Fundamentals

IP66, IK10 and the rest: what the numbers on the housing mean

11 September 20262 min readcctvfinder

Almost every data sheet carries two codes that nobody looks up and everybody believes they know. They are quickly explained, and one of the two is read wrongly nearly every time.

IP: two digits, two questions

IP stands for International Protection. The first digit answers the question about solid objects, the second the one about water. They are to be read independently of each other.

First digit	Protection against
4	solid objects from 1 mm
5	dust in harmful quantity
6	dust entirely, dust tight

Second digit	Protection against
4	splashing water from any direction
5	water jets from a nozzle
6	powerful water jets
7	temporary immersion
8	continuous immersion

IP66 therefore means dust tight and protected against powerful water jets. For a camera on an exterior wall that is the usual and sufficient rating.

The mistake almost everyone makes

The second digit is not a ranking that includes everything below it. From 7 upwards the test changes method: it tests against immersion, meaning still water under pressure, and no longer against a jet.

A housing rated IP67 therefore does not automatically carry the protection of IP66. A seal that holds still water can still be defeated by a high-pressure jet at close range. This is why careful manufacturers print both.

If the data sheet says IP66/IP67, that is not hesitation but the more precise statement. If it only says IP67, the question about water jets is unanswered.

It becomes practical at cleaning time. Anyone hosing down a hall or a yard with a pressure washer needs the 6 in second place. It is also the most common reason cameras start drawing moisture after a year or two.

IK: impacts in joules

IK under EN 62262 says what impact energy the housing withstands. The number is not a scale from one to ten but stands for a measured value in joules.

Level	Impact energy	roughly equivalent to
IK06	1 J	a knock in passing
IK07	2 J	a thrown stone
IK08	5 J	a hard kick
IK09	10 J	a blow with a tool
IK10	20 J	a deliberate hammer blow

Between IK08 and IK10 lies a factor of four, not two steps. Where vandalism is to be expected, meaning entrances, underpasses and parking decks, IK10 is the rating to ask for.

What neither number tells you

Neither IP nor IK says anything about image quality, temperature limits or the life of the seal. An IP66 housing with a poor lens delivers a poor image in any weather.

The rating decides whether the camera survives. Whether it delivers anything usable is decided by the calculation beforehand: distance, mounting height, field of view, resolution.