Sand & Dust Testing at TechnoLab

Sand and Dust Testing of Encapsulated Control Electronics
According to RTCA/DO-160G Section 12

1. Background

Modern passenger aircraft rely on numerous electronic control units (ECUs) to ensure safe and reliable operation of critical and non-critical systems. These electronic modules are often installed in locations where exposure to environmental contaminants such as sand and dust cannot be completely excluded.
Typical exposure scenarios include:

• Ground operation at airports located in arid or desert regions
• Taxiing or takeoff on runways contaminated with fine particulate matter
• Maintenance environments where airborne dust may be present

To ensure operational reliability, avionics equipment must demonstrate resistance to particle ingress and contamination. Environmental qualification is therefore performed according to RTCA/DO-160G, which defines standardized environmental test procedures for airborne equipment.
This case study describes the sand and dust qualification testing of an encapsulated electronic control unit (ECU) housed in a sealed aluminum enclosure intended for installation in a passenger aircraft.

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2. Device Under Test (DUT)

The Device Under Test (DUT) was a flight control interface module designed to regulate auxiliary aircraft systems.
Key characteristics of the DUT:
The test objective was to verify that sand and dust exposure does not impair functionality, cause electrical failure, or penetrate the enclosure.

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3. Test Standard

Testing was performed in accordance with:

• RTCA/DO-160G – Environmental Conditions and Test Procedures for Airborne Equipment
• Section 12 – Sand and Dust

Section 12 specifies environmental simulation to evaluate equipment performance when exposed to airborne particulate matter.
The test procedure consists of two separate evaluations:

• Dust Test – fine particles capable of penetrating small gaps
• Sand Test – larger particles that may cause abrasion or mechanical interference

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4. Test Objectives

The primary objectives of the test were:

• Verification of enclosure integrity against dust ingress
• Assessment of mechanical resistance against sand particle impact
• Confirmation of electrical functionality during and after exposure
• Detection of contamination on connectors, cooling surfaces, or seals

The DUT remained powered and operational during exposure to evaluate real operating conditions.

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5. Test Equipment

Testing was conducted using a controlled environmental sand and dust chamber capable of generating defined particle concentrations and airflow conditions.
Typical chamber capabilities included:

• Controlled airflow velocity
• Recirculation of calibrated particulate material
• Particle size control
• Temperature stabilization
• Monitoring of particle concentration

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6. Test Conditions

The following environmental parameters were applied according to the relevant DO-160G Category:
The chamber continuously circulated particulate material while maintaining controlled airflow across the DUT surfaces.

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7. Test Procedure

The test was conducted in the following sequence:

1. Pre-test inspection
   • Visual inspection of enclosure seals and connectors
   • Functional verification of the control electronics
   • Documentation of baseline electrical parameters
2. Dust exposure
   • Fine dust introduced into the chamber
   • Airflow directed toward DUT surfaces
   • DUT operated continuously during exposure
3. Sand exposure
   • Larger sand particles circulated within the chamber
   • Increased airflow velocity applied
   • Mechanical impact and abrasion simulated
4. Post-exposure evaluation
   • Visual inspection
   • Functional performance verification
   • Internal inspection of enclosure

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8. Post-Test Inspection

After completion of the test cycle, the DUT was removed from the chamber for detailed evaluation.
Inspection included:

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9. Test Results

The following observations were recorded: No particles were detected inside the aluminum enclosure after opening the DUT.
The device continued to operate normally during the test and passed all post-test functional verification procedures.

10. Conclusion

The encapsulated avionics control unit successfully passed the sand and dust environmental qualification according to RTCA/DO-160G Section 12.
Key findings:

• The aluminum enclosure provided effective protection against particulate ingress.
• Connector interfaces and sealing concept remained intact.
• No functional degradation occurred during or after exposure.

The tested device therefore meets the environmental robustness requirements for operation in airborne environments where sand and dust exposure may occur.

