EN 60601-2-8:1997

SLOVENSKI STANDARD
01-oktober-1998
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Medical electrical equipment - Part 2: Particular requirements for the safety of
therapeutic X-ray equipment operating in the range 10 kV to 1 MV (IEC 60601-2-8:1987)
Medizinische elektrische Geräte - Teil 2: Besondere Festlegungen für die Sicherheit von
Therapie-Röntgeneinrichtungen im Betriebsbereich von 10 kV bis 1 MV (IEC 60601-2-
8:1987)
Appareils électromédicaux - Partie 2: Règles particulières de sécurité pour les
équipements à rayonnement X de thérapie fonctionnant dans la gamme de 10 kV à 1 MV
(CEI 60601-2-8:1987)
Ta slovenski standard je istoveten z: EN 60601-2-8:1997
ICS:
11.040.50 Radiografska oprema Radiographic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
601-2-8
INTERNATIONAL
Première
édition
STAN DARD
First edition
Appareils électromédicaux
Deuxième partie:
Règles particulières de sécurité pour
groupes radiogènes de radiothérapie
Medical electrical equipment
Part 2:
Particular requirements for the safety of
therapeutic X-ray generators
© CEI 1987 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
utilisée sous quelque forme que ce soit
et par aucun procédé, in any form or by any means, electronic or mechanical,
électronique ou mécanique, y compris la
photocopie et les including photocopying and microfilm, without permission
microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher
Bureau central de la Commission Electrotechnique Internationale 3, rue de Varembé Genève Suisse
Commission Electrotechnique Internationale CODE PRIX
VV
International Electrotechnical Commission PRICE CODE
IEC
MemayHapoimaa 3nearporexHH4ecaaa Komuccma
• Pour prix, voir catalogue en vigueur
For price, see current catalogue

601-2-8 © I E C 1987
CONTENTS
Page
FOREWORD 9
PREFACE 9
SECTION ONE - GENERAL
Clause
1. Scope and object
1.1 Scope
1.2 Object
1.3 Particular Standards
1.3.101 Relation to the General Standard
1.3.102 Superseded I E C Standard
1.4 Environmental conditions
2. Terminology and definitions 13
3. General requirements
3.101 Conventional meaning of electrical quantities
4. General requirements for tests
4.1 Type tests and routine tests
4.7 Supply and test voltages, type of current, nature of supply, frequency 15
4.10 Moisture pre-conditioning treatment
5. Classification
6. Identification, marking and documents
6.1 Marking on the outside of equipment and equipment parts
6.2 Marking on the inside of equipment and equipment pa rts 19
6.7 Indicator lights and push-buttons
6.8 ACCOMPANYING DOCUMENTS
Power input 25
7.
SECTION TWO - SAFETY REQUIREMENTS
8. Basic safety categories 25
9. Removable protective means 25
10. Special environmental conditions
Special measures with respect to safety 25
11.
12. SINGLE FAULT CONDITION 25
SECTION THREE - PROTECTION AGAINST ELECTRIC SHOCK HAZARDS
13. General
14. Requirements related to classification
15. Limitation of voltage and/or current
16. Enclosures and PROTECTIVE COVERS
17. Insulation and PROTECTIVE IMPEDANCES 27
18. Earthing and potential equalization
19. Continuous LEAKAGE CURRENTS and PATIENT AUXILIARY CURRENTS 27
19.3 Allowable values 29
20. Dielectric strength 29
20.3 Values of test voltages 29
20.4 31
Tests
SECTION FOUR - PROTECTION AGAINST MECHANICAL HAZARDS
21. Mechanical strength
22. Moving parts
23. Surfaces, corners and edges
24. Stability and transportability

- 5-
601-2-8 © I E C 1987
Expelled parts
25.
Vibration and noise 33
26.
27. Pneumatic and hydraulic power
28. Suspended masses
SECTION FIVE - PROTECTION AGAINST HAZARDS FROM UNWANTED OR EXCESSIVE RADIATION
29. X-radiation
X-RAY GENERATORS 33
29.1 X-RADIATION generated by therapeutic
29.101 NORMAL CONDITION
29.102 SINGLE FAULT CONDITION
30. Alpha, beta, gamma, neutron radiation and other particle radiation
31. Microwave radiation
32. Light radiation (including visual radiation and lasers)
33. Infra-red radiation
Ultra-violet radiation 34.
35. Acoustical energy (including ultrasonics)
36. Electromagnetic compatibility
SECTION SIX - PROTECTION AGAINST HAZARDS OF EXPLOSIONS IN MEDICALLY USED ROOMS
37. General
ACCOMPANYING DOCUMENTS of ANAESTHETIC-PROOF EQUIPMENT 38. Classification, marking and
51 39. Common requirements for "AP" and "APG" equipment
Requirements and tests for ANAESTHETIC-PROOF EQUIPMENT, equipment parts or components (AP)
40.
SECTION SEVEN - PROTECTION AGAINST EXCESSIVE TEMPERATURES, FIRE AND OTHER HAZARDS, SUCH AS HUMAN ERRORS
42. Excessive temperatures
42.4 Compliance tests
43. Fire prevention
44. Overflow, spillage, leakage, humidity, ingress of liquids, cleaning, sterilization and disinfection
45. Pressure vessels and parts subject to pressure
46. Human errors
47. Electrostatic charges
Materials in APPLIED PARTS in contact with the body of the PATIENT 48.
49. Interruption of the power supply
SECTION EIGHT - ACCURACY OF OPERATING DATA AND PROTECTION AGAINST INCORRECT OUTPUT
50. Accuracy of operating data
53 50.1 Indication of radiation output
50.2 Agreement between indicated values and effective values
50.101 to 50.104 - REQUIREMENTS ON TESTS 59
50.101 General test conditions
50.102 Settings for measurements
50.103 Number of measurements
50.104 Measurements and evaluation
51. Protection against incorrect output
SECTION NINE - FAULT CONDITIONS CAUSING OVERHEATING AND/OR MECHANICAL DAMAGE; ENVIRONMENTAL TESTS
52. Fault conditions causing overheating and/or mechanical damage
53. Environmental tests
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601-2-8 © I EC 1987
SECTION TEN - CONSTRUCTIONAL REQUIREMENTS
54. General
55. Enclosures and covers
56. Components and general assembly 67
57. MAINS PARTS, components and layout
58. PROTECTIVE EARTH TERMINALS
59. Construction and layout 67
59.4 Oil containers
TABLE 101 - Permissible LEAKAGE RADIATION
TABLE 102 — LEAKAGE RADIATION from X-RAY SOURCE ASSEMBLIES with BEAM LIMITING DEVICES or
Permissible
therapeutic BEAM APPLICATORS
TABLE 103 — Diagram of measurements
APPENDIX AA — Terminology — Indices of terms

