IEC 60068-2-30:2025

Environmental testing - Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)

IEC 60068-2-30:2025 specifies a test procedure to determine the suitability of components, equipment, or other articles for use, transportation, and storage under conditions of high humidity combined with cyclic temperature changes and, in general, producing condensation on the surface of the specimen. This test method can also be used to validate the packaging of specimen for transportation and storage.
This fourth edition cancels and replaces the third edition published in 2005. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) revision of the requirements for the test chamber;
b) change of the temperature tolerances of the test to limits;
c) updating of the figures for clarification purposes;
d) revision of the limits of the temperature and relative humidity during conditioning;
e) revision of the intermediate measurements;
f) revision of standardized requirements for the test report.

Essais d'environnement - Partie 2-30: Essais - Essai Db: Essai cyclique chaleur de humide (cycle de 12 h + 12 h)

L'IEC 60068-2-30:2025 spécifie une procédure d'essai pour déterminer l'aptitude des composants, des équipements ou d'autres articles destinés à être utilisés, transportés ou stockés dans des conditions d'humidité élevée combinées à des variations cycliques de température et généralement à la formation de condensation à la surface des spécimens. Cette méthode d'essai peut également être appliquée pour valider l'emballage du spécimen en vue du transport et du stockage.
Cette quatrième édition annule et remplace la troisième édition parue en 2005. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) révision des exigences relatives à la chambre d'essai;
b) modification des tolérances de température de l'essai aux limites;
c) mise à jour des figures à des fins de clarification;
d) révision des limites de température et d'humidité relative pendant l'épreuve;
e) révision des mesurages intermédiaires;
f) révision des exigences normatives relatives au rapport d'essai;

General Information

• Status: Published
• Publication Date: 06-Aug-2025
• ICS: 19.040 - Environmental testing
• Technical Committee: TC 104 - Environmental conditions, classification and methods of test
• Drafting Committee: MT 16 - TC 104/MT 16
• Current Stage: PPUB - Publication issued
• Start Date: 07-Aug-2025
• Completion Date: 29-Aug-2025

Relations

• Revises: IEC 60068-2-30:2005 - Environmental testing - Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)
• Effective Date: 05-Sep-2023

Overview

IEC 60068-2-30:2025 - "Environmental testing - Test Db: Damp heat, cyclic (12 h + 12 h cycle)" is the 4th edition (2025) international standard that defines a cyclic damp‑heat test procedure to assess the suitability of components, equipment and other articles for use, transportation and storage when exposed to high humidity combined with cyclic temperature changes that generally produce surface condensation. The procedure also supports packaging validation for transport and storage. This edition updates chamber requirements, temperature tolerances, conditioning limits, intermediate measurements and standardized test‑report content.

Key topics and technical requirements

• Test purpose: Determine resistance to humid, cyclic thermal conditions that produce condensation on specimen surfaces.
• Cycle format: 12 h + 12 h cyclic damp‑heat sequence (two variants differ in the cooling period).
• Severities (Methods I–IV): Combination of variant, high conditioning temperature and number of cycles defines severity. Typical ranges from the standard:
  • Variant 1: High conditioning 38 °C–42 °C (Methods I, III - cycles 2, 6, 12, 21, 56)
  • Variant 1: High conditioning 53 °C–57 °C (Methods II, IV - cycles 1, 2, 6)
• Test chamber requirements: Ability to vary temperature cyclically (including 22 °C–28 °C low range), control relative humidity to Variant 1 or 2 limits, ensure uniform conditions, avoid radiant heating of specimens, remote humidification (no direct droplets), continuous drainage and water quality per IEC 60068-2-67.
• Procedure elements: Initial measurements, preconditioning, the cyclic test, intermediate measurements, recovery, final measurements and required content for the test report. The standard generally excludes continuously energized specimens (except in exceptional cases).
• Documentation changes: Clearer figures, revised tolerances now expressed as limits, and updated reporting requirements.

Practical applications

• Qualification and reliability testing of electronic components, assemblies and equipment for humid environments.
• Validation of packaging for transportation and storage under humid/condensing conditions.
• Environmental stress screening in industries such as consumer electronics, industrial controls, automotive, aerospace and telecommunications (where humidity and condensation can cause corrosion, short circuits or performance degradation).

Who should use this standard

• Environmental test labs and chamber manufacturers
• Reliability and qualification engineers
• Design and test engineers for electronic hardware and packaged goods
• Quality assurance and compliance teams preparing test reports and product specifications

Related standards

• IEC 60068-1 - Environmental testing: General and guidance
• IEC 60068-2-67 - Damp heat, steady state (water quality/humidification references)

Keywords: IEC 60068-2-30, damp heat cyclic, environmental testing, humidity testing, temperature cycling, test Db, condensation testing, packaging validation, test chamber requirements.

Standards Content (Sample)

IEC 60068-2-30 ®
Edition 4.0 2025-08
INTERNATIONAL
STANDARD
Environmental testing -
Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)
ICS 19.040  ISBN 978-2-8327-0616-9

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CONTENTS
FOREWORD. 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General description . 5
5 Description of test chamber . 6
6 Severities . 6
7 Testing procedure . 6
7.1 General . 6
7.2 Initial measurements . 7
7.3 Preconditioning . 7
7.4 Test cycle . 8
7.5 Intermediate measurements . 14
8 Recovery . 14
9 Final measurements . 15
10 Information to be given in the relevant specification . 16
11 Information to be given in the test report . 16
Annex A (informative) Selection of variant for the cooling period – Guidance . 18
Annex B (normative) Supporting documentation for temperature and humidity limits in
the test sequences . 19
B.1 General . 19
B.2 Preconditioning . 19
B.3 Variant 1 . 20
B.4 Variant 2 . 20
B.5 Recovery . 21
Annex C (informative) Supporting documentation for programming the set value . 22
C.1 General . 22
C.2 Preconditioning . 22
C.3 Variant 1 . 22
C.4 Variant 2 . 23
C.5 Recovery . 23
Bibliography . 24

