ISO 7240-32:2025

International
Standard
ISO 7240-32
First edition
Fire detection and alarm systems —
2025-09
Part 32:
Non-resettable line-type heat
detectors
Systèmes de détection et d'alarme incendie —
Partie 32: Détecteurs de chaleur de type linéaire non-
réenclenchables
Reference number
© ISO 2025
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Published in Switzerland
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Contents Page
Foreword .vii
Introduction .viii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions and abbreviations . 1
3.1 Terms and definitions .2
3.2 Abbreviations .2
4 Requirements . 3
4.1 General .3
4.1.1 Conformance .3
4.1.2 NLTHD performance type .3
4.1.3 Heat response for Class A application .3
4.1.4 Environmental groups .3
4.2 Individual alarm indication .4
4.3 Signalling .4
4.4 Maximum ambient temperature.4
4.5 Connection of ancillary devices.4
4.6 Manufacturer's adjustments .4
4.7 Software .4
4.7.1 General .4
4.7.2 Software design .5
4.7.3 The storage of programs and data .5
4.8 Sensing element fault .5
4.9 On-site adjustment of response behaviour .5
4.10 Variation in supply parameters .5
4.11 Low voltage fault.5
4.12 Performance parameters under fire condition .6
4.13 Fire sensitivity for Class A application .6
4.14 Static response temperature test for Class A application .6
4.15 Dry heat (operational) for sensor control unit .6
4.16 Cold (operational) for sensing element .6
4.17 Cold (operational) for sensor control unit .6
4.18 Damp heat, steady-state (endurance) for sensor control unit and sensing element .6
4.19 Damp heat, cyclic (operational) for sensing element .6
4.20 Damp heat, cyclic (operational) for sensor control unit .6
4.21 Damp heat, steady-state (operational) for sensor control unit .6
4.22 Damp heat, cyclic (endurance) for sensor control unit and sensing element .6
4.23 Shock (operational) for sensor control unit .6
4.24 Impact (operational) for sensor control unit .7
4.25 Impact (operational) for sensing element .7
4.26 Vibration, sinusoidal (operational) for sensor control unit .7
4.27 Vibration, sinusoidal (operational) for sensing element .7
4.28 Vibration, sinusoidal (endurance) for sensor control unit .7
4.29 Vibration, sinusoidal (endurance) for sensing element .7
4.30 Sulphur dioxide (SO ) corrosion (endurance) for sensing element .7
4.31 Sulphur dioxide (SO ) corrosion (endurance) for sensor control unit .7
4.32 Electromagnetic compatibility (EMC), immunity (operational) .7
5 Test methods . 7
5.1 General .7
5.1.1 Atmospheric conditions for tests.7
5.1.2 Operating conditions for tests.8
5.1.3 Mounting arrangements .8
5.1.4 Tolerances .8

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5.1.5 Procedure for measurement of response temperature .8
5.1.6 Provision for tests .9
5.1.7 Test schedule .9
5.2 Individual alarm indication .11
5.3 Signalling .11
5.4 Maximum ambient temperature test (endurance) for sensing element .11
5.4.1 Objective of the test .11
5.4.2 Mounting of the sensing element .11
5.4.3 Test procedure. 12
5.4.4 Requirements . 12
5.5 Connection of ancillary devices. 12
5.6 Manufacturer's adjustments . 12
5.7 Requirements for software controlled detectors . 13
5.8 Sensing element fault . 13
5.8.1 Object of the test . 13
5.8.2 Test procedure. 13
5.8.3 Requirements . 13
5.9 On-site adjustment of response behaviour . 13
5.10 Variation in supply parameters . 13
5.10.1 Objective .
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