Demystifying Ingress Protection

Rugged tablet computers, which must resist water and dust, are often ranked by ingress protection (IP) ratings which specify the environmental protection provided by an electronic enclosure. The IP rating has two numbers: the first indicates the levels of protection that the enclosure provides against the ingress of solid foreign objects, including dust; the second characterizes protection against the ingress of water.

The elimination of a fan for the purpose of cooling internal components is one strategy to ensure continued function in the presence of water and dust.