IP Ratings

“IP” (Ingress Protection) ratings are defined by the International Electrotechnical Commission in their IEC 60529 Standard. This rating classifies “… degrees of protection provided by enclosures for electrical equipment with a rated voltage not exceeding 72, 5 kV.”  (IEC standard 60529 as well as DIN EN 60529; VDE 0470-1:2000-09)

Typically, IP ratings are followed by two numbers. The first number refers to the protection against solid objects, usually dust. The second number refers to protection against water.  The numbers have specific definitions, which you can see below. For example, the roda Rocky have a rating of IP65, so that means “No ingress of dust; complete protection against contact,” and “Water projected by a nozzle against enclosure from any direction shall have no harmful effects.”

Industrial and military applications often require more ruggedness from their computers than traditional commercial enterprises. In these instances, military standards, such as MIL-STD 810 and MIL-STD 461 may be more significant.

First Number means:

Ingress  Protection  level 

Object size  protected against 

Effective against



No protection against contact and ingress of objects


>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


>12.5 mm

Fingers or similar objects


>2.5 mm

Tools, thick wires, etc.


>1 mm

Most wires, screws, etc.


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; complete protection against contact


Dust tight

No ingress of dust; complete protection against contact

Second number means:

Ingress   protection    Level  

Object size    protected against   

Effective against                                           


Not protected



Dripping water

Dripping water (vertically falling drops) shall have no harmful effect.


Dripping water when tilted up to 15°

Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position.


Spraying water

Water falling as a spray at any angle up to 60° from the vertical shall have no harmful effect.


Splashing water

Water splashing against the enclosure from any direction shall have no harmful effect.


Water jets

Water projected by a nozzle against enclosure from any direction shall have no harmful effects


Powerful water jets

Water projected in powerful jets against the enclosure from any direction shall have no harmful effects.


Immersion up to 1 meter

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).


Immersion beyond 1 meter

The equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer.
NOTE: Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that produces no harmful effects.