The classification system for the sealing effectiveness of the enclosure of electrical and electronic equipment againts the ingress into the equipment of foreign bodies e.g. dust, moisture, tools, fingers etc. uses the letters IP (ingress protection) followed by two or three digits. An X is used in place of a digit if there is only one classification e.g. IPX4 (which only addresses resistance to moisture). The IP rating is particularly important when choosing an outdoor camera or webcam.
The first digit of the IP code indicates the degree that persons are protected against contact with moving parts (other than smooth rotating shafts, etc.) and the degree that equipment is protected against solid foreign bodies intruding into an enclosure.
The second digit indicates the degree of protection of the equipment inside the enclosure against the harmful entry of various forms of moisture (e.g. dripping, spraying, submersion, etc.)
1st Digit Protection
0 No Special Protection
1 Protection from a large part of the body such as a hand (but no protection from deliberate access); from solid objects greater than 50mm in diameter.
2 Protection against fingers or other object not greater than 80mm in length and 12mm in diameter.
3 Protection from entry by tools, wires, etc., with a diameter of thickness greater than 1.0mm.
4 Protection from entry by solid objects with a diameter or thickness greater than 1.0mm
5 Protection from the amount of dust that would interfere with the operation of the equipment.
6 Dust tight.
2nd Digit Protection
0 No special protection.
1 Protection from dripping water.
2 Protection from vertically dripping water.
3 Protection from sprayed water.
4 Protection from splashed water.
5 Protection from water projected from a nozzle.
6 Protection against heavy seas, or powerful jets of water.
7 Protection against immersion.
8 Protection against complete, continuous submersion in water.
