IP Ratings: What Do They Mean?

You may have seen IP ratings when shopping for outdoor electronic gear like GPS units, headlamps, cameras and solar power devices. This very useful but sometimes mysterious rating system simply describes the ruggedness of your electronics. Wondering how much dirt or water your device can handle? An IP rating will tell you.

• What does an IP rating mean?
• Who assigns IP ratings?
• Understanding IP ratings
• The real nitty gritty
• The Takeaway

What does an IP rating mean?

IP means ‘International Protection’ although it’s often interpreted as ‘Ingress Protection’. In simple terms, it’s a standard way of measuring the ability of a device to resist damage from solid particles (for most of us, that’s dirt and dust) and liquids (again, most folks are worried about water).

Who decides?

When a manufacturer says a device is ‘waterproof’, does that mean (a) it’s protected from light rain or (b) you can go swimming with it? Likewise, does ‘dustproof’ mean a device is equally at home on Idaho backroads and in Saudi Arabian dust storms?

Groups of engineers and other detail-minded people like the International Organization for Standardization (ISO), the International Telecommunication Union (ITU) and the International Electrotechnical Commission (IEC) are unsatisfied with vague terms like ‘waterproof’ or ‘dustproof’.

Collectively, this community devised standardized, rigorous testing procedures to determine how well a device is sealed against liquids and solids (including certain insects – see IP4 in Table 1).

understanding IP rating labels

An IP Rating label usually looks like this:

The first digit reveals a device’s ability to keep out solid particles, like dust and dirt. Consulting Table 1 below, we see that this device is completely sealed against tiny dust particles.

The second digit indicates how well the device is protected against liquids. Consulting Table 2 below, we see that this device will still function after being submerged in water at a depth of up to 3 feet for 30 minutes.

In conclusion, this example rating indicates a very respectable ability to shrug off dust and water.

the takeaway

IP ratings come from the complex worlds of engineering design and rigorous laboratory testing, both of which are beyond the experience of most cell phone and headlamp users. But don’t worry – all you need to remember is that IP Ratings are a very useful way to judge just how tough your electronic gear actually is. Armed with this insider knowledge, you can go out and enjoy worry-free use of your backcountry gadgets.

The Real Nitty Gritty

Table 1 – The first digit of an IP rating

Level	Effective against objects of this size	Description
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, slender screws, large ants 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.

Table 2 – The second digit of an IP rating

Level	Effective Against	Description
1	Dripping water	Dripping water (vertically falling drops) shall have no harmful effect on the specimen when mounted in an upright position onto a turntable and rotated at 1 RPM for 10 minutes (equivalent to 1 mm rainfall per minute).
2	Dripping water when tilted at 15°	Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle of 15° from its normal position. A total of four positions are tested within two axes for 10 minutes total (equivalent to 3 mm rainfall per minute).
3	Spraying water	Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with a counterbalanced shield. Test a) is conducted for 5 minutes, then repeated with the specimen rotated horizontally by 90° for the second 5-minute test. Test b) is conducted (with shield in place) for 5 minutes minimum.
4	Splashing water	Water splashing against the enclosure from any direction shall have no harmful effect, utilizing either: a) an oscillating fixture, or b) A spray nozzle with no shield. Test a) is conducted for 10 minutes. Test b) is conducted (without shield) for 5 minutes minimum.
5	Water jets	Water projected by a nozzle (6.3 mm) against enclosure from any direction shall have no harmful effects. Conducted for 15 minutes at a water volume of 12.5 liters per minute and pressure of 30 kPa at 3m.
6	Powerful water jets	Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. Conducted for 3 minutes at a volume of 100 liters per minute at a pressure of 100 kPa at 3m.
7	Immersion up to 1 m depth	Ingress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion). Conducted for 30 minutes.
8	Immersion 1 m or more	The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects. The test depth and duration is expected to be greater than the requirements for IPx7, and other environmental effects may be added, such as temperature cycling before immersion.