What Is Humidity?
This test is carried out to evaluate the equipment in high relative humidity conditions within the scope of Chapter 6 (“Humidity”) of the RTCA DO-160 “Environmental Conditions and Test Procedures for Airborne Equipment” standard. DO-160 is the exact same text as EUROCAE ED-14 and is recognized by ISO as ISO 7137.
Purpose of Humidity
The aim is to certify that aviation equipment meets the requirements for evaluation of equipment in high relative humidity conditions in flight and ground conditions and to complete equipment qualification.
Which Products Is Humidity Applied To?
- Avionics units and displays
- In-flight electronic equipment
- Communication and navigation devices
- Cabin and cargo compartment equipment
- Sensors and actuators
In Which Sectors Is Humidity Used?
Standards Related to Humidity
- RTCA DO-160Environmental conditions and test methods in aviation equipment test
- EUROCAE ED-14
- ISO 7137
- IEC 60945maritime navigational and radio communications equipment test
- Marine Equipment DirectiveEU ship equipment directive test
- IMO RequirementsInternational Maritime Organization requirements test
- SOLAS EquipmentEquipment covered by the safety of life at sea convention test
Humidity Conditions
- Kategoriler
- A (standard humidity), B (severe humidity), C
- Cycle
- Temperature and humidity cycles; number of days by category
- Relative humidity
- High humidity levels defined in the standard
- Function check
- At the end of the cycle and, if necessary, in the cycle
Equipment for Humidity
- Temperature-humidity chamber
- Insulation resistance measuring instrument
- Function monitoring
Sample Requirements for Humidity
- Category must be defined
- Initial insulation resistance should be measured
- Condensation management should be planned
Duration of Humidity
It depends on the category; The severe humidity category may exceed ten days.
Humidity Procedure
- 1The category and cycle program are determined.
- 2The specimen is placed in the chamber.
- 3Temperature-humidity cycles are applied.
- 4At the end of the cycle, function and insulation are measured.
- 5A visual inspection is performed.
Humidity Acceptance Criteria
The acceptance criteria are that the function continues, the insulation resistance meets the limit and there is no corrosion.
Evaluation of Results
Moisture ingress usually occurs at connector and housing junctions.
Humidity Report
- Applied standard, revision and Chapter 6
- Selected equipment category and justification
- Applied conditions and measurement results
- Function monitoring method and observations
- Environmental Qualification Form (DO-160 Environmental Qualification Form) entry
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Aviation equipment qualification requirements
- EASA/FAA certification principles
Denizcilik Testleri — What Does This Testing Field Cover?
The section below describes the field that the Humidity test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Marine testing shows that equipment used on board withstands the marine environment and shipboard operating conditions. The character of the environment is decisive: continuous salt-laden humidity, rolling and pitching, engine-borne vibration, limited opportunity for maintenance and the difficulty of evacuation in the event of a failure.
The most distinctive aspect of the field is the CONSEQUENCE OF FAILURE. A device that fails ashore is replaced; a navigation device that fails at sea means the ship does not know its position. Durability expectations and the certification burden for marine equipment are therefore markedly higher than for comparable equipment ashore.
Navigation and communication equipment is assessed under IEC 60945; this standard carries environmental durability, EMC and functional requirements together and distinguishes categories according to where the equipment will be mounted on board: protected, exposed deck and submerged categories are subject to different requirements.
On the digital interface side the IEC 61162 series is used. This is the body of protocols enabling devices on the bridge to talk to one another; in integrated bridge systems it must be shown that data exchange between devices works correctly.
On the shipboard electrical installation side the IEC 60092 series applies: cable types, installation rules, protection coordination and fire behaviour. Flame spread and halogen-free construction carry particular weight for cables on board, because smoke in an enclosed space directly obstructs evacuation.
On the shock side, naval vessels carry their own regime: the MIL-S-901 high-impact shock test simulates the effect of an underwater explosion. Testing at this scale is not required for civil ships, but vibration and inclination/roll tests are standard.
On the regulatory side the Marine Equipment Directive (MED) is decisive: equipment within scope carries the "wheelmark" and this is a regime SEPARATE from CE. Behind the requirements stand the SOLAS convention and International Maritime Organization resolutions; the scope list is updated regularly.
Classification societies add a second layer. DNV, Lloyd's Register, ABS, Bureau Veritas and similar bodies issue their own type approvals; a shipyard usually requires both the wheelmark and the relevant class approval. The two processes do not substitute for one another.
Method groups in this field
Environmental durability
Temperature, humidity, salt fog, vibration, rain and immersion under IEC 60945; levels according to the mounting category.
Electromagnetic compatibility
The EMC sections of IEC 60945; emission and immunity requirements specific to the shipboard environment.
Mechanical
Vibration, shock, inclination and roll tests; MIL-S-901 high-impact shock for naval vessels.
Electrical installation
Cable and installation requirements under the IEC 60092 series; cable fire behaviour and halogen-free construction.
Digital interface
Data interface conformity under the IEC 61162 series and integrated bridge system compatibility.
Fire safety
Reaction to fire, smoke and toxicity for shipboard interior materials; fire resistance for hoses and penetrations.
Commonly confused in this field
- The wheelmark is not the CE marking; it is a different regulatory regime with its own scope list.
- MED approval and classification society type approval do not substitute for one another; a shipyard usually requires both.
- The IEC 60945 category selection depends on the mounting location; an approval obtained for a protected area is not valid for an exposed deck.
- An approval obtained for a civil ship does not satisfy naval shock requirements.
- An onshore EMC report is not sufficient for marine use; IEC 60945 defines its own limits and set-ups.
- Scope lists are updated; equipment once outside the scope may later fall within it.
Which decisions these results support
- Marine equipment type approval and the wheelmark
- Classification society type approval
- Compliance with shipbuilding and shipyard procurement specifications
- Shock qualification in naval programmes
- Verification of integrated bridge system compatibility
Related Tests
Frequently Asked Questions About Humidity
How is the equipment category determined?
The category is selected based on the equipment's mounting location on the aircraft (pressurized/non-pressurized, heated/unheated area) and aircraft type. Category selection directly determines the test conditions and is declared in the qualification form.
Is there any difference between DO-160 and ED-14?
No. RTCA DO-160 and EUROCAE ED-14 are exactly the same text; the two are considered equivalent.