11. Value of Sand and Dust Testing for Aviation Systems

Environmental qualification according to DO-160 ensures that airborne equipment remains reliable even in harsh operational environments.
For aircraft operators and manufacturers, such testing:

• Prevents premature electronic failures
• Validates enclosure protection concepts
• Supports certification of airborne equipment
• Improves long-term reliability and maintainability

Dust and Sand Environmental Testing according to DIN EN IEC 60068-2-68
Example: Plastic Functional Component for Use in a Passenger Vehicle

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1. Background

Passenger vehicles operate worldwide in environments where dust and sand particles are frequently present. Examples include:

• gravel roads and construction zones
• agricultural regions
• desert and semi-arid climates
• winter roads treated with sand

Components installed in exposed vehicle areas—such as the wheel arch, underbody, or engine compartment—must maintain functionality despite continuous contamination by airborne particles.
Dust contamination can lead to:

• blockage of ventilation openings
• malfunction of sensors
• abrasion of surfaces
• infiltration into connectors and seals

To validate environmental durability, a plastic wheel-speed sensor housing used in the wheel arch area of a passenger vehicle was tested according to:
DIN EN IEC 60068-2-68 – Environmental testing – Test L: Dust and sand.
This standard defines several sub-test methods that simulate different mechanisms by which dust and sand interact with equipment.

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2. Structure of the Standard: Test Methods La, Lb and Lc

DIN EN IEC 60068-2-68 differentiates between three types of environmental exposure.
These three mechanisms simulate different real-world contamination processes affecting automotive components.

3. Device Under Test (DUT)

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4. Test Method La – Non-abrasive Fine Dust

Test principle
Test La evaluates the effect of airborne fine dust particles suspended in air. The particles are circulated inside a chamber to simulate environments where dust remains airborne for extended periods.
Typical real-world scenarios include:

• vehicles driving on dry unpaved roads
• dust clouds generated by traffic
• agricultural environments

Typical test parameters:
Purpose:

• evaluate dust ingress into housings
• verify connector sealing effectiveness
• assess functional reliability under airborne dust exposure

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5. Test Method Lb – Freely Sedimenting Dust

Test principle
In test Lb, dust particles settle slowly onto the DUT by gravitational sedimentation without strong airflow.
This represents conditions where components are exposed to long-term dust accumulation, such as:

• vehicles parked in dusty environments
• engine compartments with gradual contamination
• equipment installed in partially protected areas

Typical test parameters:
Purpose:

• evaluate dust accumulation on surfaces
• assess potential blockage of openings
• examine effects of long-term contamination

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6. Test Method Lc – Blowing Dust and Sand

Test principle
Test Lc simulates dust and sand particles transported by airflow, impacting the DUT with defined velocity.
Compared to fine dust tests, this method introduces coarser particles capable of causing mechanical abrasion.
Typical real-world scenarios include:

• desert driving conditions
• off-road operation
• wind-driven sand exposure

Typical test parameters:
Purpose:

• evaluate surface abrasion resistance
• assess sealing under airflow-driven contamination
• test mechanical durability of polymer materials

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7. Test Results

Additional findings:

• sealing system remained intact
• connector contacts remained clean
• sensor signal output remained stable throughout testing

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8. Engineering Interpretation

The test results demonstrate that the sensor housing design provides sufficient protection against environmental dust contamination.
Key design factors contributing to the positive outcome include:

• optimized connector sealing geometry
• reinforced polymer housing material
• minimized tolerance gaps in the housing assembly

The glass-fiber reinforced polyamide material also provides good resistance to particle-induced abrasion.

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9. Conclusion

The plastic functional component successfully passed environmental testing according to DIN EN IEC 60068-2-68.
The component demonstrated reliable resistance to:

• airborne fine dust (La)
• long-term sedimenting dust (Lb)
• wind-driven dust and sand (Lc)

These results confirm that the component is suitable for installation in passenger vehicles exposed to dusty or sandy operating environments.