601-2-8 © I E C 1987
INTERNATIONAL ELECTROTECHNICAL COMMISSION
MEDICAL ELECTRICAL EQUIPMENT
Part 2: Particular requirements for the safety of therapeutic
X-ray generators
FOREWORD
I) The formal decisions or agreements of the I E C on technical matters, prepared by Technical Committees on which all
the National Committees having a special interest therein are represented, express, as nearly as possible, an international
consensus of opinion on the subjects dealt with.
2) They have the form of recommendations for international use and they are accepted by the National Committees in that
sense.
In order to promote international unification, the I E C expresses the wish that all National Committees should adopt
3)
the text of the I E C recommendation for their national rules in so far as national conditions will permit. Any divergence
between the I E C recommendation and the corresponding national rules should, as far as possible, be clearly indicated
in the latter.
The I E C has not laid down any procedure concerning marking as an indication of approval and has no responsibility
4)
when an item of equipment is declared to comply with one of its recommendations.
PREFACE
This Particular Standard has been prepared by Sub-Committee 62B: X-ray Equipment Operating up to 400 kV and
Accessories, of I E C Technical Committee No. 62: Electrical Equipment in Medical Practice.
The text of this standard is based upon the following documents:
Report on Voting
Six Months' Rule
62B(CO)64
62B(CO)49
Further information can be found in the Report on Voting indicated in the table above.
This Particular Standard amends and supplements I E C Publication 601-1 (first edition 1977): Safety of Medical Electrical
Equipment. Part 1: General Requirements, hereinafter referred to as the General Standard. The requirements of this
Particular Standard take priority over those of the General Standard. The title of the General Standard will be changed in
the next editions to read: Medical Electrical Equipment, Part 1: General Requirements for Safety. This change is anticipated
in the title of this Particular Standard.
The numbering of sections, clauses and sub-clauses of this Particular Standard corresponds with that of the General
Standard.
ures which are additional to those of the General Standard are numbered starting from 101; additional
Sub-clauses or fi g
aa), bb), etc.
appendices are lettered AA, BB, etc. and additional items
In this standard, the following print types are used:
requirements, compliance with which can be tested and definitions: in roman type;
explanations, advice, introductions, general statements, exceptions and references: in smaller type;
test specifications: in italic type;
788 OR IN THIS
OF THE GENERAL STANDARD, IN I E C PUBLICATION
TERMS DEFINED IN CLAUSE 2
PARTICULAR STANDARD: SMALL CAPITALS.

— 11 —
601-2-8 © I E C 1987
MEDICAL ELECTRICAL EQUIPMENT
Part 2: Particular requirements for the safety of therapeutic
X-ray generators
SECTION ONE — GENERAL
1. Scope and object
This clause of the General Standard applies except as follows:
1.1 Scope
Addition:
This Particular Standard applies to therapeutic X -RAY GENERATORS that operate with
NOMINAL X-RAY TUBE VOLTAGES from 10 kV to 400 kV inclusive when connected to alternating
current SUPPLY MAINS.
1.2 Object
Replacement:
The object of this Particular Standard is to establish the particular requirements for safety
including the requirements for accuracy and reproducibility of performance to the extent that
these are related to RADIATION QUALITY and the quantity of IONIZING RADIATION produced and
thus must be considered as aspects of safety.
An object of this Particular Standard is to present the general functional requirements of
the demand for safety, rather than any particular technological means of implementation.
1.3 Particular Standards
Additional sub-clauses:
1.3.101 Relation to the General Standard
This Particular Standard refers to, and is to be read in conjunction with I E C Publication
601-1 (1977): Safety of Medical Electrical Equipment, Part 1: General Requirements and its
Amendment No. 1 (1984).
For brevity Part 1 is referred to in this Particular Standard either as the "General Standard"
or as the "General Requirement(s)".
The term "this Standard" is used to make reference to the General Standard and this
Particular Standard taken together.
A requirement of this Particular Standard replacing or modifying requirements of the
General Standard takes precedence over the corresponding General Requirement(s).
Where there is no corresponding clause or sub-clause in this Particular Standard, the clause
or sub-clause of the General Standard applies without modification.

