💦 Test Db: Damp heat, cyclic (12 h + 12 h cycle) — PN-EN 60068-2-30

Electronics and EMC PN-EN 60068-2-30

Overview

THE STANDARD CHANGED SIXTEEN DAYS BEFORE THIS ENTRY. PN-EN 60068-2-30:2008 in the Polish-language version, implementing IEC 60068-2-30:2005, has on its PKN card the header "Wycofana i zastąpiona przez PN-EN IEC 60068-2-30:2026-09 - wersja angielska" [Withdrawn and replaced by … — English-language version] and the withdrawal date 09-09-2026. The new edition (publication 09-09-2026, 34 pages, KT 65) implements EN IEC 60068-2-30:2025 and IEC 60068-2-30:2025. The Polish text of this test has therefore ceased to be current — the English text applies. In the accreditation scopes 12 notations still cite "PN-EN 60068-2-30:2008" (state on 25.09.2026).

WHAT THE 2025 EDITION CHANGED — ACCORDING TO ITS FOREWORD (extract made available by the publisher): the requirements for the chamber were changed; temperature tolerances were replaced by LIMITS; the figures were updated; the limits of temperature and relative humidity during conditioning were changed; the intermediate measurements and the requirements for the report were changed. The new scope on the PKN card adds two things that were not there: the method can be used to validate the PACKAGING of the specimen for transport and storage, and for specimens that are POWERED during the test the document is applied only in exceptional cases. The numbers described below come from the 2005 edition — we do not have the changed values of the 2025 edition.

SCOPE (clause 1 of the 2005 edition and the PKN card): the suitability of components, equipment and other products for use, transport and storage under conditions of high humidity combined with cyclic temperature changes, usually producing condensation on the surface of the specimen. For small specimens of low mass condensation may not occur — the standard then refers to the procedure of IEC 60068-2-38.

SEVERITY — TWO NUMBERS, CHOSEN FROM A LIST (clause 5 of the 2005 edition): the severity consists of the upper temperature and the number of cycles, chosen from a list: • upper temperature 40 °C — number of cycles 2, 6, 12, 21 or 56; • upper temperature 55 °C — number of cycles 1, 2 or 6. The notation "próba Db" [test Db] without these two numbers does not say what was tested.

THE 24-HOUR CYCLE (7.2–7.3 of the 2005 edition): • stabilisation of the specimens at 25 °C ± 3 K, then relative humidity of at least 95 %; • rise to the upper temperature in 3 h ± 30 min, humidity not less than 95 % (in the last 15 min not less than 90 %) — condensation on the specimen may occur during this time; • holding the upper temperature ±2 K until 12 h ± 30 min from the beginning of the cycle, humidity 93 % ± 3 %; • lowering to 25 °C ± 3 K within 3 h to 6 h, in one of TWO VARIANTS: in variant 1 the rate of fall in the first one and a half hours corresponds to reaching 25 °C in 3 h ± 15 min, and the humidity does not fall below 95 %; in variant 2 there is no requirement for the first one and a half hours, and the humidity is not less than 80 %; • holding 25 °C ± 3 K at a humidity of at least 95 % until the end of the 24 h. The variants differ only in the temperature-fall phase — Annex A gives the type of specimen appropriate for each (we did not have this annex). In the accreditation scopes two entries cite the standard "z wył. p. 7.3.3, wariant 1" [z wył. p. = excluding clause, wariant = variant] — these laboratories perform variant 2 only.

CHAMBER AND WATER (clause 4 of the 2005 edition): a temperature difference of more than 1 K between any two points of the working space makes it impossible to maintain the required humidity; short-term fluctuations should be kept within ±0.5 K; humidification water with a resistivity of not less than 500 Ωm; condensate is drained continuously and not reused without purification; condensed water must not drip onto the specimens. The tolerances of this standard do not take measurement uncertainty into account (clause 3).

RECOVERY AND FINAL MEASUREMENTS (clauses 9–10 of the 2005 edition): with recovery under controlled conditions in the same chamber, the humidity is lowered to 75 % ± 2 % within not more than 1 h; recovery lasts from 1 h to 2 h. The final measurements begin immediately after recovery, the parameters most sensitive to humidity first; unless otherwise agreed, their measurement is completed within 30 min. Measurements preceded by recovery that require the specimens to be removed from the chamber are not permitted during conditioning (clause 8).