Figure 1 – Test Db – Preconditioning period . 8
Figure 2 – Test Db – Test cycle – Variant 1, Method I . 10
Figure 3 – Test Db – Test cycle – Variant 1, Method II . 11
Figure 4 – Test Db – Test cycle – Variant 2, Method III . 12
Figure 5 – Test Db – Test cycle – Variant 2, Method IV . 13
Figure 6 – Test Db – Recovery at controlled conditions . 15

Table 1 – Severities of Test Db . 6
Table B.1 – Limits of relative humidity during preconditioning . 19
Table B.2 – Temperature limits during preconditioning . 19
Table B.3 – Limits of relative humidity and temperature during Variant 1 . 20
Table B.4 – Limits of relative humidity and temperature during Variant 2 . 20
Table B.5 – Limits of relative humidity during recovery . 21
Table B.6 – Temperature limits during recovery . 21
Table C.1 – Example of programming of the preconditioning . 22
Table C.2 – Example of programming of the relative humidity and temperature
(Variant 1) . 22
Table C.3 – Example of programming of the relative humidity and temperature
(Variant 2) . 23
Table C.4 – Example of programming of the recovery procedure . 23

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Environmental testing -
Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)

FOREWORD
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shall not be held responsible for identifying any or all such patent rights.
IEC 60068-2-30 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of the requirements for the test chamber;
b) change of the temperature tolerances of the test to limits;
c) updating of the figures for clarification purposes;
d) revision of the limits of the temperature and relative humidity during conditioning;
e) revision of the intermediate measurements;
f) revision of standardized requirements for the test report.
The text of this International Standard is based on the following documents:
Draft Report on voting
104/1111/FDIS 104/1125/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.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all the parts of the IEC 60068 series, under the general title Environmental testing, can
be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
1 Scope
This part of IEC 60068 specifies a test procedure to determine the suitability of components,
equipment, or other articles for use, transportation, and storage under conditions of high
humidity combined with cyclic temperature changes and, in general, producing condensation
on the surface of the specimen. This test method can also be used to validate the packaging of
specimen for transportation and storage.
This document does only in exceptional cases apply to specimens that are energized throughout
the test.
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 60068-1, Environmental testing - Part 1: General and guidance
IEC 60068-2-67, Environmental testing - Part 2-67: Tests - Test Cy: Damp heat, steady state,
accelerated test primarily intended for components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-1 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 browsing platform: available at https://www.iso.org/obp
4 General description
This test comprises one or more temperature cycles in which the relative humidity is maintained
at a high level.
Two variants of the cycle are given which are identical except for the cooling period; during this
part of the cycle, Variant 2 allows wider limits of relative humidity and the temperature change
rate.
The conditioning temperature and the number of cycles (see Clause 6) determine the test
severity.
The preconditioning phase is illustrated in Figure 1, the test procedure in Figure 2 to Figure 5
and the recovery procedure in Figure 6.
NOTE For small, low mass specimens, it can be difficult to produce condensation on the surface of the specimen
using this procedure; considering an alternative test such as Test Z/AD (IEC 60068-2-38) can be helpful.
5 Description of test chamber
The test chamber shall be so constructed that:
a) the temperature in the working space can be varied cyclically between 22 °C to 28 °C as
well as the appropriate high conditioning temperature in a period specified in 7.4 as well as
Figure 2 to Figure 5, as applicable;
b) the relative humidity in the working space can be maintained within the limits of Variant 1
or Variant 2, or both, as given in 7.4 as well as in Figure 2 to Figure 5, as applicable;
c) the conditions prevailing at any point in the working space are uniform and are as similar as
possible to those prevailing in the immediate vicinity of suitably located temperature- and
humidity-sensing devices; the air in the chamber will therefore be continuously stirred at a
rate necessary to maintain the specified conditions of temperature and humidity;
d) the specimen under test is not subjected to radiant heat from the chamber conditioning
processes;
e) the water used for the chamber humidity system complies with the limits given in
IEC 60068-2-67;
f) any water is continuously drained from the chamber and not used again unless it has been
re-purified;
g) the materials used in the construction do not cause any significant corrosion of the
specimen, or degradation of the quality of the humidifying water;
h) injected moisture, when applicable, is not directly applied to the specimen but injected
remotely from the specimen. Precautions shall be taken to ensure that no droplet of injected
water deposits on the specimens.
Precautions should be taken to ensure that no condensed water from the walls and roof of the
test chamber can fall on the specimen. The specimen should not significantly impede the air
flow.
6 Severities
The combination of the test variant, the conditioning temperature and the number of cycles
define the severity of this test.
The severity shall be chosen from the methods given in Table 1:
Table 1 – Severities of Test Db
Method Variant High conditioning temperature Number of cycles
I 38 °C to 42 °C 2, 6, 12, 21, 56
II 53 °C to 57 °C 1, 2, 6
III 38 °C to 42 °C 2, 6, 12, 21, 56
IV 53 °C to 57 °C 1, 2, 6
7 Testing procedure
7.1 General
The specimens shall be introduced into the chamber either in the unpacked, switched-off, ready-
for-use state, or as otherwise specified in the relevant specification.
This document does not apply to specimens that are energized during the complete test, except
in exceptional cases. Specimens can be energized during the constant phases of the tests.
Measurements on energized specimens are typically carried out during constant phases of the
test unless specified otherwise (see 7.5).
Where no specific mounting is specified, the thermal conduction of the mounting shall be low,
so that for all practical purposes the specimen is thermally isolated.
The dimensions, properties or electrical loading of the specimens under test shall not
appreciably influence conditions within the test chamber.
The temperature and relative humidity limits given in this docume
...