— 13 —
601-2-8 © I EC 1987
Where it is intended that any part of the General Standard, although possibly relevant, is
X-RAY GENERATORS, a statement to that effect is given in this
not to be applied to therapeutic
Particular Standard.
1.3.102 Superseded I E C Standard
particularly of
X-RAY EQUIPMENT,
This Standard deals with some aspects of therapeutic
and sub-assemblies thereof, that were covered by I E C Publi-
therapeutic X-RAY GENERATORS
cation 407 (1973): Radiation Protection in Medical X-ray Equipment 10 kV to 400 kV.
Within its scope, this Particular Standard supersedes the corresponding requirements of
I E C Publication 407.
1.4 Environmental conditions
a) Transport and storage
Item 2) a)
Replacement:
v) of Sub-clause
an ambient temperature between —20 °C and + 70 °C (see Item
a)
6.1 of the General Standard regarding marking of the packing).
b) Operation
2) Power supply
Item a) A SUPPLY MAINS having:
Replacement of the sixth dash:
a frequency which does not deviate more than 1% from the nominal value for
—
all frequencies.
Replacement of the second paragraph in small print:
An alternating voltage is considered in practice to be sinusoidal if any instantaneous value of the waveform
concerned differs from the instantaneous value of the ideal waveform at the same moment by no more than ±2%
of the peak value of the ideal waveform.
Terminology and definitions
2.
This clause of the General Standard applies except as follows:
Addition:
this Particular Standard, terms in capital letters are used as defined in:
In
— the General Standard
I E C Publication 788 (1984): Medical Radiology—Terminology
—
An index of these terms, referring to the standards mentioned is given in Appendix AA.

— 15 —
601-2-8 I E C 1987 ©
3. General requirements
This clause of the General Standard applies except as follows:
Additional sub-clause:
3.101 Conventional meaning of electrical quantities
In this Particular Standard unless otherwise indicated, values of X-RAY TUBE VOLTAGE refer
to peak values.
4. General requirements for tests
This clause of the General Standard applies except as follows:
4.1 Type tests and routine tests
a) Type tests
Addition:
The tests described in this Particular Standard are type tests, which are to be carried out
under controlled conditions, usually prevailing only in test laboratories.
4.7 Supply and test voltages, type of current, nature of supply, frequency
Additional item:
in air for compliance
aa) For all tests for the measurement of AIR KERMA and AIR KERMA RATE
and STRAY RADIATION it is assumed that the
with requirements on LEAKAGE RADIATION
used for the test is delivering its ouput at its NOMINAL VALUES.
SUPPLY MAINS
4.10 Moisture pre-conditioning treatment
Addition (see Sub-clause 1.3.101):
X-RAY GENERATORS likely to be
This test shall be applied only to those parts of therapeutic
influenced by the climatic conditions that are simulated by the test.
X-RAY GENERATOR as a whole, the treatment
Where it is not practicable to treat a therapeutic
may be given sequentially to separate parts.
Also, where testing cannot be carried out without dismantling or reassembling, a period longer
than that required in the General Standard may elapse between treatment and testing.
5. Classification
This clause of the General Standard applies except as follows:
5.1
Replacement:
Therapeutic X-RAY GENERATORS shall be classified as CLASS I EQUIPMENT.

— 17 —
601-2-8 © I E C 1987
Replacement:
5.2
TYPE B EQUIPMENT.
X-RAY GENERATORS shall be classified as
Therapeutic
5.3 Replacement:
are ordinary MEDICAL ELECTRI-
Unless otherwise specified, therapeutic X-RAY GENERATORS
(enclosed equipment without protection against ingress of liquids).
CAL EQUIPMENT
5.6 Replacement:
X-RAY GENERATORS shall be classified as suitable for
Unless otherwise specified, therapeutic
LOADINGS;
SUPPLY MAINS in the STAND-BY STATE and for specified
continuous connection to the
of Sub-clause 6.1 and Sub-clause 6.8.5.
see Item m)
6. Identification, marking and documents
This clause of the General Standard applies except as follows:
6.1 Marking on the outside of equipment and equipment parts
Addition at the beginning of the sub-clause:
and their constituent sub-assemblies and components shall
X-RAY GENERATORS
Therapeutic
be appropriately marked if their correlation to one another influences safety; see also Sub-
clause 6.8.1.
g) Connection to the supply
Addition at the end of the item:
X-RAY GENERATORS that are specified to be permanently installed, the
For therapeutic
of Sub-clause 6.1 of the General Standard may be stated
g)
information required in Item
ACCOMPANYING DOCUMENTS only.
in the
h) Supply frequency (in hertz)
Addition at the end of the item:
that are specified to be permanently installed, the
For therapeutic X-RAY GENERATORS
h) of Sub-clause 6.1 of the General Standard may be stated
information required in Item
only.
in the ACCOMPANYING DOCUMENTS
Power input
j)
Addition at the end of the item:
that are specified to be permanently installed, the
For therapeutic X-RAY GENERATORS
of Sub-clause 6.1 of the General Standard may be stated
information required in Item j)
only.
in the ACCOMPANYING DOCUMENTS
m) Mode of operation
Replacement:
The mode of operation — where appropriate, together with maximum permissible ratings
see Sub-clauses 5.6 and 6.8.5.
ACCOMPANYING DOCUMENTS;
— shall be stated in the
601-2-8 © I E C 1987 — 19 —
n) Fuses
Addition at the end of the item.
For therapeutic X-RAY GENERATORS that are specified to be permanently installed, the
information required in Item n) of Sub-clause 6.1 of the General Standard may be stated
in the ACCOMPANYING DOCUMENTS only.
t) Cooling conditions
Replacement:
The cooling requirements for the safe operation of a therapeutic X-RAY GENERATOR, or
a sub-assembly thereof, shall be indicated in the ACCOMPANYING DOCUMENTS, including,
as appropriate:
the maximum heat dissipation into the surrounding air, given separately for each
sub-assembly that dissipates more than 100 W and might be separately located on
installation;
— the maximum heat dissipation into forced air cooling devices and the corresponding
flow rate and temperature rise of the forced air stream;
— the maximum heat dissipation into a cooling medium utility and the highest permiss-
ible input temperature, minimum flow rate and pressure requirements for the utility.
Additional item:
aa) Marking of compliance
If for a therapeutic X-RAY GENERATOR compliance with this Standard is to be marked on
MODEL
the outside of the equipment, such marking shall be made in combination with the
OR TYPE REFERENCE as follows:
...*) IEC 601-2-8 1987
*) MODEL OR TYPE REFERENCE
Marking indicating compliance of equipment, or sub-assembly thereof, with the require-
ments of this Standard shall be made only if compliance of the equipment, or the
sub-assembly is complete.
6.2 Marking on the inside of equipment and equipment parts
Item c)
Addition:
This marking does not apply to parts containing high voltage circuits of X-RAY TUBE
ASSEMBLIES and of HIGH VOLTAGE TRANSFORMER ASSEMBLIES.
6.7
Indicator lights and push-buttons
a) Colours of indicator lights
Addition:
Sub-clauses 29.102.7 and 50.1.107 of this Particular Standard, and Sub-clauses 6.7 and 56.8 of the General
Standard, deal with indicators and indicator lights.

