IEC 63506:2026

IEC 63506 ®
Edition 1.0 2026-06
INTERNATIONAL
STANDARD
Calibration of the prompt fission neutron logging tools

ICS 27.120.01; 17.240 ISBN 978-2-8327-1284-9

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CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Working principle . 5
5 Preparation . 5
6 Control of measuring instruments . 6
6.1 Calibration conditions . 6
6.1.1 Calibration equipment. 6
6.1.2 Environment condition . 6
6.2 Calibration items . 6
6.3 Safety requirements . 6
6.4 Calibration method. 6
6.4.1 Uranium concentration sensitivity . 6
6.4.2 Indication error . 7
6.4.3 Nonlinearity . 8
6.4.4 Repeatability . 9
6.4.5 Short-term stability . 9
6.5 Calibration cycle . 9
Bibliography . 10

Table 1 – Main technical specifications of various pits . 6
Table 2 – Calibration items . 6

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Calibration of the prompt fission neutron logging tools
FOREWORD
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IEC 63506 has been prepared by IEC technical committee 45: Nuclear instrumentation. It is an
International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
45/1044/FDIS 45/1052/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
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– withdrawn, or
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1 Scope
This document specifies the calibration method of prompt fission neutron logging tools.
This document applies to the calibration of prompt fission neutron logging tools for uranium
exploration and mining.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-395, International Electrotechnical Vocabulary (IEV) - Part 395: Nuclear
instrumentation - Physical phenomena, basic concepts, instruments, systems, equipment and
detectors
IEC 62598, Nuclear instrumentation - Constructional requirements and classification of
radiometric gauges
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-395 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online br
...