IPX7 ratings set an expectation on how water and dust-proof a product is. IPX7 is commonly used for sealed electronics, where penetration by dust or moisture can lead to corrosion, electrical shorts and shock, internal condensation, performance issues, and failure. If promising an IP rating, manufacturers need to test their parts to ensure they meet the standards.
IP67 is an attribute test for no visible water ingress. You may correlate this into a measurable leak test.
1mtr of water equals 100 mbar of water pressure which is equal to 100 mbar of air pressure. No visible water can be converted to a non-water leak rate when using air pressure decay technology.
1mtr of water equals 100 mbar of water pressure
10mtr (33ft) 1000 mbar of water pressure
20mtr (66ft) 2000 mbar of water pressure
Water pressure can be directly correlated to air test pressure
Affected by leak path length and test pressure
Volumetric air flow over time (scc/min=Standard cubic centimetres per minute) allows a measurable and sensitive method of test allows a measurable and sensitive method of test.
Water will clog a certain size hole that air will flow through
Non-water leak rate ranges from 0.5 – 10scc/m of air flow dependent upon the leak path length
Flow is dependent upon the part design characteristics and leak path length
Short leak paths are more likely to leak water compared to longer leak paths with the same hole size. Shorter, thin wall paths required a lower reject limit (estimated) the range of 0.5 – 5scc/min)
Test part pressurized and submerged in fluid, pressurized gas forced out appears as bubbles.
Alternative to submersion is to use surfactant/soap solution on surface of part.
| Bubbles/min | Leak Rate |
|---|---|
| 2x 3.0 mm bubbles | 0.03 sccm |
| 10x 3.0 mm bubbles | 0.14 sccm |
| 30x 3.0 mm bubbles | 0.42 sccm |
| 75x 3.0 mm bubbles | 0.42 sccm |
| 2x 2.0 mm bubbles | 0.01 sccm |
IP Rating Attributes may affect each part differently:
Enclosures with sight windows or used in certain environments may require water vapor leak rates. Bubble Leak Leak rate ranges 0.5 – 3 scc/min
Enclosures that are: thick walled, large, altitude changes are subject to how pressure spray or drips maybe able to accommodate a higher leak rate Leak rate ranges 3- 10 scc/min
Pressure Decay - Open parts that will be sealed and pressured internally 1-10 scc/m
DP Pressure Decay - Parts that required low leak rates 0.5 -5 scc/m
Factors affecting Total Cycle Time:
Test Time= (volume x pa)/(Leak Rate x 14.69)x 60
Total time required for testing:
More time is required for large volume parts.
More time is required when the leak rate is decreased.
More time is needed for flexible parts due to larger and non-repeatable pressure loss
NOTE: This information corresponds to the current state of knowledge. SPLTA reserves the right to make technical changes. Liability for consequential damage resulting from the use of SPLTA products is excluded.
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