601-2-8 © I E C 1987 — 21
6.8 ACCOMPANYING DOCUMENTS
6.8.1 General
Addition at the end of the sub-clause:
X-RAY
The ACCOMPANYING DOCUMENTS shall clearly state the identity of the therapeutic
GENERATOR, or sub-assembly thereof, to which they refer.
All particulars required to be marked under Sub-clause 6.1 shall also be stated in the
ACCOMPANYING DOCUMENTS.
This Particular Standard contains no requirements concerning the language(s) in which
ACCOMPANYING DOCUMENTS are to be provided.
Attention is drawn to the fact that ACCOMPANYING DOCUMENTS in a language other than that in which they are supplied
and approved by the manufacturer of the equipment or sub-assembly need a careful check by an expert who, wherever
possible, should be authorized by the manufacturer to act in this capacity.
The ACCOMPANYING DOCUMENTS shall state the language(s) in which they were originally
drafted, approved or supplied by the manufacturer and shall give a reference identifying at
least one original version.
6.8.2 INSTRUCTIONS FOR USE
a) General information
Addition at the end of the item:
The shall specify the electrical output data of the therapeutic X-RAY
INSTRUCTIONS FOR USE
GENERATOR, or sub-asssembly thereof, when LOADING a specified X-RAY TUBE or specified
X-RAY TUBE ASSEMBLY.
The shall specify the maximum permitted X-RAY CURRENT at
INSTRUCTIONS FOR USE
representative values over the entire range of specified X-RAY TUBE VOLTAGE.
Warning statements and the explanation of graphical symbols shall be given in the
INSTRUCTIONS FOR USE.
6.8.3 Technical description
a) General
Addition at the end of the item:
The technical description shall contain appropriate instructions for the connection of the
therapeutic X-RAY GENERATOR to the SUPPLY MAINS.
The position of a reference centre as the centre of a sphere of 10 mm radius containing
the FOCAL SPOT shall be described in the ACCOMPANYING DOCUMENTS.
In this Particular Standard the centre of the sphere is referred to as the reference centre and is used only to
describe applicable distances for the requirements on LEAKAGE RADIATION; see Sub-clause 29.1.101.

