The IP rating tells you how dust proof and waterproof the phone is. Useful for work phones for builders or people who want rugged phones. Also known as a International Protection rating. My business partner wants a tough phone as he does a lot of building work and I wondered how good the Lumia 920 was.
after seeing videos in youtube on the sturdiness of Lumia 920 , i can come to a conclusion that the phone case and the screen are very sturdy and there will be no problems in that.
i have read cases where there is dust inside the front camera lens.
other than that since the whole body is sealed , there is not going to much of dust affecting sensors.
Once I was on my bike, with lumia in hand and I crashed on to the ground and i was dragged for a few feets and my lumia hit the ground chin down and was dragged tooo.
nothing happened to it , except a slight scratch in the polycarbonate body.
but the IP rating of this phone I have no clue what it is