IP Rating Scale Explained
The IP rating scale, defined by the international standard IEC 60529, is a two digit code that describes how well an enclosure resists solids and liquids. The first digit rates protection against solid objects and dust on a scale from zero to six, and the second digit rates protection against water on a scale from zero to nine. A higher digit indicates greater protection.
Key Takeaways
An IP rating uses two digits to describe protection against solids and liquids.
The first digit covers solid objects and dust, rated from zero to six.
The second digit covers water, rated from zero to nine.
A higher digit means greater protection, and the letter X means a level was not tested.
The first digit ranges from zero, meaning no protection, to six, meaning completely dust tight. Intermediate levels cover protection against objects of decreasing size, with five meaning dust protected, allowing limited harmless ingress, and six meaning no dust ingress at all.
The second digit ranges from zero to nine. Lower levels cover dripping and spraying water, levels five and six cover water jets of increasing force, levels seven and eight cover temporary and continuous immersion, and level nine covers high pressure, high temperature water jets used in industrial cleaning.
An IP rating describes ingress protection only. It is often quoted alongside an IK rating for impact resistance, and in North America the NEMA enclosure system serves a comparable purpose for ingress.
Frequently Asked Questions
The first digit rates protection against solids and dust from zero to six, and the second rates protection against water from zero to nine.
It means the missing characteristic, in this case solids protection, was not tested or rated.
For everyday reference the strongest common ratings are IP68 for immersion and IP69K for high pressure, high temperature jets.
The international standard IEC 60529, known in Europe as EN 60529.
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