According to DIN40050-9: 1993 protection class IP69K standard test methods. The first characteristic value (6) Test conditions: Test of dust air mixtures vacuum test vacuum: ≤ 2kpa (20mbar) Test Time: 8h experimental dust: 50% of the lime powder and 50% of the soot particle size distribution: 33% by weight ≤ 32μm 67%> 32μm, but ≤ 250μm the second eigenvalue (9K) Test conditions: Test the water intrusion test system tests the protective devices: high-pressure water gun / air duct nozzle spray angle :0-30 ° -60 ° -90 ° Spray distance: 100 ~ 150mm-spin on the table - speed of 5 ± 1 r / min water flow rate :14-16 l / min ± 5% Pressure: 8000 ~ 10000kpa (80 ~ 100bar) water temperature: 80 ° ± 5 ℃ Test Time: 30 seconds in each direction, the first characteristic value (6) of the definition: there is no dust infiltration. The second eigenvalue (9K) definition: in any direction to the chassis, using water high pressure water injection pressure, without causing harm.