IEC 60068-2-30 ®
Edition 4.0 2025-08
NORME
INTERNATIONALE
Essais d'environnement -
Partie 2-30: Essais - Essai Db: Essai cyclique chaleur de humide (cycle de 12 h +
12 h)
ICS 19.040  ISBN 978-2-8327-0616-9

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SOMMAIRE
AVANT-PROPOS . 3
1 Domaine d'application . 5
2 Références normatives . 5
3 Termes et définitions . 5
4 Description générale . 5
5 Description de la chambre d'essai . 6
6 Sévérités . 6
7 Procédure d'essai . 6
7.1 Généralités . 6
7.2 Mesurages initiaux . 7
7.3 Préconditionnement . 7
7.4 Cycle d'essai . 9
7.5 Mesurages intermédiaires . 14
8 Reprise . 14
9 Mesurages finaux . 15
10 Renseignements à fournir dans la spécification applicable . 16
11 Renseignements à fournir dans le rapport d'essai . 16
Annexe A (informative) Sélection de la variante pour la période de refroidissement –
Recommandations . 18
Annexe B (normative) Documentation d'accompagnement relative aux limites de
température et d'humidité dans les séquences d'essai . 19
B.1 Généralités . 19
B.2 Préconditionnement . 19
B.3 Variante 1 . 20
B.4 Variante 2 . 20
B.5 Reprise . 21
Annexe C (informative) Documentation d'accompagnement pour l'établissement de la
valeur de consigne . 22
C.1 Généralités . 22
C.2 Préconditionnement . 22
C.3 Variante 1 . 22
C.4 Variante 2 . 23
C.5 Reprise . 23
Bibliographie . 24

Figure 1 – Essai Db – Période de préconditionnement . 8
Figure 2 – Essai Db – Cycle d'essai – Variante 1, Méthode I . 10
Figure 3 – Essai Db – Cycle d'essai – Variante 1, Méthode II . 11
Figure 4 – Essai Db – Cycle d'essai – Variante 2, Méthode III . 12
Figure 5 – Essai Db – Cycle d'essai – Variante 2, Méthode IV . 13
Figure 6 – Essai Db – Reprise sous conditions contrôlées . 15

Tableau 1 – Sévérités de l'Essai Db . 6
Tableau B.1 – Limites d'humidité relative pendant le préconditionnement . 19
Tableau B.2 – Limites de température pendant le préconditionnement . 19
Tableau B.3 – Limites d'humidité relative et de température pendant la Variante 1 . 20
Tableau B.4 – Limites d'humidité relative et de température pendant la Variante 2 . 20
Tableau B.5 – Limites d'humidité relative pendant la reprise . 21
Tableau B.6 – Limites de température pendant la reprise . 21
Tableau C.1 – Exemple de planification du préconditionnement . 22
Tableau C.2 – Exemple de planification de l'humidité relative et de la température
(Variante 1) . 22
Tableau C.3 – Exemple de planification de l'humidité relative et de la température

(Variante 2) . 23
Tableau C.4 – Exemple de planification de la procédure de reprise . 23

COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
Essais d'environnement -
Partie 2-30: Essais - Essai Db: Essai cyclique de chaleur humide
(cycle de 12 h + 12 h)
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L'IEC ne saurait être tenue pour responsable de ne pas avoir identifié de tels droits de brevets.
L'IEC 60068-2-30 a été établie par le comité d'études 104 de l'IEC: Conditions, classification et
essais d'environnement. Il s'agit d'une Norme internationale.
Cette quatrième édition annule et remplace la troisième édition parue en 2005. Cette édition
constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition
précédente:
a) révision des exigences relatives à la chambre d'essai;
b) modification des tolérances de température de l'essai aux limites;
c) mise à jour des figures à des fins de clarification;
d) révision des limites de température et d'humidité relative pendant l'épreuve;
e) révision des mesurages intermédiaires;
f) révision des exigences normatives relatives au rapport d'essai;
Le texte de cette Norme internationale est issu des documents suivants:
Projet Rapport de vote
104/1111/FDIS 104/1125/RVD
Le rapport de vote indiqué dans le tableau ci-dessus donne toute information sur le vote ayant
abouti à son approbation.
La langue employée pour l'élaboration de cette Norme internationale est l'anglais.
Ce document a été rédigé selon les Directives ISO/IEC, Partie 2, il a été développé selon les
Directives ISO/IEC, Partie 1 et les Directives ISO/IEC, Supplément IEC, disponibles sous
www.iec.ch/members_experts/refdocs. Les principaux types de documents développés par
l'IEC sont décrits plus en détail sous www.iec.ch/publications.
Une liste de toutes les parties de la série IEC 60068, publiées sous le titre général Essais
d'environnement, se trouve sur le site web de l'IEC.
Le comité a décidé que le contenu de ce document ne sera pas modifié avant la date de stabilité
indiquée sur le site web de l'IEC sous webstore.iec.ch dans les données relatives au document
recherché. À cette date, le document sera
• reconduit,
• supprimé, ou
• révisé.
1 Domaine d'application
La présente partie de l'IEC 60068 spécifie une procédure d'essai pour déterminer l'aptitude des
composants, des équipements ou d'autres articles destinés à être utilisés, transportés ou
stockés dans des conditions d'humidité élevée combinées à des variations cycliques de
température et généralement à la formation de condensation à la surface des spécimens. Cette
méthode d'essai peut également être appliquée pour valider l'emballage du spécimen en vue
du transport et du stockage.
Le présent document ne s'applique qu'exceptionnellement aux spécimens sous tension tout au
long de l'essai.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu'ils constituent, pour tout ou partie
de leur contenu, des exigences du présent document. Pour les références datées, seule
l'édition citée s'applique. Pour les références non datées, la dernière édition du document de
référence s'applique (y compris les éventuels amendements).
IEC 60068-1, Essais d'environnement - Partie 1: Généralités et lignes directrices
IEC 60068-2-67, Essais d'environnement - Partie 2-67: Essais - Essai Cy: Essai continu de
chaleur humide, essai accéléré applicable en premier lieu aux composants
3 Termes et définitions
Pour les besoins du présent document, les termes et les définitions de l'IEC 60068-1
s'appliquent.
L'ISO et l'IEC tiennent à jour des bases de données terminologiques destinées à être utilisées
en normalisation, consultables aux adresses suivantes:
• IEC Electropedia: disponible à l'adresse https://www.electropedia.org/
• ISO Online browsing platform: disponible à l'adresse https://www.iso.org/obp
4 Description générale
Cet essai comporte un ou plusieurs cycles de température avec une humidité relative maintenue
à un niveau élevé.
Deux variantes du cycle sont données; elles sont identiques à l'exception de la période de
refroidissement; pendant cette partie du cycle, la Variante 2 tolère des limites plus grandes sur
l'humidité relative et la vitesse de variation de la température.
La sévérité de l'essai est déterminée par la température d'épreuve et par le nombre de cycles
(voir l'Article 6).
La Figure 1 représente la phase de préconditionnement, les Figures 2 à 5 représentent la
procédure d'essai, tandis que la Figure 6 représente la procédure de reprise.
NOTE Pour les spécimens de petite taille et de faible masse, il peut être difficile de produire de la condensation à
la surface du spécimen soumis à cette procédure; il peut être utile d'envisager un essai alternatif tel que l'Essai Z/AD
(IEC 60068-2-38).
5 Description de la chambre d'essai
La chambre d'essai doit être construite de façon telle que:
a) la température dans l'espace de travail puisse varier cycliquement entre 22 °C et 28 °C et
la température d'épreuve haute appropriée, spécifiée en 7.4 et dans les Figures 2 à 5, selon
le cas;
b) l'humidité relative dans l'espace de travail puisse être maintenue dans les limites
correspondant à la Variante 1 ou à la Variante 2, données en 7.4 et dans les Figures 2 à 5,
selon le cas;
c) les conditions qui règnent en tout point de l'espace de travail soient homogènes et aussi
proches que possible de celles existant au voisinage immédiat des dispositifs de mesure de
température et d'humidité relative, disposés de façon convenable; l'air dans la chambre est
donc constamment brassé à la vitesse nécessaire pour maintenir les conditions spécifiées
de température et d'humidité;
d) le spécimen en essai ne soit pas soumis aux rayonnements thermiques dus aux processus
de conditionnement de la chambre;
e) l'eau utilisée par le système d'humidité de la chambre soit conforme aux limites données
dans l'IEC 60068-2-67;
f) l'eau de condensation soit constamment drainée en dehors de la chambre et ne soit pas
réutilisée, à moins d'avoir été purifiée à nouveau;
g) les matériaux utilisés dans la construction n'entraînent pas une corrosion significative du
spécimen ou la dégradation de la qualité de l'eau d'humidification;
h) l'injection d'humidité, le cas échéant, ne soit pas directement dirigée sur le spécimen, mais
soit effectuée à distance de ce dernier. Des précautions doivent être prises pour s'assurer
qu'aucune gouttelette d'eau injectée ne se dépose sur les spécimens.
Il convient de prendre des précautions pour s'assurer que l'eau obtenue par condensation sur
les parois et le toit de la chambre d'essai ne puisse pas tomber sur le spécimen. Il convient que
le spécimen ne gêne pas de façon significative la circulation de l'air.
6 Sévérités
La sévérité de l'essai est définie par la variante d'essai, la température d'épreuve et le nombre
de cycles.
La sévérité doit être choisie parmi les méthodes du Tableau 1:
Tableau 1 – Sévérités de l'Essai Db
Méthode Variante Température d'épreuve haute Nombre de cycles
I 38 °C à 42 °C 2, 6, 12, 21, 56
II 53 °C à 57 °C 1, 2, 6
III 38 °C à 42 °C 2, 6, 12, 21, 56
IV 53 °C à 57 °C 1, 2, 6
7 Procédure d'essai
7.1 Généralités
Les spécimens doivent être introduits dans la chambre soit non emballés, sans application de
tension, prêts à fonctionner, soit dans d'autres conditions spécifiées dans la spécification
applicable.
Le présent document ne s'applique pas aux spécimens sous tension tout au long de l'essai,
sauf cas exceptionnels. Les spécimens peuvent être mis sous tension durant les phases
constantes de l'essai. Les mesurages sur spécimens sous tension sont généralement réalisés
pendant les phases constantes de l'essai, sauf spécification contraire (voir 7.5).
Lorsqu'aucun montage spécial n'est spécifié, la conduction thermique du montage doit être
faible afin d'isoler thermiquement le spécimen à des fins pratiques.
Les dimensions, les caractéristiques ou la dissipation des spécimens en essai ne doivent pas
influencer de façon appréciable les conditions régnant à l'intérieur de la chambre d'essai.
Les limites de température et d'humidité relative données dans le présent document sont
destinées à prendre en compte les erreurs de mesure, les variations lentes de température et
les variations de température de l'espace de travail.
NOTE 1 Pour plus d'informations sur l'espace de travail, voir l'IEC 60068-3-6.
La température et l'humidité relative font référence au capteur de régulation de la chambre
d'essai, sauf
...

IEC 60068-2-30 ®
Edition 4.0 2025-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Environmental testing -
Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)

Essais d'environnement -
Partie 2-30: Essais - Essai Db: Essai cyclique chaleur de humide (cycle de 12 h +
12 h)
ICS 19.040  ISBN 978-2-8327-0616-9

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CONTENTS
FOREWORD. 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General description . 5
5 Description of test chamber . 6
6 Severities . 6
7 Testing procedure . 6
7.1 General . 6
7.2 Initial measurements . 7
7.3 Preconditioning . 7
7.4 Test cycle . 8
7.5 Intermediate measurements . 14
8 Recovery . 14
9 Final measurements . 15
10 Information to be given in the relevant specification . 16
11 Information to be given in the test report . 16
Annex A (informative) Selection of variant for the cooling period – Guidance . 18
Annex B (normative) Supporting documentation for temperature and humidity limits in
the test sequences . 19
B.1 General . 19
B.2 Preconditioning . 19
B.3 Variant 1 . 20
B.4 Variant 2 . 20
B.5 Recovery . 21
Annex C (informative) Supporting documentation for programming the set value . 22
C.1 General . 22
C.2 Preconditioning . 22
C.3 Variant 1 . 22
C.4 Variant 2 . 23
C.5 Recovery . 23
Bibliography . 24