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Practical Relevance for Automotive Development

Environmental testing according to IEC 60068-2-68 enables automotive manufacturers to:

• validate dust protection concepts
• improve sealing system design
• verify long-term functional reliability of exposed components

For globally distributed vehicles operating under a wide range of environmental conditions, such testing is an essential step in ensuring durability and safety throughout the vehicle life cycle.

Sand and Dust Resistance of an Armored Vehicle Vision Window
Environmental Qualification according to MIL-STD-810H

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Background

Modern armored vehicles operate in some of the harshest environments on earth. Desert deployments, convoy operations in dry terrain, and rotor wash from nearby helicopters can expose vehicle surfaces to extremely high concentrations of airborne sand and dust.
One particularly critical component is the armored vision window (bullet-resistant transparent armor) used in the driver's or commander's viewing area of an armored vehicle. These windows typically consist of multi-layer laminated glass and polycarbonate structures, sometimes including:

• Hardened ballistic glass
• Polycarbonate energy-absorbing layers
• Anti-spall backing
• Optical coatings for glare reduction

During missions in desert environments such as the Middle East or North Africa, the window must maintain:

• optical transparency
• ballistic integrity
• seal integrity
• abrasion resistance

Exposure to high-velocity sand particles may degrade coatings, reduce visibility, or damage sealing systems. Therefore, the component must be tested for environmental durability according to MIL-STD-810H Method 510.7 (Sand and Dust).

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Test Objective

The purpose of the test was to verify that an armored vehicle vision window assembly can withstand prolonged exposure to airborne sand and dust without unacceptable degradation of its functional performance.
The test evaluated:

• Optical transmission
• Surface abrasion resistance
• Seal integrity of the window frame
• Particle ingress
• Mechanical stability of the laminated structure

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Test Specimen

Device Under Test (DUT):
Armored vehicle ballistic vision window assembly.
Construction:
The specimen was mounted in a representative vehicle frame section to simulate realistic installation conditions.

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Test Setup

The sand and dust test was conducted in a controlled environmental chamber capable of generating high concentrations of airborne particulate matter.
Test Standard: MIL-STD-810H Method 510.7 Sand and Dust
Two test procedures were performed:

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Test Conditions

Blowing Dust (Procedure I)

The window assembly was exposed to airborne dust while mounted vertically to simulate vehicle operation.

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Blowing Sand (Procedure II)

The sand stream was directed towards the external glass surface at a shallow angle, replicating high-speed desert driving conditions.

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Post-Test Inspection

After completion of the test, the window assembly was inspected for damage or functional degradation.
Inspection methods included:

• Optical microscopy
• Transmission measurement
• Seal leakage inspection
• Structural examination of lamination layers

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Test Results

The window remained fully operational and continued to meet the specified performance requirements.

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Engineering Assessment

The test results demonstrate that the laminated transparent armor system provides sufficient resistance to desert sand erosion and airborne dust contamination.
The following design elements contributed to the successful outcome:

• Hardened outer ballistic glass with high surface hardness
• Anti-abrasion coating
• Elastomeric sealing system preventing dust ingress
• Laminated construction preventing internal damage

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Conclusion

The armored vision window successfully passed environmental testing in accordance with MIL-STD-810H Method 510.7 (Sand and Dust).
Even under severe desert conditions with high-velocity sand exposure, the system maintained:

• optical functionality
• mechanical integrity
• environmental sealing

These results confirm that the component is suitable for deployment in desert operational environments.

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Marketing Summary

Proven durability in extreme desert environments.
Our environmental testing according to MIL-STD-810H Sand and Dust demonstrates that armored vehicle vision systems maintain optical clarity and structural integrity even under intense sand abrasion and airborne dust exposure.
TechnoLab’s environmental test capabilities enable manufacturers of defense systems, armored vehicles, and optical components to verify product reliability before field deployment.