IEC 62598:2011

IEC 62598 ®
Edition 1.0 2011-03
INTERNATIONAL
STANDARD
Nuclear instrumentation – Constructional requirements and classification of
radiometric gauges
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IEC 62598 ®
Edition 1.0 2011-03
INTERNATIONAL
STANDARD
Nuclear instrumentation – Constructional requirements and classification of
radiometric gauges
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
T
ICS 27.120 ISBN 978-2-88912-421-3

– 2 – 62598  IEC:2011(E)
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope and object . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Classification of radiometric gauge types . 9
4.1 Category A: Radiometric gauges with restricted beam . 9
4.2 Category B: Radiometric gauges with omnidirectional beam . 11
4.3 Category C: Stand alone source housings for fixed radiometric gauges . 11
4.4 Dose rate classes . 12
4.5 Temperature class . 12
5 General requirements . 13
5.1 Measuring gap . 13
5.2 Source holder . 13
5.3 Source housing . 13
5.4 Alignment of the useful beam . 13
5.5 Other requirements . 13
6 Protection against ionizing radiation . 14
6.1 General requirements . 14
6.2 Requirements for Category A gauges . 14
6.3 Requirements for Category B gauges . 14
6.4 Requirements for Category C stand alone source housings . 14
6.5 Resistance of the source housing in case of fire . 15
6.6 Detector housing . 15
6.7 Measuring head . 15
7 Other safety devices . 15
7.1 General . 15
7.2 Protection against non-authorized use . 15
7.3 Indication of the shutter position . 16
7.4 Additional warning device . 16
8 Determination of the dose equivalent rate . 16
8.1 General . 16
8.2 Dose equivalent rate measurements in the case of closed shutters . 18
8.3 Dose equivalent rate measurements in the case of open shutters . 18
8.4 Procedure for dose equivalent rate measurements . 18
8.5 Determining the relevant values of the dose equivalent rate . 19
9 Test methods . 19
9.1 General . 19
9.2 Temperature cycle test on the shutters and the source holder . 19
9.2.1 Requirements . 19
9.2.2 Procedure . 19
9.3 Test for checking the resistance of the shutter, the source holder and the
source container in case of fire . 20
9.3.1 Requirements . 20
9.3.2 Procedure . 20

62598  IEC:2011(E) – 3 –
9.4 Test for checking the mechanical resistance of the shutter and the source
holder . 20
9.4.1 Requirements . 20
9.4.2 Procedure . 21
10 System classification coding and labelling . 21
10.1 Classification code . 21
10.2 Labelling . 22
11 Accompanying documents . 22
Annex A (informative) Guidelines for the installation of radiometric gauges . 23

Figure 1 – Schematic arrangement of Category A gauges . 10
Figure 2 – Schematic arrangement of Category B gauges . 11
Figure 3 – Category C stand alone source housing for fixed level or density gauges . 11
Figure 4 – Schematic representation of isodistance gauging faces in the case of
thickness gauges . 17
Figure 5 – Schematic representation of isodistance gauging faces in the case of level
and density gauges and back-scatter gauges . 17
Figure 6 – Schematic representation of isodistance gauging faces in the case of stand
alone source housings . 18
Figure A.1 – Examples of protection methods and principles . 24

Table 1 – Dose rate classes . 12
Table 2 – Temperature classes . 12
Table 3 – Fire resistance classes . 15

– 4 – 62598  IEC:2011(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NUCLEAR INSTRUMENTATION –
CONSTRUCTIONAL REQUIREMENTS
AND CLASSIFICATION OF RADIOMETRIC GAUGES

FOREWORD
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International Standard IEC 62598 has been prepared by IEC technical committee 45: Nuclear
instrumentation.
This standard cancels and replaces the second edition of IEC 60405, issued in 2003. It
constitutes a technical revision (see Introduction).
The text of this standard is based on the following documents:
FDIS Report on voting
45/718/FDIS 45/721/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.

62598  IEC:2011(E) – 5 –
The committe
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