Currently the main evaluation standard for the waterproofness of waterproof electrical connector is based on IP. The protective property of the waterproof electrical connector can be judged according to the last two numbers of IPXX—XX. The first X is from 0 to 6 (6 at most) and the second X is from 0 to 8 (8 at most). Thus, the highest protection grade is IP68.

The Level of Protection against Solid Matters (The First X)
0 :No protection;
1 :Protection against invasion of more than 50mm long solid matters, equivalent to the length of a hand;
2: Protection against invasion of 12.5mm long solid matters, equivalent to the length of a finger;
3: Protection against invasion of 2.5mm long solid matters, equivalent to the length of a wire or a tool;
4: Protection against invasion of more than 1.0mm long solid matters, equivalent to the length of a wire or a stripped wire;
5: Prevent the damage caused by dust;
6: Dust-proof;
Water-proof Level (The Second X)
0: Not water-proof;
1: Protection against water drops;
2: The shell is protected from damage caused by water drops when it inclines 15°;
3: The shell is protected from damage caused by water or rainwater dropped at an angle of 60°;
4: The shell is protected from damage caused by liquid poured in any direction;
5: It is protected from damage caused by washing with water.
6: It is protected from damage caused by injection water and can be applied to cabins;
7: It can be soaked in water for a short time;
8: It can be soaked in water under certain pressure.
The testing equipment, test conditions and test time of IP68 test are decided through discussion between both parties. The severe degree is quite higher than the lower level of protection. The IP68 test of the waterproof electrical connector for cruise ship: It can work for two weeks and prevent water invasion in 10m deep water. Moreover, it can still keep excellent property after 12h breaking test in 100m deep water.