What is water and dust protection IP level

IP marking standard refers to the water and dust protection level which is determined by IEC(International Electronic Commission)
The code is divided into 3 parts, the first number (dust protection), the second number(water protection), and the third letter (protection against hazardous components).

1. First letter (dust)

Level	Object size protected against	Effective against
0	—	No protection against contact and ingress of objects
1	>50 mm	Any large surface of the body, such as the back of a hand, but no protection against deliberate contact with a body part
2	>12.5 mm	Fingers or similar objects
3	>2.5 mm	Tools, thick wires, etc.
4	>1 mm	Most wires, screws, etc.
5	Dust protected	Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment.
6	Dust tight	No ingress of dust; complete protection against contact (dust tight)

2. Second Letter (water)

Level	Protection	Test method
0	—	No protection
1	Dripping water	10 mins of 1 mm rainfall
2	Dripping water at 15° tiled	10 mins of 3 mm rainfall tiled 15°
3	Spraying water	5 mins of 0.7 litre per minute water
4	Splashing water	5 mins of 10 litre per minute water
5	Water jets	3 mins of water jet at 12.5 litre per minute
6	powerful water jets	3 mins at 100 litre per minute
7	1m immersion	30 mins at 1m below surface
8	immersion beyond 1m	test at 3m or deeper constantly
9k	high temperature/pressure water	16 litre per minute of 10,000Pa water at 80C

3. Other hazardous protection

Letter	Meaning
f	Oil resistant
H	High voltage device
M	Device moving during water test
S	Device standing still during water test
W	Weather conditions