Figure 1 – Test Db – Preconditioning period . 8
Figure 2 – Test Db – Test cycle – Variant 1, Method I . 10
Figure 3 – Test Db – Test cycle – Variant 1, Method II . 11
Figure 4 – Test Db – Test cycle – Variant 2, Method III . 12
Figure 5 – Test Db – Test cycle – Variant 2, Method IV . 13
Figure 6 – Test Db – Recovery at controlled conditions . 15

Table 1 – Severities of Test Db . 6
Table B.1 – Limits of relative humidity during preconditioning . 19
Table B.2 – Temperature limits during preconditioning . 19
Table B.3 – Limits of relative humidity and temperature during Variant 1 . 20
Table B.4 – Limits of relative humidity and temperature during Variant 2 . 20
Table B.5 – Limits of relative humidity during recovery . 21
Table B.6 – Temperature limits during recovery . 21
Table C.1 – Example of programming of the preconditioning . 22
Table C.2 – Example of programming of the relative humidity and temperature
(Variant 1) . 22
Table C.3 – Example of programming of the relative humidity and temperature
(Variant 2) . 23
Table C.4 – Example of programming of the recovery procedure . 23

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Environmental testing -
Part 2-30: Tests - Test Db: Damp heat, cyclic (12 h + 12 h cycle)

