What are IP ratings and how much protection do they offer

Plenty of smartphone and other device manufacturers are now toting water and dust resistance as a key selling point for their devices. Device specifications now list IP67 or IP65 or similar ratings, corresponding to water and dust resistance, but have you ever wondered what these numbers are and what they signify? Not all ratings are created equal, and hence they should not give you the same amount of peace of mind. These ratings, which may appear to be just numbers, do carry significant meaning and it is essential to understand what each of them means before you decide to get adventurous with your smartphone. However, before we get into explaining what they mean, lets first understand why we need these ratings in the first place.

Why The Ratings
Okay, so the manufacturer says the phone is water resistant, but how “resistant” is it? Can you take it underwater for a swim or can it only withstand gentle rainfall? Will it survive an accidental spill? Similarly, just how much dust (and of what kind) infiltration can your device withstand without frying its circuits? There are so many different scenarios, so there was a need to standardize the level of abuse a device could withstand. Each rating tells you not only how much water or dust it can withstand, under what conditions. This standardization is what allows manufacturers equal footing when it comes to claiming water and dust resistance.

Understanding IPXX
When you see an IP67 rating, each character has a meaning of its own. IP stands for Ingress Protection, a code that must comply with the international IEC 60529 standard for a “device enclosure.” If a code begins with IP, its talking about water and dust resistance. The two numbers that follow “IP” also denote very different things.

The First ‘X’
The first number after the IP code denotes the device’s degree of protection against the entry of foreign solid objects. It ranges from 0-6, sometimes the 0 being replaced by an X. In this case, the device was not evaluated for dust resistance, and does not neccessarily signify a lack of dust resistence.. Interestingly, the 0-4 rating for particulate matter is a fairly simple test based on particle size, but for a rating of 5 or 6, the test is fairly complex. In order to have a rating of 5 or 6 for dust resistance, the device is hung in a dust-test chamber containing specially sized grains of talcum powder. Then, a vacuum line is introduced which will either create airflow (if the seals are leaky) or negative pressure (if they hold). The test runs of 8 hours or 80 volumes of air exchange and requires that the vacuum line does not exceed a rate of 60 volumes per hour. Depending on the results of the test, an IP5X rating is given if some talcum powder gets inside the device but does not impact its performance and an IP6X rating is given when no powder breaches the device surface.

The Second X
 Interestingly, the second X in the IP code actually caters to four distinct categories of tests; determining protection against dripping (IPX1, IPX2), spraying and splashing (IPX3, IPX4), jetting (IPX5, IPX6), and encompassing water (IPX7, IPX8). The criteria to pass these test is that in the event of a moisture breach, the safe and normal functioning of the device should not be impacted. Of these, let’s just consider the last ratings, IPX7 and IPX8, which deal with submersion of the device in water. In order to have an IPX7 rating, the device is submerged under water in such a way where the lowest point of the enclosure should be 100 cm below the surface of the water, and the highest point at least 15 cm below the surface. The device is then kept there for 30 minutes. Ideally, this is the highest level of standardized water resistance you can get on a phone, but an IPX8 rating ‘could’ be higher. In order to have an IPX8 rating, the test time and submersion depth are according to the manufacturer’s specifications and must be marked on the product. For example, a smartphone may have an IPX8 rating, but if it does carry one, it must specify the test conditions, along with having passed them as well.

But there is STILL a Catch
Interestingly, the IPXX rating system does not account for liquids, but only water. The system does not even account for seawater, which contains salt. What this means is that liquids such as milk, or hot liquids like tea or coffee could, in some consideration still cause liquid damage. Furthermore, if liquid (even water) isn’t completely removed from internal ports such as the charging port of the headphone jack, it will most definitely cause a short-circuit if you connect your charger or even a pair of headphones. Dust could have a similar impact if it is conductive in nature (such as fine rock dust). So here are the most common IP rating you will see on various devices, along with what they mean. 

Follow Us

Swapnil Mathur

Swapnil was Digit's resident camera nerd, (un)official product photographer and the Reviews Editor. Swapnil has moved-on to newer challenges. For any communication related to his stories, please mail us using the email id given here. View Full Profile