601-2-8 (D I E C 1987 — 23 —
ACCOMPANYING DOCUMENTS
6.8.5 Reference to
Addition:
Clauses and sub-clauses of this Particular Standard in which additional requirements concerning the content of
the ACCOMPANYING DOCUMENTS are given:
Information on:
6 Ig)
Connection to the supply
6 1h)
Supply frequency
Power input 6 1j)
Mode of operation 6 1m)
6 in)
Fuses
Cooling conditions 6 It)
8.1
Identity of ACCOMPANYING DOCUMENTS 6
6 8.1
Warning statements
Explanations of graphical symbols 6 8.1
6 8.1
Original language(s) of ACCOMPANYING DOCUMENTS
Electric output data 6 8.2a)
20.3
29.1.101
29.1.102
29.1.104
29 1.105
(NOMINAL X-RAY TUBE VOLTAGE)
50.2.101
50 101 I
(X-RAY TUBE, X-RAY TUBE ASSEMBLY)
50.102.1
50.102.2
6 8.3
Technical description
6 8.2
Maximum permissible X-RAY TUBE CURRENT
Instructions on connection to the SUPPLY MAINS 6 8.3
6 8.3
Position of the FOCAL SPOT (reference centre)
6 8.101
Statement of compliance
18c)
Functional currents on protective earth connections
29 1
Sub-assemblies and components
Location of TREATMENT CONTROL PANEL for operation up to and including 50 kV 29 1.101
and 29.1.105a)
29 1.101
RADIATION APERTURE Of X-RAY TUBE HOUSING
1.I03a)
Sub-assemblies and accessories specified 29
29 1.103b)
BEAM APPLICATORS
29 1.103b)
Values of FILTRATION
1.105b)
Technical details on connections for indication and control 29
and 29.1.105c)
Hand held X-RAY TUBE ASSEMBLY 29 1.106a)
PROTECTIVE DEVICES 29 1.106b)
29 1.106b)
Wearing Of PROTECTIVE CLOTHING
Combinations of X-RAY TUBE VOLTAGE and ADDED FILTER 29 102
and 50.2.103
of 29 102 3a)
Movement RADIATION SOURCE
Special state of operating the X-RAY TUBE 29 102
29 102 5
Combinations of parametres
and 29.102.6
BEAM APPLICATORS With ADDED FILTER 29 102
42 4-3)
ANODE INPUT POWER of X-RAY TUBE
Periods of intermittent LOADINGS
50 1.101
Information on radiation output
RADIATION FIELD 50 1.103
Guidance about determination of distance and
Maintenance of storage capability 50 1.109d)
50 2.101
BEAM LIMITING DEVICE
Maximum continuous power 50 101 1
50 104 3
HALF VALUE LAYERS for RADIATION QUALITIES
59 4
Information on oil level
601-2-8 © I E C 1987 — 25 —
Additional sub-clause:
6.8.101 Statement of compliance
If for a therapeutic X -RAY GENERATOR compliance with this Standard is to be stated, this shall
be made as follows:
Therapeutic X-ray generator .*) IEC 601-2-8/1987
*)
MODEL OR TYPE REFERENCE
7. Power input
This clause of the General Standard applies.
SECTION TWO SAFETY REQUIREMENTS
Clauses 8 to 12 of the General Standard apply.
8. Basic safety categories
9. Removable protective means
10. Special environmental conditions
11. Special measures with respect to safety
12. SINGLE FAULT CONDITION
SECTION THREE — PROTECTION AGAINST ELECTRIC SHOCK HAZARDS
Clauses 13 and 14 of the General Standard apply.
13. General
14. Requirements related to classification
15. Limitation of voltage and/or current
This clause of the General Standard applies except as follows:
Additional items:
aa) HIGH VOLTAGE CABLE CONNECTIONS shall be designed that the use Of TOOLS
Detachable SO
is required to disconnect them.
bb) Provision shall be made to prevent the appearance of an unacceptably high voltage in
the MAINS PART or in any other low voltage circuit as a result of a defect or switching
phenomenon in the high voltage circuit.

601-2-8 © I E C 1987 — 27 —
This can be achieved for example:
– by provision of a winding layer or a conductive screen connected to the PROTECTIVE EARTH TERMINAL between
high voltage and low voltage circuits,
– by provision of a voltage limiting device across terminals to which external devices are connected and between
which an excessive voltage might arise if the external path becomes discontinuous.
Compliance shall be checked by inspection of design data and construction.
16. Enclosures and PROTECTIVE COVERS
This clause of the General Standard applies except as follows:
Additional item:
aa) Accessible high voltage cables carrying X-RAY TUBE CURRENT shall incorporate a flexible
conductive screen having a maximum resistance of 1 5 -2m-' of length covered with a
non-conductive material capable of protecting the screen against mechanical damage in
NORMAL USE.
HIGH VOLTAGE GENERA-
The screen shall be connected to the conductive enclosure of the
TOR and to that of the X-RAY TUBE ASSEMBLY.
Compliance shall be checked by visual inspection and by measurement.
The flexible conductive screen is not to be recognized as satisfying a requirement for a protective earth
connection between the devices connected by the cable.
17. Insulation and PROTECTIVE IMPEDANCES
This clause of the General Standard applies.
18. Earthing and potential equalization
This clause of the General Standard applies except as follows:
Item c)
Addition:
For special applications of X-RAY SOURCE ASSEMBLIES or for radiation measuring devices,
parts connected to the PROTECTIVE EARTH TERMINAL and intended to be inserted into body
cavities are permitted to carry functional currents.
In such cases, adequate information shall be included in the INSTRUCTIONS FOR USE,
explaining the particular risks and the conditions, such as the integrity of the protective
earth connection, necessary for maintaining safe operating conditions.
19. Continuous LEAKAGE CURRENTS and PATIENT AUXILIARY CURRENTS
This clause of the General Standard applies except as follows:

