IEC 61676:2002

INTERNATIONAL IEC
STANDARD
First edition
2002-09
Medical electrical equipment –
Dosimetric instruments used for
non-invasive measurement of X-ray
tube voltage in diagnostic radiology
Appareils électromédicaux –
Instruments de dosimétrie pour la mesure
non invasive de la tension du tube radiogène
dans la radiologie de diagnostic
Reference number
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INTERNATIONAL IEC
STANDARD
First edition
2002-09
Medical electrical equipment –
Dosimetric instruments used for
non-invasive measurement of X-ray
tube voltage in diagnostic radiology
Appareils électromédicaux –
Instruments de dosimétrie pour la mesure
non invasive de la tension du tube radiogène
dans la radiologie de diagnostic
 IEC 2002  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
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V
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61676  IEC:2002(E)
CONTENTS
FOREWORD . 3
INTRODUCTION .5
1 Scope and object . 6
2 Normative references. 6
3 Terminology and definitions . 7
4 General performance requirements for measurement of PRACTICAL PEAK VOLTAGE
measurements .10
4.1 Quantity to be measured.10
4.2 Limits of PERFORMANCE CHARACTERISTICs .10
4.3 LIMITS OF VARIATION for effects of INFLUENCE QUANTITIES .13
4.4 Performance test procedures.15
5 Special instrumental requirements and marking .21
5.1 Requirements for the complete instruments .21
5.2 General .21
5.3 Display .22
5.4 Range of measurement.22
5.5 Connectors and cables .22
6ACCOMPANYING DOCUMENTS .22
6.1 General .22
6.2 Information provided.22
6.3 Instrument description .22
6.4 Detector.22
6.5 Delay time .22
6.6 Measurement window .22
6.7 Data outlet.23
6.8 Transport and storage .23
Annex A (informative) Recommended performance criteria for the invasive divider .24
Annex B (informative) Additional information on PRACTICAL PEAK VOLTAGE .25
Annex C (informative) Glossary of defined terms.32

61676  IEC:2002(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

MEDICAL ELECTRICAL EQUIPMENT –
Dosimetric instruments used for non-invasive measurement
of X-ray tube voltage in diagnostic radiology
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 specifications, 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 61676 has been prepared by subcommittee SC 62C: Equipment
for radiotherapy, nuclear medicine and radiation dosimetry, of IEC Technical Committee 62:
Electrical equipment in medical practice.
The text of this standard is based on the following documents:
FDIS Report on voting
62C/340/FDIS 62C/344/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 3.
Annexes A, B and C are for information only.
In this standard the following print types are used:
− requirements, compliance with which can be tested, and definitions: in roman type;
− notes, explanations, advice, general statements and exceptions: in small roman type;
− test specifications: in italic type;
− TERMS USED THROUGHOUT THIS STANDARD THAT HAVE BEEN DEFINED IN CLAUSE 3 OR IN IEC
60601-1 AND ITS COLLATERAL STANDARDS: IN SMALL CAPITALS.

– 4 – 61676  IEC:2002(E)
The committee has decided that the contents of this publication will remain unchanged until
2004. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
NOTE The committee is aware of the fact that this standard does not address all problems associated with non-
invasive high voltage measurements. In particular one influence quantity concerning the target condition is not
dealt with at all. Before this can be done, a substantial amount of measurements is still necessary to improve the
physical understanding of this influence quantity. On the other hand, for the reasons described in the introduction
there is an urgent need to publish this standard in order to assure that non-invasive measurements are comparable
to each other within tolerable uncertainties, regardless of differences in X-RAY GENERATOR, waveform or other
influence quantities (except target condition), which is not the case for the time being. The committee has decided
to revise this standard as soon as sufficient knowledge on the outstanding items is available.

61676  IEC:2002(E) – 5 –
INTRODUCTION
The result of a measurement of the X-RAY TUBE VOLTAGE by means of invasive or non-invasive
instruments is normally expressed in the form of one single number for the value of the tube
voltage, irrespective of whether the tube voltage is constant potential or shows a time
dependent waveform. Non-invasive instruments for the measurement of the X-RAY TUBE
VOLTAGE on the market usually indicate the ‘mean peak voltage’. But the quantity ‘mean peak
voltage’ is not unambiguously defined and may be any mean of all voltage peaks. It is
impossible to establish test procedures for the performance requirements of non-invasive
instruments for the measurement of the X-RAY TUBE VOLTAGE without the definition of the
quantity under consideration. Therefore, this Standard is based on a quantity recently
proposed in the literature to be called "PRACTICAL PEAK VOLTAGE". The PRACTICAL PEAK
VOLTAGE is unambiguously defined and applicable to any waveform. This quantity is related to
the spectral distribution of the emitted X-RADIATION and the image properties. X-RAY
GENERATORS operating at the same value of the PRACTICAL PEAK VOLTAGE will produce the
same low level contrast in the RADIOGRAMS, even when the waveforms of the tube voltages
are different. Detailed information on this concept is provided in Annex B. An example for the
calculation of the PRACTICAL PEAK VOLTAGE in the case of a “falling load” waveform is also
given in Annex B.
As a result of introducing a new quantity, the problem arises that this standard has been
written for instruments which were not explicitly designed for the measurement of the
PRACTICAL PEAK VOLTAGE. However, from preliminary results of a trial type test of a non-
invasive instrument currently on the market, it can be expected that future instruments and
most instruments on the market will be able to fulfil the requirements stated in this standard
without insurmountable difficulties. For the most critical requirements on voltage waveform
and frequency dependence of the RESPONSE, it turned out from these investigations that it is
even easier to comply with the standard by using the PRACTICAL PEAK VOLTAGE as the
measurement quantity.
The calibration and adjustment of the X-RAY TUBE VOLTAGE of an X-RAY GENERATOR is generally
performed by the MANUFACTURER using a direct INVASIVE MEASUREMENT. Instruments utilising
NON-INVASIVE MEASUREMENTS can also be used to check the calibration or to adjust THE X-RAY
TUBE VOLTAGE. These instruments are required to have uncertainties of the voltage
measurement comparable with the INVASIVE MEASUREMENT. One of the most important
parameters of diagnostic X-RAY EQUIPMENT is the voltage applied to the X-RAY TUBE, because
both the image quality in diagnostic radiology and the DOSE received by the PATIENT
undergoing radiological examinations are dependent on the X-RAY TUBE VOLTAGE. An overall
uncertainty below ±5 % is required, and this value serves as a guide for the LIMITS OF
VARIATION for the effects of INFLUENCE QUANTITIES.
———————
See annex B.
– 6 – 61676  IEC:2002(E)
MEDICAL ELECTRICAL EQUIPMENT –
Dosimetric instruments used for non-invasive measurement
of X-ray tube voltage in diagnostic radiology
1 Scope and object
This International Standard specifies the performance requirements of instruments as used in
the NO
...