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60068-2-30 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of the requirements for the test chamber;
b) change of the temperature tolerances of the test to limits;
c) updating of the figures for clarification purposes;
d) revision of the limits of the temperature and relative humidity during conditioning;
e) revision of the intermediate measurements;
f) revision of standardized requirements for the test report.
The text of this International Standard is based on the following documents:
Draft Report on voting
104/1111/FDIS 104/1125/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.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all the parts of the IEC 60068 series, under the general title Environmental testing, can
be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
1 Scope
This part of IEC 60068 specifies a test procedure to determine the suitability of components,
equipment, or other articles for use, transportation, and storage under conditions of high
humidity combined with cyclic temperature changes and, in general, producing condensation
on the surface of the specimen. This test method can also be used to validate the packaging of
specimen for transportation and storage.
This document does only in exceptional cases apply to specimens that are energized throughout
the test.
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 60068-1, Environmental testing - Part 1: General and guidance
IEC 60068-2-67, Environmental testing - Part 2-67: Tests - Test Cy: Damp heat, steady state,
accelerated test primarily intended for components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-1 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 browsing platform: available at https://www.iso.org/obp
4 General description
This test comprises one or more temperature cycles in which the relative humidity is maintained
at a high level.
Two variants of the cycle are given which are identical except for the cooling period; during this
part of the cycle, Variant 2 allows wider limits of relative humidity and the temperature change
rate.
The conditioning temperature and the number of cycles (see Clause 6) determine the test
severity.
The preconditioning phase is illustrated in Figure 1, the test procedure in Figure 2 to Figure 5
and the recovery procedure in Figure 6.
NOTE For small, low mass specimens, it can be difficult to produce condensation on the surface of the specimen
using this procedure; considering an alternative test such as Test Z/AD (IEC 60068-2-38) can be helpful.
5 Description of test chamber
The test chamber shall be so constructed that:
a) the temperature in the working space can be varied cyclically between 22 °C to 28 °C as
well as the appropriate high conditioning temperature in a period specified in 7.4 as well as
Figure 2 to Figure 5, as applicable;
b) the relative humidity in the working space can be maintained within the limits of Variant 1
or Variant 2, or both, as given in 7.4 as well as in Figure 2 to Figure 5, as applicable;
c) the conditions prevailing at any point in the working space are uniform and are as similar as
possible to those prevailing in the immediate vicinity of suitably located temperature- and
humidity-sensing devices; the air in the chamber will therefore be continuously stirred at a
rate necessary to maintain the specified conditions of temperature and humidity;
d) the specimen under test is not subjected to radiant heat from the chamber conditioning
processes;
e) the water used for the chamber humidity system complies with the limits given in
IEC 60068-2-67;
f) any water is continuously drained from the chamber and not used again unless it has been
re-purified;
g) the materials used in the construction do not cause any significant corrosion of the
specimen, or degradation of the quality of the humidifying water;
h) injected moisture, when applicable, is not directly applied to the specimen but injected
remotely from the specimen. Precautions shall be taken to ensure that no droplet of injected
water deposits on the specimens.
Precautions should be taken to ensure that no condensed water from the walls and roof of the
test chamber can fall on the specimen. The specimen should not significantly impede the air
flow.
6 Severities
The combination of the test variant, the conditioning temperature and the number of cycles
define the severity of this test.
The severity shall be chosen from the methods given in Table 1:
Table 1 – Severities of Test Db
Method Variant High conditioning temperature Number of cycles
I 38 °C to 42 °C 2, 6, 12, 21, 56
II 53 °C to 57 °C 1, 2, 6
III 38 °C to 42 °C 2, 6, 12, 21, 56
IV 53 °C to 57 °C 1, 2, 6
7 Testing procedure
7.1 General
The specimens shall be introduced into the chamber either in the unpacked, switched-off, ready-
for-use state, or as otherwise specified in the relevant specification.
This document does not apply to specimens that are energized during the complete test, except
in exceptional cases. Specimens can be energized during the constant phases of the tests.
Measurements on energized specimens are typically carried out during constant phases of the
test unless specified otherwise (see 7.5).
Where no specific mounting is specified, the thermal conduction of the mounting shall be low,
so that for all practical purposes the specimen is thermally isolated.
The dimensions, properties or electrical loading of the specimens under test shall not
appreciably influence conditions within the test chamber.
The temperature and relative humidity limits given in this document are intended to take into
account errors in the measurement, slow changes of temperature, and temperature variations
of the working space.
NOTE 1 For further information on the working space, see IEC 60068-3-6.
The temperature and relative humidity refer to the control sensor of the test chamber, if not
specified otherwise.
The limits stated in this document do not take measurement uncertainty into consideration.
NOTE 2 The limits are valid for an empty test space during stabilized temperature/humidity conditions of the test.
In some conditions, where the specimen has a negligible impact on the chamber control, the limits can still be valid
for the chamber with specimen(s). For further information on the operation of a test chamber with specimens, see
IEC 60068-3-7.
NOTE 3 To maintain the relative humidity within the required limits, it can be necessary to keep the temperature
difference between any two points in the working space at any moment within narrower limits.
The dimensions of the specimen shall be such that it is entirely within the working space of the
test chamber. The specimen shall not be placed directly on the floor of the test chamber. The
position of the specimen shall be specified in the relevant specification.
7.2 Initial measurements
Initial measurements should be performed under standard atmospheric conditions for
measurements and tests (see IEC 60068-1).
The specimens shall be visually inspected and electrically and mechanically checked as
required by the relevant specification.
7.3 Preconditioning
The temperature of the specimens shall be stabilized between 22 °C and 28 °C.
This shall be achieved by either placing the specimens in a separate test chamber before
introducing them into the test chamber or adjusting the temperature of the test chamber
accordingly to stay within the specified limits (22 °C to 28 °C) after the introduction of the
specimens and maintaining them at this level until the specimens attain temperature stability.
A representative point (or points) on the specimen can be used for this measurement.
During the stabilization of temperature by either method, the relative humidity shall be within
the limits specified for standard atmospheric conditions for measurement and test
(see IEC 60068-1), i.e. 25 % RH to 75 % RH (see Figure 1).
Following stabilization, with the specimens in the test chamber, the relative humidity shall be
increased to not less than 95 % RH at a test chamber temperature of 22 °C to 28 °C in a time
