the re-entrant ion chambers used for brachytherapy
source calibration.
1.1.3 This standard is applicable to the following types of DOSIMETER:
a) FIELD-CLASS DOSIMETERS normally used for
1) the measurement of KERMA or DOSE in a radiation beam, either in air or in a PHANTOM;
2) DOSE PATIENTS
in vivo skin surface or intracavitary measurements of on .
b) REFERENCE-CLASS DOSIMETERS normally used for the calibration of FIELD-CLASS
DOSIMETERS.
NOTE – REFERENCE-CLASS DOSIMETERS may be used as FIELD-CLASS DOSIMETERS.
1.2 Object
1.2.1 The object of this standard is:
a) to establish requirements for a satisfactory level of performance for RADIOTHERAPY
DOSIMETERS;
b) to standardize methods for the determination of compliance with this level of
performance.
1.2.2 Two levels of performance are specified:
– a lower level of performance applying to FIELD-CLASS DOSIMETERS;
– a higher level of performance applying to REFERENCE-CLASS DOSIMETERS.

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SIST EN 60731:1998
60731 © IEC:1997 – 17 –
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this International Standard. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to
agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the normative documents indicated below. Members of
IEC and ISO maintain registers of currently valid International Standards.
IEC 60051, Direct acting indicating analogue electrical measuring instruments and their
accessories
IEC 60417: 1973, Graphical symbols for use on equipment – Index, survey and compilation of
the single sheets
IEC 60601-1: 1988, Medical electrical equipment – Part 1: General requirements for safety
IEC 60601-2-9: 1987, Medical electrical equipment – Part 2: Particular requirements for the
safety, of dosimeters used in radiotherapy with electrically-connected radiation detectors
IEC 60788: 1984, Medical radiology – Terminology
IEC 61000-4-1: 1992, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 1: Overview of immunity tests – Basic EMC Publication
IEC 61000-4-2: 1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 2: Electrostatic discharge requirements – Basic EMC Publication
IEC 61000-4-3: 1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 3: Radiated electromagnetic field requirements
IEC 61000-4-4: 1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 4: Electrical fast transient /burst requirements – Basic EMC Publication
IEC 61000-4-5: 1995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 5: Surge immunity requirements
IEC 61000-4-6: 1996, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 6: Conducted disturbances induced by radio frequency fields above
9 kHz
IEC 61000-4-11: 1994, Electromagnetic compatibility (EMC) – Part 4: Testing and
measurement techniques – Section 11: Voltage dips, short interruptions and voltage variation
immunity tests
IEC 61010-1: 1990, Safety requirements for electrical equipment for measurement control, and
laboratory use – Part 1: General requirements
IEC 61187: 1993, Electrical and electronic measuring equipment – Documentation
ISO, 1993, International Vocabulary of basic and general terms in metrology
ISO 3534-1: 1993, Statistics – Vocabulary and symbols – Part 1: Probability and general
statistical terms
ICRU 33: 1980, Radiation Quantities and Units

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SIST EN 60731:1998
60731 © IEC:1997 – 19 –
3 Terminology and definitions
In this standard, the verbal form
– "shall" implies that compliance with a requirement is mandatory for compliance with the
standard;
– "should" implies that compliance with a requirement is strongly recommended but is not
mandatory for compliance with the standard;
– "may" implies that compliance with a requirement is permitted to be accomplished in a
particular manner for compliance with the standard.
The definitions given in this standard are generally in agreement with those in IEC 60788 and
ISO International vocabulary of basic and general terms in metrology, except that some
definitions have been made more restricted. Any such special definitions shall be regarded as
applying only to this standard.
Any terms not defined here in this clause have the meanings defined in the above publications
or are assumed to be in general scientific usage.
The defined terms are printed in SMALL CAPITALS throughout this standard.
For the purpose of this International Standard the following definitions apply:
IONIZATION CHAMBERS
3.1 (RADIOTHERAPY) DOSIMETER: Equipment which uses for the
measurement of AIR KERMA, ABSORBED DOSE, or the corresponding rates, in photon and electron
radiation as used in radiation therapy.
A RADIOTHERAPY DOSIMETER contains the following components:
– one or more CHAMBER ASSEMBLIES;
– a MEASURING ASSEMBLY (including possibly a separate display device);
– one or more STABILITY CHECK DEVICES (optional);
– one or more PHANTOMS or build-up caps (optional).
3.1.1 CHAMBER ASSEMBLY: The IONIZATION CHAMBER and all other parts to which the CHAMBER
is permanently attached, except the MEASURING ASSEMBLY. It includes the electrical fitting and
any permanently attached cable.
3.1.1.1 (IONIZATION) CHAMBER: An IONIZING RADIATION detector consisting of a CHAMBER filled
with air, in which an electric field insufficient to produce gas multiplication, is provided for the
collection at the electrodes of charges associated with the ions and the electrons produced in
the measuring volume of the detector by IONIZING RADIATION.
IONIZATION CHAMBER
NOTE – For this standard, the is considered to consist of the measuring volume, the
CHAMBER
collecting electrode, the guard electrode (if any), the outer electrode (which consists of the wall and
possibly a conducting coating), those parts of the insulator adjacent to the measuring volume, the build-up cap
and water-proof housing (if any).
There are several categories of IONIZATION CHAMBER:
3
a) SHELL CHAMBER: An IONIZATION CHAMBER with a measuring volume of between 0,1 cm
3
and 1,0 cm bounded by a rigid outer electrode mounted on a supporting stem. The
measuring volume is usually symmetrical about the axis of the stem and the CHAMBER is
intended to be used with the axis of symmetry perpendicular to the axis of the radiation
beam. There are two types of SHELL CHAMBER
:
1) THIMBLE CHAMBER: The outer electrode takes the form of a rigid cylindrical wall closed
at one end and mounted at the other on the supporting stem;

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SIST EN 60731:1998
60731 © IEC:1997 – 21 –
2) SPHERICAL CHAMBER: The outer electrod
...