IP stands for ‘ingress protection’ and is usually assigned to enclosures and in industrial computers this is the enclosure that houses the PC. IP defines how much protection the enclosure can offer in protecting the device, in this case an industrial computer, from penetration of foreign bodies.
IP ratings where established by the IEC (International Electrotechnical Commission) under guidance from CENELEC (European Committee for Electrotechnical Standardization) as a way of providing guidance and standardization to enclosures, however, IP ratings are now used throughout the electrical industry denoting the protection afforded by all types of seals.
The IP rating comes in the form of digits, the first denotes the level of protection the enclosure offers against foreign bodies such as dust or dirt; the second digit denotes how protection the enclosure offers against water.
To examine the effectiveness of enclosures it is best to look at two of the most common IP ratings. IP54 is often used for enclosure in warehouse or factory conditions. The IP rating of 5 (first digit) suggests the enclosure will protect extremely well against dust, although not entirely dust tight, it will dust will ensure only a minimal amount of dust enters the unit and not enough to inhibit the device. The second digit 4 suggests the IP54 enlcosure will also offer protection against the splashing of water although it will not guarantee protection from water jets or immersion.
IP65 is another common IP rating used in industrial computers. This IP rating offers dust tight protection (first digit 6) whilst the second digit (5) suggests the unit will protect against hose-down and water jets. For this reason IP65 enclosures are often used in the food manufacturing and production industries or other sectors where there is liberal use of water.