— 29 —
601-2-8 © I E C 1987
19.3 Allowable values
Addition at the beginning of the sub-clause:
and sub-assemblies thereof, the column on Type B and
For therapeutic X-RAY GENERATORS
of Table IV including the Notes on it of the General
the lines on EARTH LEAKAGE CURRENT
Standard apply.
are permitted for each sub-assembly of
The permissible values of EARTH LEAKAGE CURRENT
SUPPLY
that is supplied by its own exclusive connection to the
a therapeutic X-RAY GENERATOR
or to a central connection point, if the latter is fixed and permanently installed.
MAINS
A fixed and permanently installed central connection point may be provided inside the outer
X-RAY
HIGH VOLTAGE GENERATOR. If other sub-assemblies such as an
enclosure or cover of the
ASSOCIATED EQUIPMENT are connected to the central connection point, the
SOURCE ASSEMBLY or
between such a central connection point and the external protective
EARTH LEAKAGE CURRENT
system may exceed the permissible values for any one of the single devices connected.
X-RAY EQUIPMENT IS
EARTH LEAKAGE CURRENTS within the environment of an
Rationale. — The limitation of the
intended to limit electrical potential differences between accessible parts.
Item e)
Addition:
SUPPLY MAINS
with detachable connection to the
For therapeutic X-RAY EQUIPMENT
c) of
and not containing parts intended to be inserted into body cavities — see Item
NORMAL CONDITION and SINGLE FAULT
EARTH LEAKAGE CURRENT under
Clause 18 — the
ENCLOSURE LEAKAGE CURRENT under SINGLE FAULT
shall not exceed 2 mA. The
CONDITION
ADDITIONAL PROTECTIVE EARTH CONDUC-
CONDITION shall not exceed 2 mA even though no
TOR is connected.
Additional item:
with detachable connection to the SUPPLY MAINS con-
aa) If therapeutic X-RAY EQUIPMENT
tains parts intended to be inserted into body cavities, the need for connecting an
INSTRUCTIONS FOR
shall be described in the
ADDITIONAL PROTECTIVE EARTH CONDUCTOR
USE.
Dielectric strength
20.
This clause of the General Standard applies except as follows:
20.3 Values of test voltages
Addition:
The dielectric strength of the electrical insulation of high voltage circuits shall be sufficient
a) of Sub-clause 20.4.
to withstand the test voltages for the durations given in Item
connected and with a test voltage of 1.2 times
The test shall be made without an X-RAY TUBE
of the therapeutic X-RAY GENERATOR.
the NOMINAL X-RAY TUBE VOLTAGE
connected and
can be tested only with the X-RAY TUBE
If the therapeutic X-RAY GENERATOR
be tested with a test
does not allow the therapeutic X-RAY GENERATOR to
if the X-RAY TUBE
the test voltage shall be lower but not
NOMINAL X-RAY TUBE VOLTAGE,
voltage of 1.2 times the
less than 1.1 times that voltage.

601-2-8 © I E C 1987 — 31 —
20.4
Tests
Item a)
Addition:
The high-voltage circuits of therapeutic X-RAY GENERATORS shall be tested by applying a
test voltage of 50% of its final value according to Sub-clause 20.3 and increasing it during
a time of 10 s to the final value which then shall be maintained for a duration of 15 min.
Item d)
Addition:
During the dielectric strength test, the test voltage in the high voltage circuit should be
kept as close as possible to 100% but shall be within the range of 100% and 105% of
the values required.
Rationale. — The dielectric strength test may cause permanent damage to the insulation of high voltage circuits.
Therefore the test voltages required in Sub-clause 20.3 should not exceed those necessary to compensate for
the uncertainty of the value of the high voltage applied.
Item f)
Addition:
During the dielectric strength test of the high voltage circuits of therapeutic X-RAY
GENERATORS
tested without the X-RAY TUBE ASSEMBLY slight corona discharges may be
disregarded if they cease when the test voltage is lowered to 110% of the voltage to which
the test condition is referred.
SECTION FOUR — PROTECTION AGAINST MECHANICAL HAZARDS
Clauses 21 to 23 of the General Standard apply.
21.
Mechanical strength
22. Moving parts
23. Surfaces, corners and edges
24. Stability and transportability
This clause of the General Standard applies except as follows:
Addition at the beginning of the clause:
MOBILE therapeutic X-RAY GENERATORS shall be equipped with wheel locks and/or braking
system appropriate to the intended modes of use and sufficient to ensure that movements on
an incline of 0.09 radians (5°) can be prevented.

601-2-8 © I E C 1987 — 33 —
Clauses 25 to 28 of the General Standard apply.
25. Expelled parts
26. Vibration and noise
27.
Pneumatic and hydraulic power
28. Suspended masses
SECTION FIVE — PROTECTION AGAINST HAZARDS FROM UNWANTED OR
EXCESSIVE RADIATION
29. X-radiation
This clause of the General Standard applies except as follows:
29.1 Additional heading:
X-RADIATION X-RAY GENERATORS
generated by therapeutic
Replacement:
The requirements of this sub-clause apply to therapeutic X-RAY GENERATORS in NORMAL USE.
The requirements shall be met for each specified X-RAY TUBE HOUSING whatever X-RAY TUBE
specified as suitable it may contain, and for all combinations of components and operating
conditions specified for the X-RAY GENERATOR and relevant to the requirements.
Additional sub-clauses:
29.1.101 LEAKAGE RADIATION from the X-RAY SOURCE ASSEMBLY during treatments
Limitation of
The X-RAY SOURCE ASSEMBLY, which for
AIR KERMA RATE from LEAKAGE RADIATION from the
the purposes of this sub-clause shall be considered to include any BEAM LIMITING DEVICE only
if it is permanently attached to the X-RAY TUBE HOUSING (see Item a) of Sub-clause 29.1.103),
shall not exceed the values given in Table 101.

