Many gadgets come with claims of how they are waterproof and resistant to damage from dust and other contaminants. But those claims are sometimes quite nebulous. After all, what does waterproof really mean? Does it mean a device can survive a splash? Or that it can be dunked in a bath?
That's why the IP rating system was created. It provides a quantifiable measurement of how resistant a device is to environmental conditions. Let's look at how the ratings work.
The IP rating system is a measure of how well a device can repel materials that might damage it. IP stands for "Ingress Protection".
The first digit is about protection against solid objects and particulates. It's a scale from 0 to 6 with resistance to the smallest particles represented by the higher number. A zero means no protection. The "5" rating means "Ingress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment".
Each level refers to particles of a specific size.
- 0: No protection from any particles or objects
- 1: >50mm - such as a hand but not accidental bumping by a body part
- 2: >12.5mm - fingers or similar
- 3: <2.5mm - wires, tools, etc
- 4: >1mm - slender screws, nails and similar objects
- 5: dust protected - small amounts of dust may get in but not enough to hamper performance
- 6: dust tight - no dust can enter
Protection from water
The second digit is about resistance to liquids and is rated on a scale of 0 to 8.
- 0: No protection from liquids
- 1: Dripping water for 10 minutes
- 2: Dripping water when tilted at 15 degrees for 2.5 minutes
- 3: Spraying water for a minute at a rate of 10 litres per minute at a pressure of 50–150 kPa
- 4: Splashing of water
- 5: Water jets at a rate of 12.5 litres per minute at a pressure: 30 kPa at distance of 3 m for 15 minutes
- 6: Powerful water jets at a rate of 100 litres per minute at a pressure: 100 kPa at distance of 3 m for 15 minutes
- 7: Immersion in water up to 1m in depth for 30 minutes
- 8: Immersion in water up of 1m or more in depth for 30 minutes
For example, the Samsung Galaxy S9 is rated at IP68. That means it is dust tight and can be immersed in 1m or more of water for half an hour.
There are also categories 6K and 9K which go beyond the core of the rating system adding increased water pressure to some of the tests.
Now, if you're looking for a gadget that can handle some rough and tumble, you'll know what to look for on the spec sheet.