How IP Ratings Are Tested: Inside the Laboratory
From dust chambers to immersion tanks, here is exactly how each IP digit is verified in accredited laboratories.
IP testing is performed in accredited laboratories according to IEC 60529. Each digit has a specific apparatus and procedure that must be followed precisely.
For solid protection, digits 1–4 use calibrated access probes (spheres, fingers, wires) to verify that hazardous parts cannot be contacted. Digit 5 and 6 use a dust chamber circulating fine talcum powder for up to 8 hours, sometimes with the enclosure under reduced internal pressure to simulate real-world suction.
For liquid protection, digits 1–2 use a drip box; digits 3–4 use an oscillating tube or spray nozzle; digits 5–6 use standardized nozzles at defined pressure (30 kPa and 100 kPa respectively).
Digit 7 immersion uses a tank with the enclosure's lowest point 1 m below the surface for 30 minutes. Digit 8 uses manufacturer-specified conditions, typically deeper and longer. Digit 9K uses a high-pressure fan nozzle at 80 °C and 8–10 MPa.
After each test, the enclosure is inspected for water or dust ingress. 'Harmful effects' is the pass/fail criterion—not absolute dryness. A trace amount of water may be acceptable if it does not impair safety or operation.