The IP Code
The IP Code or International Protection Rating consists of the letters IP followed by two digits and an optional letter. It classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures. The standard aims to provide users more detailed information than vague marketing terms such as waterproof.
The first digit indicates the level of protection that the enclosure provides against access to hazardous parts.
The second digit deals with the protection of the equipment inside the enclosure against harmful ingress of water.
Below is an easy to follow reference chart to help you decide which IP rating you need or have.
Protection against dust
Protection against water
|0: No protection
||0: No protection
|1: Protection against solids up to 50 mm
||1: Protected against dripping water
|2: Protection against solids up to 12 mm
||2: Protected against dripping water (tilted)
|3: Protection against solids up to 2.5 mm
||3: Protected against water spray
|4: Protection against solids up to 1 mm
||4: Protected against splashing water
|5: Protection against dust; limited ingress
||5: Protected against water jets
|6: Totally protected against dust
||6: Protected against a nozzle under pressure
||7: Protected against immersion (1 meter for 30 min)
||8: Protected against submersion (at depth, under pressure)
Most manufacturers have devices that are totally protected against dust and thus have the first digit as “6”. The second digit of the IP rating is where things get interesting.
The second digit in a typical IP code indicates a precise level of protection against moisture ingress under specific test scenarios. The ratings widely accepted as ‘waterproof’ for most general purposes are IP65, IP66 and IP67. However, one common misconception regarding weatherproofing is that items intended for prolonged outdoor use require the highest numerical IP ratings for moisture resistance.
This isn’t always the case since most rainwater – even in windy conditions – tends to fall relatively close to vertical, and under very low pressure.
In addition, it isn’t strictly accurate to think of IP ratings for water resistance as being ‘higher’ beyond IPX6: be aware that IPX7, IPX8 and IPX9 are codes specifically addressing immersion properties, and that items certified at these ratings need not necessarily meet the criteria for pressurised water jet resistance denoted by IPX5 and IPX6.
IP67 or IP68 signifies protection against actual immersion in water. There’s a significant engineering leap—usually requiring additional product cost—needed to move a device from IP65 to IP67. For the most part, devices aren’t certified to IP66, since IP66 standards require near IP67-level sealing. If they need IP66, manufacturers usually just go ahead for full IP67 testing.
Some customers though, do require a device to be capable of withstanding immersion. Foresters, Land Surveyors, technicians and scientists working in marine environment, all might see their devices accidentally submerged on occasion. For them, IP67 makes sense.
So what about IP68 then? The standard for IP68 requires that the manufacturer specify the time and depth of the immersion test. IP67 is one meter for 30 minutes. IP68 needs to be more than that, but it is up to the manufacturer to designate exactly how much longer/deeper their devices were tested. Be sure to ask for that time and depth to understand the extra benefit that you are actually getting.