How is IP68 on a dustproof waterproof case accepted?

Answer: Confirm depth and time first: 1.5 m for 30 minutes and 3 m for 60 minutes both comply, so the contract states which.

Can IP66 and IP67 substitute for each other?

Answer: No. One resists a strong jet, the other short immersion, on different rigs.

Why draw a vacuum during the dust test?

Answer: Vacuum pulls dust into gaps; without it the test proves only external settling.

How often is the gasket replaced?

Answer: Three years outdoors, five indoors, or whenever compression set passes 20 percent.

Can air decay replace immersion?

Answer: No. It suits every unit, but immersion remains the only basis for the rating.

Dustproof Waterproof Case Standards: Tests and Limits

Quick answer: A dustproof waterproof case is accepted on two condition sets: particle size, concentration and vacuum, then depth, time and sequence. The IP number is only the conclusion.

Reading the IP Pair on a Dustproof Waterproof Case
Dust Testing: Particle Size and Vacuum
Immersion Testing: Depth and Time
Gasket Acceptance and Failure Criteria
Added Tests for Long Outdoor Duty
FAQ

1. Reading the IP Pair on a Dustproof Waterproof Case

The two digits are not a sum: the first covers solids, the second liquids. IP66 and IP67 are different rigs, a powerful jet against short immersion, and passing one proves nothing.

A dustproof waterproof case marked IP66 plus IP68 needs two water tests. IP68 alone, without depth and time, has no condition: 1.5 m for 30 minutes and 3 m for 60 minutes both qualify.

Rating	Dust	Water	Key condition
IP65	Dust tight	Jet	6.3 L/min, 30 kPa
IP66	Dust tight	Strong jet	12.5 L/min, 100 kPa
IP67	Dust tight	Short immersion	1 m, 30 min
IP68	Dust tight	Continuous immersion	Agreed

Treat the rating as a type test result, not a life statement; hinge wear and gasket ageing are held by rechecks.

2. Dust Testing: Particle Size and Vacuum

The standard test uses talcum at a median 75 µm and 2 kg per cubic metre for 8 hours, with the interior pulled to a 2 kPa vacuum and air drawn at 40 times the case volume per hour. The vacuum makes dust travel into gaps.

Dustproof Waterproof Case: olive green closed case angled on a green backdrop, three lid ribs, two matched latches, recessed folding handle, metal corner pieces

Without vacuum the test only proves external settling; many dustproof waterproof case models pass a static chamber and take dust within three months on a roof rack.

Compare particle size against gap width: 75 µm talcum passes a 0.1 mm gap, parting lines sit near 0.15 mm, and flat faces stop nothing. Tightness comes from gasket compression.

IP6X demands no visible deposit inside; IP5X tolerates some dust, so name the level.

3. Immersion Testing: Depth and Time

IPX5 is a nozzle at 6.3 L/min and 30 kPa for 3 minutes per face, IPX6 is 12.5 L/min at 100 kPa, IPX7 is 1 m for 30 minutes, and IPX8 is whatever depth and time the parties agree, commonly 3 m for 60 minutes.

Test	Condition	Misreading
IPX5	6.3 L/min, 30 kPa, 3 min per face	Read as rain
IPX6	12.5 L/min, 100 kPa, 3 min per face	Read as immersion
IPX7	1 m, 30 min	Read as soaking
IPX8	Agreed, often 3 m, 60 min	Left blank

Sequence matters: jet first, immersion second. The jet opens gaps the soak then exposes; reversed, a compressed gasket flatters the sample.

Temperature adds a variable. A dustproof waterproof case runs five cycles from minus 30 to plus 70 degrees, then enters water; a warm case in cold water pulls water inward, catching what a static soak misses.

4. Gasket Acceptance and Failure Criteria

The gasket is the only barrier. Acceptance fixes three numbers: hardness 70 Shore A, assembled compression 25 percent, and compression set no higher than 20 percent after 22 hours at 70 degrees.

Dustproof Waterproof Case: olive green closed case facing the camera on pale grey floor, two black latches, side folding handle, vertical ribs on the panel

After opening, check for droplets, discoloured absorbent paper, flattened or cut gasket.

The latch decides whether compression survives: after 5000 cycles the stroke may lose 20 percent at most, with an even lid gap.

Air decay suits a full check: charge to 30 kPa, hold 120 seconds, pass at 0.3 kPa loss. It cannot replace immersion but runs on every case.

5. Added Tests for Long Outdoor Duty

Outdoors, ultraviolet, thermal cycling, salt spray and dust deposit act together, so acceptance adds items beyond the standard test.

Added item	Condition	Verdict
UV ageing	1000 h, 0.76 W/m², 340 nm	No chalking or cracking
Cold bend	4 h at minus 30, then bend	No crack
Salt spray	96 h neutral	No red rust on metal
Latch life	5000 cycles	Stroke loss within 20 percent

The gasket ages first: silicone holds temperature, nitrile resists oil, EPDM balances both. A three-year cycle costs less than repairs.

The relief valve is easily missed: its disc must hold pressure without weeping, so test it alone at 30 kPa.

Conclusion

A dustproof waterproof case is accepted on two condition sets: particle size, concentration and vacuum, then depth, time and sequence. The rating is only a conclusion; conditions are reproducible. Buyers who pay for conditions receive a dustproof waterproof case.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.