In today's new devices, we often see that it is rated as IP53 or IP68, sometimes carrying two IP ratings. So what do those ratings mean and how would it affect how you use your devices?
First off, let's define what IP means. IP stands for Ingress Protection or International Protection depending on what the manufacturer prefers to call it. The IP code was introduced by the International Electrotechnical Commission, a non-profit organization that creates international standards for all sorts of electronically related devices, like appliances and yes, smartphones.
The IP rating is there to give you a clue on how element proof a device is. This would give you a better understanding of your device if it is just splash proof or outright submersible for a certain depth at a maximum time determined by the manufacturer.
So What does IP number means?
Now that we know who is behind the IP ratings, let's tackle the rating itself. It has two numbers, the first number is the protection level against solid particles, the higher the rating, the smaller particle it protects against. As a rule, an IP2X rating can protect against particles the size of a thumb. An IP6X rating has protection against dust level particles.
On the otherhand, the last number indicates the liquid protection of the device, specifically fresh water (take note of the word "fresh"). The highest rating a device can get is 9, but you may never see a phone that has this rating. Currently, the 8 rating is the most you can get, this means it is submersible beyond 1 meter in a time duration and maximum depth specified by the manufacturer. Ratings beyond the 6 mark are cumulative, meaning a device that has an IPX8 mark didn't go through the test for IPX7 mark.
What about the ratings that have X in them? It just means that it did not went through a test just yet, so you may see a IPX8, meaning it did not go through a particle test, or a IP6X rating for a device that did not go through a liquid protection test.
Important thoughts
Now that we know the meaning of the IP ratings in our devices, it is very important to remember that this ratings are done in a controlled environment. Manufacturers have also specific instructions for their own devices that have this ratings, most notably that although IP68 devices are submersible, it is to be done only in fresh water and not in salt water as it may cause corrosions on the components of the device.
Why does the ratings beyond IPX6 are not cumulative? It is because the ratings for IPX7 is specifically designed for water jet protection and IPX8 is for it's submersability. This two things are very diferrent that you should not try placing an IPX8 rated device under a strong downpour of water for quite a long time.
With this things in mind, we can now use our devices effectively.