EN 61674:1997

SLOVENSKI STANDARD
01-september-1998
Medical electrical equipment - Dosimeters with ionization chambers and/or semi-
conductor detectors as used in x-ray diagnosis imaging (IEC 61674:1997)
Medical electrical equipment - Dosimeters with ionization chambers and/or semi-
conductor detectors as used in X-ray diagnostic imaging
Medizinische elektrische Geräte - Dosimeter mit Ionisationskammern und/oder
Halbleiterdetektoren für den Einsatz an diagnostischen Röntgeneinrichtungen
Appareils électromédicaux - Dosimètres à chambres d'ionisation et/ou à détecteurs à
semi-conducteurs utilisés en imagerie de diagnostic à rayonnement X
Ta slovenski standard je istoveten z: EN 61674:1997
ICS:
11.040.50 Radiografska oprema Radiographic equipment
17.240 Merjenje sevanja Radiation measurements
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
INTERNATIONAL
Première édition
STANDARD
First edition
1997-10
Appareils électromédicaux –
Dosimètres à chambres d'ionisation et/ou
à détecteurs à semi-conducteurs utilisés
en imagerie de diagnostic à rayonnement X
Medical electrical equipment –
Dosimeters with ionization chambers and/or
semi-conductor detectors as used in X-ray
diagnostic imaging
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61674 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 7
INTRODUCTION . 9
Clause
1 Scope and object . 11
1.1 Scope. 11
1.2 Object . 11
2 Normative references. 11
3 Terminology and definitions . 13
4 General requirements. 27
4.1 Performance requirements. 27
4.2 REFERENCE VALUES and STANDARD TEST VALUES . 27
4.3 General test conditions . 29
4.3.1 STANDARD TEST CONDITIONS. 29
4.3.2 Statistical fluctuations. 29
4.3.3 STABILIZATION TIME. 29
4.3.4 Adjustments during test . 29
4.3.5 Batteries. 29
4.4 Constructional requirements as related to performance . 29
4.4.1 Components. 29
4.4.2 Display. 31
4.4.3 Indication of battery condition . 31
4.4.4 Indication of polarizing voltage failure . 31
4.4.5 Over-ranging. 31
4.4.6 Indication of reset or other inactive condition . 33
4.4.7 MEASURING ASSEMBLIES with multiple DETECTOR ASSEMBLIES . 33
4.4.8 Radioactive STABILITY CHECK DEVICE. 33
4.5 Uncertainty of measurement . 35
5 Limits of PERFORMANCE CHARACTERISTICS . 35
5.1 RELATIVE INTRINSIC ERROR . 35
5.2 Repeatability. 35
5.2.1 Repeatability in the ATTENUATED BEAM. 37
UNATTENUATED BEAM
5.2.2 Repeatability in the . 37
5.3 RESOLUTION of reading. 37
5.4 STABILIZATION TIME . 37
5.5 Effect of pulsed radiation on AIR KERMA and AIR KERMA LENGTH measurements . 37
5.6 Reset on AIR KERMA and AIR KERMA LENGTH ranges . 39
5.7 Effects of LEAKAGE CURRENT. 39
5.7.1 On all AIR KERMA RATE ranges. . 39
5.7.2 On all AIR KERMA and AIR KERMA LENGTH ranges. 39
5.8 Stability. 39
5.8.1 Long term stability . 39
5.8.2 Accumulated dose stability . 39
5.9 Measurements with a radioactive STABILITY CHECK DEVICE. 41

61674 © IEC:1997 – 5 –
Clause Page
6 LIMITS OF VARIATION for effects of INFLUENCE QUANTITIES . 41
6.1 Energy dependence of RESPONSE. 41
6.2 AIR KERMA RATE dependence of AIR KERMA and AIR KERMA LENGTH
measurements. 43
6.2.1 MEASURING ASSEMBLY . 43
6.2.2 IONIZATION CHAMBER – Recombination losses . 43
6.3 Dependence of DETECTOR RESPONSE on angle of incidence of radiation . 45
6.3.1 For non-CT DETECTORS. 45
6.3.2 For CT DETECTORS. 45
6.4 Operating voltage. 45
6.4.1 For mains-operated DOSIMETERS. 45
6.4.2 For battery-operated DOSIMETERS. 45
6.4.3 For mains rechargeable, battery-operated DOSIMETERS . 45
6.5 Air pressure. 47
6.6 Air pressure EQUILIBRATION TIME of the RADIATION DETECTOR . 47
6.7 Temperature and humidity . 47
6.8 Electromagnetic compatibility. 49
6.8.1 Electrostatic discharge. 49
6.8.2 Radiated electromagnetic fields . 49
6.8.3 Conducted disturbances induced by bursts and radio frequencies . 51
6.8.4 Voltage dips, short interruptions and voltage variations . 51
6.9 Field size. 51
6.10 EFFECTIVE LENGTH and spatial uniformity of RESPONSE of CT DOSIMETERS . 53
7 Marking. 53
7.1 DETECTOR ASSEMBLY . 53
7.2 MEASURING ASSEMBLY. 53
7.3 Radioactive STABILITY CHECK DEVICE . 55
8 ACCOMPANYING DOCUMENTS . 55
Tables
EFERENCE STANDARD TEST CONDITIONS
1R and . 57
2 Number of readings required to detect true differences Δ (95 % confidence level)
between two sets of instrument readings. 59
3RELATIVE INTRINSIC ERROR, I, for measurements in the ATTENUATED BEAM. 59
4RELATIVE INTRINSIC ERROR, I, for measurements in the UNATTENUATED BEAM and
in mammography. 61
5 Maximum values for the COEFFICIENT OF VARIATION, v . 61
max
6 Maximum values for the COEFFICIENT OF VARIATION, v . 61
max
7LIMITS OF VARIATION for the effects of INFLUENCE QUANTITIES . 63
Figure 1 – Limits on the RELATIVE INTRINSIC ERROR for AIR KERMA RATE measurements
in the ATTENUATED BEAM. 65
Annexes
A Bibliography . 67
B Index of defined terms . 69

61674 © IEC:1997 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
MEDICAL ELECTRICAL EQUIPMENT –
DOSIMETERS WITH IONIZATION CHAMBERS AND/OR
SEMI-CONDUCTOR DETECTORS AS USED
IN X-RAY DIAGNOSTIC IMAGING
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 61674 has been prepared by subcommittee 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/195/FDIS 62C/207/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.
Annexes A and B are for information only.

61674 © IEC:1997 – 9 –
INTRODUCTION
Diagnostic radiology is the largest contributor to man-made ionizing radiation to which the
public is exposed. The reduction in the exposure received by PATIENTS undergoing medical
radiological examinations or procedures has therefore become a central issue in recent years.
The PATIENT dose will be minimized when the X-ray producing equipment is correctly adjusted
for image quality and radiation output. These adjustments require that the routine
measurement of AIR KERMA, AIR KERMA LENGTH and/or AIR KERMA RATE be made accurately. The
equipment covered by this standard plays an essential part in achieving the required accuracy.
The DOSIMETERS
...