ISO 24460:2023

Measurement of fluid flow rate in closed conduits — Radioactive tracer methods

This document defines the measurement of single phase fluid flow rate in closed conduits using radioactive tracer methods.

Mesure du débit des fluides dans des conduites fermées — Méthodes par traceur radioactif

Le présent document définit le mesurage du débit d’un fluide monophasique dans des conduites fermées à l’aide de méthodes par traceur radioactif.

General Information

• Status: Published
• Publication Date: 19-Sep-2023
• ICS: 17.120.10 - Flow in closed conduits
• Technical Committee: ISO/TC 30/SC 5 - Velocity and mass methods
• Drafting Committee: ISO/TC 30/SC 5/WG 7 - Tracer methods
• Current Stage: 6060 - International Standard published
• Start Date: 20-Sep-2023
• Due Date: 17-Jul-2023
• Completion Date: 20-Sep-2023

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 24460
First edition
2023-09
Measurement of fluid flow rate in
closed conduits — Radioactive tracer
methods
Mesure du débit des fluides dans des conduites fermées — Méthodes
par traceur radioactif
Reference number
© ISO 2023
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ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principles of radioactive tracer methods . 1
4.1 General . 1
4.2 Transit time method . 1
4.2.1 Principle . 1
4.2.2 Special recommendation for the transit time method . 3
4.2.3 Advantages of transit time method . 3
4.3 Constant rate injection method . 4
4.3.1 Principle . 4
4.3.2 Duration of injection . 4
4.3.3 Advantage of the constant rate injection method . 5
4.4 Integration method . 6
4.4.1 Principle . 6
4.4.2 Advantages of the integration method . 7
5 Choice of radioactive tracer .7
5.1 General . 7
5.1.1 Requirements . 7
5.1.2 Radioactive tracers . 7
5.2 Advantages of radioactive tracers . 8
5.3 Particular advantages of radionuclide generators . 8
5.4 Selection of radioactive tracer . 8
5.4.1 Type of emitted radiations . 8
5.4.2 Half-life . 9
6 Choice of adequate mixing length.9
6.1 General . 9
6.2 Consideration on the mixing length . 9
6.2.1 General . 9
6.2.2 Examples of injection techniques for reducing mixing length . 10
7 Detection of radioactive tracer .11
7.1 General . 11
7.2 Gamma radiation detector . 11
7.3 Detector arrangement . 11
7.4 Data acquisition system .12
8 Procedures for applying radioactive tracer methods .12
8.1 Transit time method . 12
8.1.1 Location of injection cross-section .12
8.1.2 Pulse injection of radioactive tracer . 13
8.1.3 Estimation of the activity to be injected . 14
8.1.4 Choice of measuring length . 15
8.1.5 Calculation of transit time . 15
8.2 Constant rate injection method . 16
8.2.1 Preparation of the radioactive tracer to be injected . 16
8.2.2 Injection of the radioactive tracer . 17
8.2.3 Measurement of injection rate . 17
8.3 Integration method . 17
9 Uncertainty .17
9.1 General . 17
iii
9.1.1 E valuation of uncertainty . 17
9.1.2 Procedures for evaluating the uncertainty of a measured flow rate . 18
9.1.3 Uncertainty propagation formula . 18
9.2 Uncertainty of flow rate measured using the transit time method . 19
9.3 Uncertainty of flow rate measured using the constant rate injection method .20
9.4 Uncertainty of flow rate measured using the integration method .22
Annex A (informative) Calculation of transit time and its standard uncertainty .25
Annex B (informative) Radiation dose considerations .31
Bibliography .32
iv
Foreword
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This document was prepared by Technical Committee ISO/TC 30, Measurement of fluid flow in closed
conduits, Subcommittee SC 5, Velocity and mass methods.
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v
Introduction
The accurate knowledge of fluid flow rates (liquid and gas) in industrial systems is an essential
requirement of processing industries. The fluid flow rate measurement is usually needed for various
reasons i.e. calibration of installed flow meters, fluid balance, measurement of efficacy of pumps or
tur
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