not exceeding 1 h.
After the stabilization of the relative humidity in the test chamber the first test cycle begins.
Figure 1 – Test Db – Preconditioning period
7.4 Test cycle
a) The temperature of the test chamber shall be continuously raised to the chosen conditioning
temperature with the specified limits given for area A in Figure 2 to Figure 5 and Annex B
within a period of 2,5 h to 3,5 h. During this period of temperature increase (area A), the
relative humidity shall not be less than 95 % RH.
After 3 h 15 min the relative humidity shall not be less than 90 % RH. Condensation can
occur on the specimen during this temperature-rise period.
NOTE 1 The condensation condition implies that the surface temperature of the specimen is below the dew
point of the air in the test chamber.
b) The temperature shall then be maintained within the specified limits given for area B in
Figure 2 to Figure 5 and Annex B for the high conditioning temperature until 12 h after the
start of the cycle.
During this period (area B), the relative humidity shall be between 90 % and 96 % RH.
During the first and last 15 min it shall be between 90 % RH and 100 % RH.
c) The temperature shall then be lowered in accordance with one of the two variants given
below.
1) Variant 1, C
The temperature shall be lowered to 22 °C to 28 °C within 3 h to 6 h (see area C in
Figure 2, Figure 3 and Annex B) The applicable limits of the temperature and relative
humidity are given in Clause B.3.
The relative humidity shall be not less than 95 % RH. During the first 15 min it shall be
not less than 90 % RH.
NOTE 2 See Annex A for descriptions of the type of specimen suitable for Variant 1.
2) Variant 2, C
The temperature shall be lowered to 22 °C to 28 °C within 3 h to 6 h (see area C in
Figure 4, Figure 5 and Annex B). The applicable limits of the temperature and relative
humidity are given in Clause B.4.
The relative humidity shall be not less than 80 % RH.
NOTE 3 See Annex A for descriptions of the type of specimen suitable for Variant 2.
d) The temperature shall then be maintained between 22 °C and 28 °C with a relative humidity
of not less than 95 % RH until the 24 h cycle is completed (see area D in Figure 2 to Figure 5
and Annex B).
An example of test programming for each test procedure is given in Annex C.
NOTE 4 The type and design of the test system can affect its performance and require different features in the
programming of the test procedures.
Figure 2 – Test Db – Test cycle – Variant 1, Method I
Figure 3 – Test Db – Test cycle – Variant 1, Method II
Figure 4 – Test Db – Test cycle – Variant 2, Method III
Figure 5 – Test Db – Test cycle – Variant 2, Method IV
7.5 Intermediate measurements
The relevant specification can require functional tests during the conditioning.
In order to carry out measurements on an energized specimen, the following parts of the
constant phases of the test cycles shown in Figure 2 to Figure 5 can be used:
– area B in Figure 2 to Figure 5 and Annex B;
– area D in Figure 2 to Figure 5 and Annex B.
During the test cycle, only temporary functional checks should be carried out, as permanent
operation of the specimen can interfere with the severity of the climatic stress applied to the
specimen.
If a different procedure is required, possible consequences for the climatic stress shall be
considered. The applicable procedure shall be determined in the relevant specification.
NOTE Some product specific standards can require different specifications.
Measurements preceded by a recovery, which would require removal of the specimens from the
test chamber, are not permissible during the conditioning. If it is desired to make intermediate
measurements, the relevant specification should define the measurements and the period(s)
during the conditioning after which they will be carried out.
8 Recovery
The relevant specification shall specify whether recovery shall be made at standard
atmospheric conditions for measurements and tests or at controlled recovery conditions
(see IEC 60068-1).
If controlled recovery conditions are required (see Figure 6), the specimen may be transferred
to another test chamber for this recovery period or may remain in the damp heat test chamber.
In the former case, the change over time shall be as short as possible and not more than 10 min.
In the latter case, the relative humidity shall be reduced to 73 % to 77 % RH in not more than
1 h.
The temperature shall then be adjusted to laboratory temperature within ± 1 K in not more than
1 h. The laboratory temperature shall be within the temperature of standard atmospheric
conditions for measurements and tests (see IEC 60068-1). For large specimens, the relevant
specification can allow longer change over times.
The recovery time of 1 h to 2 h is counted from the moment when the specified recovery
conditions have been obtained.
Specimens having a large thermal time constant may be submitted to recovery for a period
sufficient to attain temperature stability.
The relevant specification shall state whether any special precautions shall be taken regarding
the removal of surface moisture.
Figure 6 – Test Db – Recovery at controlled conditions
9 Final measurements
The specimens shall be visually inspected, and electrically and mechanically checked as
required by the relevant specification.
The measurements shall start immediately after the recovery period and the parameters most
sensitive to changes of relative humidity shall be measured first. The measurement of these
parameters shall be completed within 30 min, if not otherwise specified.
10 Information to be given in the relevant specification
When this test is included in the relevant specification, the following details shall be given as
far as they are applicable:
a) type of test (Variant 1 or 2; method I, II, III or IV);
b) preconditioning;
c) initial measurements;
d) details of mounting and supports;
e) number of cycles;
f) state of the specimen during conditioning;
g) measurements or loading during conditioning, or both;
h) recovery procedure;
i) special precautions to be taken regarding removal of surface moisture;
j) final measurements;
k) any deviation in procedure as agreed upon between customer and supplier.
11 Information to be given in the test report
As a minimum, the test report shall show the following information:
a) customer (name and address);
b) test laboratory (name and address and details of accreditation – if any);
c) test dates (dates when test was run);
d) type of test (Db);
e) test standard, edition (IEC 60068-2-30, edition used);
f) test specimen description (drawing, photo, quantity build status, etc.);
g) test chamber identity (unique identity of the chamber, e.g. internal laboratory identification
number or code);
h) test setup (details of mounting and supports, measuring points, etc.);
i) initial, intermediate and final measurements (if performed by the test laboratory);
j) required severities (from relevant specification);
k) test severities (preconditioning, temperatures, number of cycles, etc.);
l) performance of test specimens (results of functional tests, etc.);
m) observations during testing and actions taken (any pertinent observations);
n) test results (test summary, e.g. pass/fail decision).
In addition to the mandatory information the test report can include, for example:
o) purpose of test (development, qualification, etc.);
p) relevant laboratory test procedure (code and issue);
q) performance of test apparatus (set point temperature control, air flow, etc.);
r) air velocity or direction, or both (air velocity and direction of incident air to the specimen or
both);
s) uncertainties of chamber independent measuring system (uncertainties data);
t) calibration date (last and next due date);
u) measurements or loading during conditioning or both;
v) any deviation in procedure as agreed between customer and supplier (test setup, applicable
severities, etc.).
A test log should be written for the testing which can be attached to the report.

