When using (electronic) devices, the environmental conditions and external influences affecting the device must be observed. Is the device exposed to spray water, perhaps even immersed for a longer period of time or used in a dusty environment?
The IP protection class (IP = International Protection) shows you under which conditions you can use the device. An IP protection class cannot be specified by the manufacturer, but is tested by an independent testing laboratory.
There are different national and international standards for these tests. Even if the basic meaning of the protection classes is the same, the test specifications may differ in detail. The following article is based on DIN EN 60529 Schutzarten durch Gehäuse (engl.: Enclosure protection classes).
The code numbers
The degree of protection is always indicated by the letters IP followed by two numbers. It is possible that one of the numbers does not have to be specified. Then it has to be replaced by an x.
Optionally, DIN EN 60529 provides the option of attaching two code letters for more detailed explanations. The first letter in the third digit of the code stands for protection against access to dangerous active parts. The letter at the fourth position of the code indicates the test conditions. For example, it is possible to indicate whether moving parts were inspected while standstill or in operation or under specified water conditions. Please refer to the DIN EN 60529 for details on the code letters.
Protection against solid particle and contact
The first code number indicates the protection against solid particles and the protection against contact. A higher code number includes all lower ones.
|1. Code Number||Protection against solid particles||Protection against contact|
|0||No protection||No protection|
|1||Solid particles with diameter ≥ 50 mm||Protection against access with the back of the hand|
|2||Solid particles with diameter ≥ 12,5 mm||Protection against access with fingers|
|3||Solid particles with diameter ≥ 2,5 mm||Protection against access with tools|
|4||Solid particles with diameter ≥ 1 mm||Protection against access with wire|
|5||Dust in harmful quantity||Complete protection against contact|
|6||Dustproof||Complete protection against contact|
Protection against water
The second code number indicates the protection against water.
|2. Code Number||Protection against water|
|2||Falling dripping water; housing tilted up to 15°|
|3||Fallendes Sprühwasser bis 60° gegen die Senkrechte|
|4||Splash water from all sides|
|5||Water jets (nozzle) from any angle|
|6||Strong water jets|
|9||Water from high-pressure or steam jet cleaning|
It is important to note, that a protection class up to IPx6 automatically includes a lower protection class. For higher protection class this is not automatically the case. However, IPx8 automatically includes IPx7 because the specification requires longer and/or deeper immersion. While IPx7 is defined as 30-minute immersion at a depth of one meter, IPx8 always requires the duration and depth at which the device was tested.
All other test conditions (e.g. the definition of strong water jets) can be found in the respective standard.
A day in the test laboratory
To give you an insight into a day in the test laboratory, we have accompanied the BLE Gateway. It has been tested against the protection classes IP66 / IP68 / IP69. For the IP68 test it was submerged for 5 hours under one meter. All exams were passed successfully.
In the article “A heavy workday with the BLE Gateway in the test laboratory” we show you, including photos, how these tests were carried out.