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 23 entries at 19 laboratories. Forms of notation: "PN-EN 60068-2-30:2008" (12 — the edition withdrawn on 09-09-2026), "IEC 60068-2-30:2005" (3), "PN-EN 60068-2-30" without a year (2) and single "IEC 60068-2-30: 1980-01" (the 1980 edition — two editions before the one in force), "IEC 60068-2-30: 2005-08" and "EN 60068-2-30:2005". Objects: automotive electronics, electrotechnical products, components of fire alarm systems (short-circuit isolators, manual call points), gas volume conversion devices, rolling-stock equipment. Declared ranges: temperature "(23 - 85) °C", humidity "(50 - 95) % RH", "od 10 % rH do 98 % rH ±3 % rH" [od … do = from … to]. Next to the standard stand, among others, UN ECE Regulations Nos 97, 116, 162 and 163 and ISO 16750-4.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN 60068-2-30" — 16 laboratories and 20 entries, without any foreign entries. A key with the designation in force, "PN-EN IEC 60068-2-30", would show no laboratory today — no scope has it yet. The tab will not show 3 laboratories (AB 1776, AB 1899, AB 1974), which cite the IEC document alone.

WHAT WE DO NOT GIVE. The text of the edition IEC 60068-2-30:2005 made available by the publisher covers clauses 1–11 (without Annex A). Of the 2025 edition we have only the foreword with the list of changes — WE DO NOT GIVE the new limits of temperature and humidity. All the numbers in this entry concern the 2005 edition, i.e. PN-EN 60068-2-30:2008.

Method principle

The specimens are stabilised at 25 °C, the relative humidity is raised to at least 95 %, and they are then subjected to 24-hour cycles: a rise in temperature to the upper temperature (40 °C or 55 °C) in about 3 h, holding it until the 12th hour at a humidity of about 93 %, a fall to 25 °C in 3–6 h at high humidity and holding 25 °C until the end of the day. During the rise in temperature the surface of the specimen is colder than the dew point of the air and water vapour condenses on it. After the specified number of cycles, recovery and final measurements follow.

Applications

• Electronics and electrical engineering intended for operation, transport and storage in a humid climate with temperature changes
• Components of fire alarm systems — a test cited by product standards (short-circuit isolators, manual call points)
• Automotive electronics — next to ISO 16750-4 and UN ECE Regulations
• Gas volume conversion devices and transmitters — the effect of damp heat on metrological properties
• From the 2025 edition: validation of the packaging of the specimen for transport and storage (PKN card)

Key parameters

Standard

Standard number

PN-EN IEC 60068-2-30:2026-09 (wersja angielska; wprowadza EN IEC 60068-2-30:2025 [IDT], IEC 60068-2-30:2025 [IDT]); zastąpiła PN-EN 60068-2-30:2008 (wersja polska; wprowadzała EN 60068-2-30:2005 i IEC 60068-2-30:2005)

Title (PL)

Badania środowiskowe — Część 2-30: Próby — Próba Db: Wilgotne gorąco, cykliczne (cykl 12 h + 12 h)

Title (EN)

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

Step-by-step procedure

1. Severity and variant

   From the product specification: the upper temperature (40 °C or 55 °C), the number of cycles from the list and the variant of the temperature fall (1 or 2).

2. Initial measurements and placing the specimens

   Visual inspection and functional check; specimens unpacked, switched off, ready for use, unless the specification provides otherwise; mounting with low thermal conductivity.

3. Stabilisation

   Specimens at 25 °C ± 3 K until temperature stability, then humidity ≥ 95 % at 25 °C ± 3 K.

4. 24-hour cycles

   Rise to the upper temperature in 3 h ± 30 min; holding ±2 K until 12 h ± 30 min at 93 % ± 3 %; fall to 25 °C in 3–6 h according to the variant; holding 25 °C at ≥ 95 % until the end of the day.

5. Recovery

   Under standard or controlled conditions; in the same chamber: humidity to 75 % ± 2 % in ≤ 1 h, then laboratory temperature in ≤ 1 h; recovery 1–2 h.

6. Final measurements

   Immediately after recovery, the parameters most sensitive to humidity first — within 30 min, unless otherwise agreed.

7. Report

   State the edition of the standard (2008/2005 or 2026/2025), the upper temperature, the number of cycles and the variant — the first two numbers form the severity, the variant changes the course of the cycle.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Hot and humid air when opening the chamber — risk of steam scalding
• Condensation on powered products — risk of short circuit; the 2025 edition permits testing of powered specimens only in exceptional cases
• Water in the humidification system — check its cleanliness so that microorganisms do not develop

Frequently asked questions