What Is Immersion Testing? Methods, Standards, and Applications
What Is Immersion Testing?
Immersion testing is an accelerated evaluation method that submerges products, components, packaging, or material specimens in defined liquid media — typically water, salt solutions, corrosive fluids, or organic solvents — for defined periods to assess their resistance to liquid ingress, chemical attack, dimensional change, and performance degradation under sustained liquid exposure.
Immersion testing is used across the electronics, automotive, marine, coatings, and materials industries to simulate field conditions where products may be exposed to water, cleaning fluids, hydraulic fluids, or process chemicals during their service life.
Types of Immersion Testing
Water Immersion for Electronics — IEC 60529 IPX7 and IPX8
Electronic equipment IP (Ingress Protection) ratings include water immersion tests:
- IPX7: Immersion in 1 metre of water for 30 minutes — simulates temporary submersion (dropped in a puddle, stream crossing)
- IPX8: Continuous immersion at depth and duration specified by the manufacturer — for submersible electronics designed for extended underwater use
After immersion, the equipment is evaluated for any water ingress that could cause an electrical malfunction through visual inspection of internal surfaces and functional testing at all water-contact points.
Hydrostatic Pressure Immersion (IEC 60529 IPX8 Custom)
For higher-pressure underwater applications (diving equipment, underwater sensors, subsea connectors), immersion tests are conducted at elevated hydrostatic pressure — simulating service at 100 m, 300 m, or 1000 m water depth. Test pressure = ρgh (water density × gravitational acceleration × depth).
Chemical Resistance Immersion Testing (ASTM D543, ISO 175)
Polymer and elastomer specimens are immersed in specified chemical reagents (acids, alkalis, solvents, hydraulic fluids, fuels) at specified temperatures for specified periods. After immersion, dimensional change, mass change, hardness, tensile strength retention, and appearance are evaluated to characterise chemical resistance and select materials compatible with the chemical service environment.
Water Absorption Immersion (ASTM D570, ISO 62)
As covered in Blog 57 of Series 2, standardised immersion at 23°C for 24 hours or until equilibrium measures plastic and composite water absorption — governing dimensional stability and wet mechanical properties.
Coatings Chemical Immersion (ASTM D1308 / ISO 2812-2)
Coated test panels are partially or fully immersed in defined chemical reagents to evaluate coating chemical resistance — relevant to tank-lining coatings, valve and pump coatings, and industrial maintenance coatings in chemical processing plants.
Package Immersion Integrity Testing (ASTM F1929)
Dye immersion testing for medical device sterile packaging — as covered in Blog 71 of Series 2. The package is filled with a dye solution and inspected for seal-channel leakage.
Immersion vs. Spray and Condensation Testing
Immersion testing provides the most severe and sustained liquid contact — more aggressive than spray (IEC 60529 IPX4–IPX6) and condensation (IEC 60068-2-30) tests. The appropriate test method is selected based on the actual service exposure scenario:
- Occasional splash → IPX3/IPX4 spray
- Temporary submersion → IPX7 immersion
- Continuous submersion → IPX8 continuous immersion
- Chemical process contact → ASTM D543 chemical immersion
Industrial Applications
In the automotive industry, connectors and sensors in wet areas (underbody, wheel wells, engine bay washing zones) undergo IPX7/IPX8 immersion testing per LV 214 and OEM specifications. In marine electronics, navigation instruments and chart plotters are IP68 rated — requiring continuous immersion qualification. In the coatings industry, protective tank linings for water and chemical storage are immersion tested per ASTM C581 and NACE TM0174 to verify long-term chemical resistance.
Conclusion
Immersion testing is a critical evaluation method for assessing how materials and products perform under sustained exposure to liquids. Simulating real-world conditions, such as water submersion, chemical contact, and pressurized environments, reveals vulnerabilities related to leakage, corrosion, swelling, and material degradation. Implementing appropriate immersion tests ensures product reliability, safety, and compliance across demanding applications — making it an essential tool in material selection, product qualification, and long-term performance validation.
Why Choose Infinita Lab for Immersion Testing?
Infinita Lab provides IP immersion testing, chemical-resistance immersion testing, water absorption testing, and package-immersion integrity testing through our nationwide, accredited product and materials testing laboratory network.
Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you.
Frequently Asked Questions (FAQs)
What is the difference between IPX7 and IPX8 water immersion protection? IPX7 is tested by immersing the product to 1 metre depth for 30 minutes — representing temporary submersion. IPX8 is tested at greater depth and/or longer duration specified by the manufacturer — representing continuous submersion. IPX8 requires the manufacturer to specify the exact test conditions (depth and duration) in the product documentation.
How does immersion testing differ from the shower test (IPX5/IPX6)? IPX5/IPX6 spray/jet tests direct water at the product from a nozzle — simulating splashing and water jet contact. IPX7/IPX8 immersion tests submerge the entire product — simulating complete submersion with hydrostatic pressure forcing water into any ingress path. Immersion is significantly more severe than spray tests and reveals failure modes (hydrostatic pressure forcing water past seals) that spray tests miss.
Can immersion testing detect microscopic seal failures in electronics? IPX testing evaluates functional performance after immersion — water that enters but does not cause electrical failure within the test period would not be detected. More sensitive internal water ingress detection methods (fluorescent tracer solutions, internal humidity sensors, pressure decay testing) can detect seal failures below the functional failure threshold — relevant for long-term reliability prediction beyond the IPX test duration.
What materials require chemical immersion testing before use in process equipment? All elastomeric seals, polymer O-rings, and non-metallic components in contact with process chemicals require immersion compatibility testing per ASTM D543 or equivalent. This is especially critical for: EPDM, Buna-N (NBR), Viton (FKM), PTFE, PVDF, and polyurethane seals exposed to process solvents, acids, alkalis, or oxidising agents in chemical processing, semiconductor, and laboratory equipment.
What is the standard temperature for ASTM D543 chemical resistance immersion testing? ASTM D543 specifies immersion at 23°C ± 2°C as the standard condition. Elevated temperature immersion tests (50°C, 70°C) are used to accelerate chemical attack — better representing hot process fluid exposure and enabling lifetime prediction through Arrhenius modelling of chemical degradation rates.