Annex A
(informative)
Selection of variant for the cooling period – Guidance
In this test two variants are included for the cooling period.
1) Variant 1, where the cooling rate shall be closely controlled during the first 90 min and the
relative humidity shall be not less than 95 % except for the first 15 min when it shall be not
less than 90 %. This variant requires specially designed test chambers.
Variant 1 is particularly suitable for specimens where moisture can penetrate due to the
breathing effect, for example, specimens which include hollow spaces where condensation
can occur on internal surfaces.
NOTE 1 For further information on the breathing effect, IEC 60068-2-38 can be helpful.
2) Variant 2 gives satisfactory reproducibility for all other types of specimens.
NOTE 2 Further information on the application of damp heat tests including a comparison of steady-state and cyclic
tests can be found in IEC 60068-3-4.

Annex B
(normative)
Supporting documentation for temperature
and humidity limits in the test sequences
B.1 General
In order to simplify evaluation of test routines for operating climatic test chambers, the
temperature and humidity limits of each test step for the programming of all test procedures are
given in Table B.1 to Table B.6.
B.2 Preconditioning
Table B.1 – Limits of relative humidity during preconditioning
Test step Time Lower limit Upper limit
h % %
1 0 45 75
a
t
2 45 75
s
a
t
3 45 100
s
b
4 < (t + 1 h) 95 100
s
a
t is the time required for the stabilization of the specimen temperature.
s
b
< (t + 1 h) is the time required to reach 95 % to 100 % relative humidity within the test chamber.
s
Table B.2 – Temperature limits during preconditioning
Test step Time Lower limit Upper limit
h °C °C
1 0 22 28
a
t
2 22 28
s
b
3 < (t + 1 h) 22 28
s
a
t is the time required for the stabilization of the specimen temperature.
s
b
< (t + 1 h) is the time required to reach 95 % to 100 % relative humidity within the test chamber.
s
B.3 Variant 1
Table B.3 – Limits of relative humidity and temperature during Variant 1
Relative humidity
Method I Method II
limits
Test Area (see
Test Lower Upper Lower Upper Lower Upper
step 7.4)
time limit limit limit limit limit limit
h % % °C °C °C °C
1 0 95 100 22 28 22 28
2 2,5 95 100 33,4 42 44,1 57
3 3,25 95 100 36,9 42 50,8 57 A
4 3,25 90 100 36,9 42 50,8 57
5 3,5 90 100 38 42 53 57
6 3,75 90 100 38 42 53 57
7 3,75 90 96 38 42 53 57
8 11,75 90 96 38 42 53 57 B
9 11,75 90 100 38 42 53 57
10 12 90 100 38 42 53 57
11 12,25 90 100 36,7 40,8 50,4 54,6
12 12,25 95 100 36,7 40,8 50,4 54,6
C
13 13,5 95 100 30 35 37,5 42,5
14 15 95 100 22 32,7 22 37,7
15 18 95 100 22 28 22 28
16 24 95 100 22 28 22 28 D
B.4 Variant 2
Table B.4 – Limits of relative humidity and temperature during Variant 2
Relative humidity
Method III Method IV
limits
Test Area (see
Test Lower Upper Lower Upper Lower Upper
step 7.4)
time limit limit limit limit limit limit
h % % °C °C °C °C
1 0 95 100 22 28 22 28
2 2,5 95 100 33,4 42 44,1 57
3 3,25 95 100 36,9 42 50,8 57 A
4 3,25 90 100 36,9 42 50,8 57
5 3,5 90 100 38 42 53 57
6 3,75 90 100 38 42 53 57
7 3,75 90 96 38 42 53 57
8 11,75 90 96 38 42 53 57 B
9 11,75 90 100 38 42 53 57
10 12 90 100 38 42 53 57
11 12 80 100 38 42 53 57
C
12 15 80 100 22 32,7 22 37,7
Relative humidity
Method III Method IV
limits
Test Area (see
Test Lower Upper Lower Upper Lower Upper
step 7.4)
time limit limit limit limit limit limit
h % % °C °C °C °C
13 18 80 100 22 28 22 28
14 18 95 100 22 28 22 28
D
15 24 95 100 22 28 22 28
B.5 Recovery
Table B.5 – Limits of relative humidity during recovery
Test step Time Lower limit Upper limit
h % %
1 0 73 100
a
2 t 73 100
sH
a
t
3 73 77
sH
b
t
4 73 77
sT
c
5 t 73 77
s
a
t is the time required for the stabilization of the relative humidity within the test chamber. It shall be less
sH
than 1 h, if not specified otherwise.
b
t is the time required for the stabilization of the temperature within the test chamber. It shall be less than
sT
1 h, if not specified otherwise.
c
t is the time required for the stabilization of the specimen temperature.
s
Table B.6 – Temperature limits during recovery
Test step Time Lower limit Upper limit
h °C °C
1 0 22 28
a
2 t 22 28
sH
a d
t (t – 1 K)
3 28
sH amb
b d
t (t – 1 K)
4 28
sT amb
b d d
5 t (t – 1 K) (t + 1 K)
sT amb amb
c d d
t (t – 1 K) (t + 1 K)
s amb amb
a
t is the time required for the stabilization of the relative humidity within the test chamber. It shall be less
sH
than 1 h, if not specified otherwise.
b
t is the time required for the stabilization of the temperature within the test chamber. It shall be less than
sT
1 h, if not specified otherwise.
c
t is the time required for the stabilization of the specimen temperature.
s
d
t is the ambient laboratory temperature.
amb
Annex C
(informative)
Supporting documentation for programming the set value
C.1 General
In order to simplify the creation of test routines for operating climatic test chambers, one
example of test programming for each test procedure is given in Table C.1 to Table C.4.
NOTE The type and design of the test system can affect its performance and require different features in the
programming of the test procedures.
The following examples represent only one possible programming of the test procedures.
Verifying the performance of the test chamber is recommended when the test routine is
programmed for the first time. The values listed in Table C.1 to Table C.4 refer to the set points
of the test chamber.
C.2 Preconditioning
Table C.1 – Example of programming of the preconditioning
Test step Time Temperature Relative humidity
h °C %
1 0 25 60
a
2 t 25
s
a
t
3 25
s
b
4 < (t + 1 h) 25 98
s
a
t is the time required for the stabilization of the specimen temperature.
s
b
< (t + 1 h) is the time required to reach 95 % to 100 % relative humidity within the test chamber.
s
C.3 Variant 1
Table C.2 – Example of programming of the relative humidity
and temperature (Variant 1)
Temperature
°C
Relative
Test step Test time Area (see 7.4)
humidity
Method I Method II
h  %
1 0 25 25 97
A
2 3,25 40 55 97
3 3,25 40 55 93
B
4 12 40 55 93
5 12 40 55 97
C
6 13,5 32,5 40 97
7 18 25 25 97
8 24 25 25 97 D
C.4 Variant 2
Table C.3 – Example of programming of the relative humidity
and temperature (Variant 2)
Temperature
°C
Relative
Test step Test time Area (see 7.4)
humidity
Method III Method IV
h  %
1 0 25 25 97
A
2 3,25 40 55 97
3 3,25 40 55 93
B
4 12 40 55 93
5 12 40 55 97
C
6 18 25 25 97
7 24 25 25 97 D
C.5 Recovery
Table C.4 – Example of programming of the recovery procedure
Test step Time Temperature Relative humidity
h °C %
1 0 25 75
a
t
2 25 75
sH
a
t
3 t 75
amb
sH
b
t t
4 75
sT amb
c
t
5 t 75
amb
s
a
t is the time required for the stabilization of the relative humidity. It shall be less than 1 h, if not specified
sH
otherwise.
b
t is the time required for the stabilization of the temperature within the test chamber. It shall be less than
sT
1 h, if not specified otherwise.
c
t is the time required for the stabilization of the specimen temperature.
s
d
t is the ambient laboratory temperature.
amb
Bibliography
IEC 60068-2-38, Environmental testing - Part 2-38: Tests - Test Z/AD: Composite
temperature/humidity cyclic test
IEC 60068-3-4, Environmental testing - Part 3-4: Supporting documentation and guidance -
Damp heat tests
IEC 60068-3-6, Environmental testing - Part 3-6: Supporting documentation and guidance -
Confirmation of the performance of temperature/humidity chambers
IEC 60068-3-7, Environmental testing - Part 3-7: Supporting documentation and guidance -
Measurements in temperature chambers for tests A (Cold) and B (Dry heat) (with load)

___________
SOMMAIRE
AVANT-PROPOS . 3
1 Domaine d'application . 5
2 Références normatives . 5
3 Termes et définitions . 5
4 Description générale . 5
5 Description de la chambre d'essai . 6
6 Sévérités . 6
7 Procédure d'essai . 6
7.1 Généralités . 6
7.2 Mesurages initiaux . 7
7.3 Préconditionnement . 7
7.4 Cycle d'essai .
...