ISO/PAS 24499:2024
(Main)Method of test for burning velocity measurement of A2L flammable gases
Method of test for burning velocity measurement of A2L flammable gases
This document specifies a method of measuring the burning velocity (BV) of slowing burning refrigerants (
Méthode d'essai pour mesurer la vitesse d'inflammabilité des gaz inflammables A2L
General Information
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Specification
ISO/PAS 24499
First edition
Method of test for burning velocity
2024-05
measurement of A2L flammable gases
Méthode d'essai pour mesurer la vitesse d'inflammabilité des gaz
inflammables A2L
Reference number
© ISO 2024
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Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General test method . 2
4.1 General .2
4.2 Principle of the test method .2
5 Measurement parameters . 4
5.1 General .4
5.2 Flame propagation velocity .4
5.3 Flame front area .5
5.4 Cross-sectional area of the flame base .5
6 Test method . 5
6.1 General .5
6.2 Gas handling and mixtures preparation .6
6.3 The test tube .7
6.3.1 General .7
6.3.2 Dimensions .8
6.3.3 Position .9
6.3.4 Tube ends .9
6.3.5 Interchangeable damping orifices .9
6.3.6 Flame quenching .10
6.3.7 Tube glass type .10
6.3.8 Tube purging with test mixture .10
6.3.9 Tube etching .10
6.4 Ignition .11
6.4.1 General .11
6.4.2 Ignition type .11
6.4.3 Positioning .11
6.4.4 Electrodes .11
6.4.5 Power supply . .11
6.4.6 Ignition time .11
6.5 Flame front visualization . 12
6.5.1 General . 12
6.5.2 Luminous zone and direct photography . 12
6.5.3 Flame emission spectra . 12
6.5.4 Acquisition camera . 12
6.5.5 Exposure Time . 13
6.5.6 Positioning . 13
6.5.7 Scaling and optical distortion. 13
6.5.8 Resolution of the flame images .14
6.6 Purge, exhaust and gas treatment systems .14
6.7 Test temperature setting . 15
6.8 Experimental protocol for mixtures prepared using partial pressure technique.16
7 Evaluation and expression of results . .16
7.1 General .16
7.2 Uncertainty .17
7.2.1 Uncertainty in the burning velocity .17
7.2.2 Uncertainty estimation of concentrations .17
8 Safety precautions. 17
iii
9 Overview on flame shape, propagation regimes and stability .18
9.1 Flame shape.18
9.2 Flame propagation regimes .19
9.3 Flame stability in tubes . 20
9.4 Observations of flames in tubes .21
9.5 Flame quenching in circular tubes .21
9.6 Flame propagation velocity and tube diameter . 22
9.7 Flame area calculation . 22
Bibliography .24
iv
Foreword
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rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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this may not rep
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