601-2-8 © I E C 1987
—35
TABLE 101
LEAKAGE RADIATION
Permissible
Operating
Maximum permissible AIR KERMA RATE
X-RAY TUBE VOLTAGE
Above 150 kV 10 mGy (X =1150 mR) * in one hour at a distance of 1 m from the
reference centre and 300 mGy (X = 34.5 R) in one hour at a distance
of 50 mm from the surface of the X-RAY SOURCE ASSEMBLY
Up to and including 150 kV 1 mGy (X=115 mR)* in one hour at a distance of 1 m from the
reference centre
Up to and including 50 kV for
1 mGy (X=115 mR)* in one hour at a distance of 50 mm from the
X-RAY SOURCE ASSEMBLIES de-
X-RAY SOURCE ASSEMBLY
surface of the
signed and specified to be held
by hand **
* According to ICRP 33 the numerical value of the earlier levels of 1 000 mR and 100 mR have been transferred
in SI units as 10 mGy and 1 mGy.
TREATMENT
** See Item a) of Sub-clause 29.1.106 and for those in equipment not designed and specified to locate the
CONTROL PANEL outside the TREATMENT ROOM, see Item a) of Sub-clause 29.1.105.
Compliance shall be checked under the following conditions:
RADIATION APERTURE of the X-RAY TUBE HOUSING shall be covered SO that the AIR KERMA
The
RATE on the RADIATION BEAM AXIS is reduced by a factor of at least 106. The dimensions and
location of the aperture shall be stated in the ACCOMPANYING DOCU MENTS. The cover shall
not extend outside the RADIATION BEAM by more than 5 mm.
AIR KERMA RATE shall be made with the therapeutic X-RAY GENERATOR
Measurements of the
operated under conditions that are possible within the specifications given in the ACCOMPAN-
YING DOCUMENTS and are the least favourable with regard to compliance with the require-
ments.
Normally the least favourable conditions, that is, conditions that would lead to maximum LEAKAGE RADIATION,
shall be determined by inspection of the specified conditions of operation.
Measurements made at 1 m distance from the reference centre (see note in Sub-clause 6.8.3)
shall average the AIR KERMA RATE over an area of 100 cm2 in the plane of measurement with
no principal linear dimension greater than 20 cm.
over
In order to average the AIR KERMA RATE from small beams of LEAKAGE RADIATION
the appropriate area the RADIATION DETECTOR may have an entry window with an area of
100 cm2.
X RA Y SOURCEASSEMBL Yshall
Measurements made at 50 mm distance from the surface of the
over an area of 10 cm
average the AIR KERMA RATE 2 with no principal linear dimension greater
than 4 cm.
RADIATION DETECTOR may have an entry window with an area of 10 cm2.
The
AIR KERMA RATE shall be made at the applicable distances given in
Measurements of
Table 101, unless this is not physically possible, in which case measurements may be made
at another distance, as close as possible to the required distance, and referred to the required
distance.
601-2-8 © I E C 1987 — 37 —
LEAKAGE RADIATION and unwanted RADIATION from the X-RAY SOURCE
29.1.102 Limitation of
ASSEMBLY at times other than during treatments.
X-RAY GENERATORS, both those in
The requirements of this sub-clause are for all therapeutic
can remain energized after a treatment has been terminated inten-
which the X-RAY TUBE
tionally, and those in which the X-RAY TUBE is de-energized at the end of a treatment.
When measurement is started 5 s after any one operation or event that stops the emission of
the AIR KERMA RATE from LEAKAGE RADIATION from the X-RAY SOURCE
RADIATION BEAM, the
ASSEMBLY and from RADIATION in the direction of the RADIATION BEAM shall not exceed a total
of 0.02 mGy (X=2,3 mR)* in one hour at a distance of 1 m from the reference centre, and
shall not exceed a total of 0.2 mGy (X = 23 mR) in one hour at a distance of 50 mm from the
surface of the X-RAY SOURCE ASSEMBLY.
* See Note to Table 101, Sub-clause 29.1.101.
Compliance shall be checked under the following conditions:
The therapeutic X-RA Y GENERATOR shall be operated under conditions of use that are possible
ACCOMPANYING DOCUMENTS, and are the least favourable
within the specification given in the
with regard to this requirement, and are specified as applicable for persons other than
PATIENTS to be near the X-RA Y SOURCE ASSEMBLY when a treatment is not being carried out;
Measurements made at 1 m distance from the reference centre shall average the AIR KERMA
over an area of 100 cm2 in the plane of measurement with no principal linear dimension greater
than 20 cm;
Measurements made at 50 mm from the surface of the X RA Y SOURCEASSEMBLY shall average
the AIR KERMA over an area of 10 cm2 with no principal linear dimension greater than 4 cm;
shall be made at the applicable distances required in this
— Measurements of AIR KERMA
sub-clause, unless this is not physically possible, in which case measurements may be made
at another distance, as close as possible to the required distance, and referred to the required
distance.
29.1.103 Limitation of unwanted RADIATION from the X-RA Y SOURCE ASSEMBL Y with BEAM LIMITING
DEVICES or therapeutic BEAM APPLICATORS
a) Attachment of accessories
Any BEAM LIMITING DEVICE supplied Or specified shall be:
— an integral and permanent part of a removable therapeutic BEAM APPLICATOR or,
or,
— an integral and permanent part of a removable adjustable BEAM LIMITING DEVICE
permanently attached to the X-RAY TUBE HOUSING (see Sub-clause 29.1.101).
—
Any removable therapeutic BEAM APPLICATOR and any removable adjustable BEAM
LIMITING DEVICE shall be so designed that the only manner in which they can be attached
is directly to the X-RAY TUBE ASSEMBLY.

601-2-8 © I E C 1987 — 39 —
RADIATION
b) Limitation of to the PATIENT
For any removable adjustable BEAM LIMITING DEVICE and any removable therapeutic BEAM
APPLICATOR
(other than those specified for INTRACAVITARY RADIOTHERAPY) fitted to the
X-RAY TUBE ASSEMBLY,
the AIR KERMA RATES outside the RADIATION FIELD shall not exceed
the percentages given in Table 102 of the
AIR KERMA RATES on the RADIATION BEAM AXIS.
TABLE
Permissible LEAKAGE RADIATION from X -RAY SOURCE ASSEMBLIES
with BEAM LIMITING DEVICES
or therapeutic BEAM APPLICATORS
Lateral dimensions of the lead block Maximum
AIR KERMA RATE at all places more than 20 mm
from the edge of the lead block
1.5 times the lateral dimensions of the RADIATION 0.5% of the AIR KERMA RATE on the RADIATION BEAM AXIS in
FIELD at the distal end of the adjustable BEAM
the same plane as the measurements but without the lead
LIMITING DEVICE or therapeutic BEAM APPLICATOR
block
1.1 times the lateral dimensions of the
RADIATION 2% of the AIR KERMA RATE On the RADIATION BEAM AXIS in the
FIELD at the distal end of the adjustable BEAM
same plane as the measurements but without lead block
LIMITING DEVICE
or therapeutic BEAM APPLICATOR
Compliance shall be checked under the following conditions:
—
All measurements shall be made when the X -RAY GENERATOR is operated at NOMINAL
X-RAY TUBE VOLTAGE
and with the most attenuating FILTRATION specified.
—
Measurements shall be made with flat lead blocks that have the same shape as the
RADIATION FIELD
and the dimensions required in Table 102 so placed on the distal end
of each adjustable BEAM LIMITING DEVICE or therapeutic BEAM APPLICATOR
that the lead
forms a magnified but not displaced representation of the shape of the RADIATION FIELD.
Curved radiotranslucent distal ends of therapeutic BEAM APPLICATORS may be removed
for the purpose of measurements;
— Measurements shall be made at all places more than 20 mm from the edges of the lead
block in the plane of the surface of the lead block distal to the RADIATION SOURCE.
—
The lead blocks shall provide sufficient ATTENUATION to reduce the AIR KERMA RATE on
the RADIATION BEAM AXIS by a factor of at least 104.
— For adjustable BEAM LIMITING DEVICES
measurements shall be made at all specified
settings of the RADIATION FIELD.
— Measurements shall average AIR KERMA RATE
over an area of 10 cm2 in the plane of the
distal surface of the lead block with no principal dimensions greater than 4 cm.
29.1.104 Limitation of RADIATION from parts other than the
X-RA Y SOURCE ASSEMBLY
The AIR KERMA RATE
at any position 50 mm from the surface of any part of the therapeutic
X-RAY GENERATORS other than the
X-RAY SOURCE ASSEMBLY shall not exceed 0.02 mGy
(X =
2.3 mR) * in one hour.
* See Note to Table 101, Sub-clause 29.1.101.

601-2-8 © I E C 1987 — 41 —
Compliance shall be checked under the following conditions:
— Measurements shall be made with the X-RAY GENERATOR operated under conditions of use
that are possible within the specifications given in the ACCOMPANYING DOCUMENTS and are
the least favourable with regard to this requirement.
AIR KERMA RATE
— Measurements shall average the over an area of 10 cm2, with no principal
linear dimensions greater than 4 cm.
—
Measurements shall be made at the applicable distance.
29.1.105 Control of IRRADIATION
TREATMENT CONTROL PANEL outside TREATMENT ROOM
a)
Therapeutic X-RAY GENERATORS specified for operation at a NOMINAL X-RAY TUBE
VOLTAGE above 50 kV shall be so designed and constructed as to allow the TREATMENT
CONTROL PANEL to be located outside a room in which the X-RAY SOURCE ASSEMBLY is
located.
b) Distant indication
Therapeutic X-RAY GENERATORS shall be provided with connections for an indicating
device remote from the TREATMENT CONTROL PANEL arranged so that such a device can
give an indication while its HIGH VOLTAGE GENERATOR is in a condition corresponding to
the emission of a RADIATION BEAM. Technical details for the connection of a suitable device
shall be given in the ACCOMPANYING DOCUMENTS.
c) Distant control
Therapeutic X-RAY GENERATORS shall be provided with connections for a device that can
be positioned remote from the TREATMENT CONTROL PANEL, arranged so that such a device
can cause the X-RAY GENERATORS to interrupt emitting a RADIATION BEAM and can prevent
the X-RAY GENERATORS from starting to emit a RADIATION BEAM. Technical details for the
connection of a suitable device shall be given in the ACCOMPANYING DOCUMENTS.
d) Interruption
Therapeutic X-RAY GENERATORS shall be provided with means to allow the emission of
a RADIATION BEAM to be interrupted at any time by a positive action at the TREATMENT
CONTROL PANEL.
e) Initiation at TREATMENT CONTROL PANEL
Therapeutic X-RAY GENERATORS specified for operation at a NOMINAL X-RAY TUBE
VOLTAGE
above 50 kV shall be so designed and constructed that the emission of a
RADIATION BEAM can be initiated only by a positive action at the TREATMENT CONTROL
PANEL.
X-RAY SOURCE ASSEMBLIES designed and specified to be held by hand
29.1.106
a) Therapeutic X-RAY GENERATORS specified for operation with the X-RAY SOURCE ASSEMBLY
held by hand shall:
— have a NOMINAL X-RAY TUBE VOLTAGE not greater than 50 kV;
X-RAY SOURCE ASSEMBLY
— be so designed that the can alternatively be supported and
held by means other than by hand.

601-2-8 I E C 1987 — 43 —
©
PROTECTIVE CLOTH-
b) A statement shall be in the ACCOMPANYING DOCUMENTS advising that
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