IP65 and IP67 are IEC 60529 ingress protection ratings describing how well an enclosure keeps out dust and water. Both are fully dust-tight (first digit 6); the difference is the second digit: IP65 is tested against water jets from any direction, while IP67 is tested against temporary immersion at a depth of 1 metre for 30 minutes.
Specify IP65/IP66 for equipment that is hosed down or exposed to driving rain, IP67 for equipment that may end up submerged, and a dual rating such as IP65/IP67 where both risks exist.
What actually happens on site
A standard office PC or consumer tablet is placed next to a production line. For the first few weeks, all is well. Then flour, sawdust or metal particles work their way through the ventilation slots, the fan clogs and the unit overheats.
The cleaning crew hoses down the line and water finds its way into a connector. A card reader at a construction site entrance faces condensation in winter and direct sun in summer. The fault log says "device failed"; the real cause is the wrong protection rating.
The same mistake is often made at the purchasing stage. A datasheet says "water resistant" or "IP67", and the buyer assumes the device is suitable for any wet environment. But an IP code is not a marketing label; it is the result of a specific test. Choosing without knowing which test was passed leads either to an over-specified, expensive enclosure or to equipment that fails early.
How to read an IP rating (IP rating chart)
The IP (Ingress Protection) code has two digits. The first covers solid objects and dust; the second covers water. If a digit was not tested, it is replaced with an "X" — IPX7, for example, tells you only that the water test was performed.
| Digit | Value | Meaning |
|---|---|---|
| First (dust) | 5 | Dust-protected: some dust may enter, but not enough to interfere with safe operation |
| First (dust) | 6 | Dust-tight: no dust enters during a pressurised dust-chamber test |
| Second (water) | 4 | Protected against splashing water from any direction |
| Second (water) | 5 | Protected against water jets from a nozzle |
| Second (water) | 6 | Protected against powerful water jets |
| Second (water) | 7 | Protected against temporary immersion up to 1 metre |
| Second (water) | 8 | Protected against continuous immersion beyond 1 metre, under conditions set by the manufacturer |
The test conditions are precisely defined. According to the IEC 60529 test summary published by the test laboratory Castle Compliance, the IPX5 test sprays the enclosure through a 6.3 mm nozzle at 12.5 litres per minute for at least 3 minutes; for IPX6 the nozzle grows to 12.5 mm and the flow to 100 litres per minute. In the IPX7 test the enclosure is immersed for 30 minutes, with its lowest point 1 metre below the surface. The IP6X dust test is carried out in a chamber filled with talcum powder while the enclosure is held under negative pressure.
IP65 vs IP67: jets and immersion are separate tests
The most common misconception is that IP67 "includes" IP65. Up to 6, the water ratings are cumulative; 7 and 8 measure a different risk. Immersion tests slow, steady water pressure; jet tests measure high-velocity water striking the seal. An enclosure that stays dry when submerged may still leak when a jet is aimed directly at its gasket.
That is why equipment that is both washed down and at risk of falling into standing water needs to pass both tests. Datasheets show this with a dual marking: IP65/IP67 or IP66/IP67. A device marked only "IP67" may not be the right choice for a food line that is hosed down every shift.
A further special class is IP69K, defined for high-pressure, high-temperature washdown and common in food, beverage and pharmaceutical production. Where hygiene cleaning uses pressurised hot water, an IP65 enclosure should not be considered sufficient. Terminals in these areas are often where digital HACCP and food traceability records are entered, so a leaking enclosure breaks the record chain as well as the device.
Why protection ratings matter more every year
The number of electronic devices installed in the field is growing fast. IoT Analytics' State of IoT 2025 expects the number of connected IoT devices to grow 14% to 21.1 billion in 2025 and to reach 39 billion by 2030. Many of these devices do not sit in an air-conditioned office; they work on production lines, in warehouses, car parks, fields and at site gates.
According to Eurostat's "Use of Internet of Things in enterprises", 29% of EU enterprises with 10 or more employees used IoT devices or systems in 2021; of these, 72% used them to secure their premises and 24% for condition-based maintenance.
Premises security and condition monitoring are exactly the applications where devices are mounted outdoors (a licence plate recognition camera at a car park entrance, for example), at gates or next to machines (such as predictive maintenance sensors). As device numbers grow, one wrong enclosure choice becomes a failure pattern repeated across dozens of locations. And the cost of a failure is not just the device itself: lost data, a lorry waiting at the gate or a production shift with no records all add up.
A six-step framework for choosing the right rating
- See the environment in person. Do not pick a rating until you have noted the type of dust (flour, sawdust, cement, metal), the source of water (rain, splashes, hose, pressure washing, pooling) and the temperature range.
- Work out how water reaches the device. Does it fall from above, spray from the side, or could the device be submerged? Jets call for 5–6, immersion for 7–8; if both apply, you need a dual rating. Devices constantly exposed to irrigation water and mud, such as a soil moisture sensor buried in a field (precision agriculture with soil sensors), call for IP67 or above.
- Ask about the cleaning procedure. If hygiene washing uses pressurised hot water, IP69K comes into play; if chemical detergents are used, gasket and enclosure materials need separate assessment. Sensors in vehicles whose bodies are washed regularly (as in reefer truck temperature monitoring) must also withstand that washing and constant vibration.
- Don't forget cable entries and connectors. An IP67 enclosure is only IP67 as installed. The wrong cable gland, an entry pointing upwards instead of downwards, or a USB cover left open cancels the protection.
- Treat condensation as a separate risk. A fully sealed enclosure can trap moisture as temperatures swing between day and night. For outdoor equipment, a pressure-equalisation membrane and sound thermal design matter as much as the IP rating. At remotely monitored sites such as pump stations, this detail directly sets how many repair visits you make.
- Assess impact and vandalism separately. The IP code says nothing about impact resistance. For devices in public areas, tempered glass and an impact rating (IK code) should be specified on their own terms.
The table below is a starting point only; the final decision depends on site conditions.
| Location | Typical risk | Starting rating to look for |
|---|---|---|
| Indoor office, reception | Light dust | IP20–IP40 |
| Production line, warehouse | Dust, occasional splashes | IP54–IP65 |
| Site gate, car park, façade | Rain, wind-driven water, dust | IP65–IP66 |
| Food line, hosed-down area | Water jets, detergents | IP66, IP69K where needed |
| Pit, pump station where water can pool | Temporary immersion | IP67; IP68 for continuous immersion |
Greenhouses are one of the toughest tests for an enclosure rating: high humidity, fogging and fertiliser and crop-protection vapours all attack panels and sensor housings. We cover equipment choice in our guide to smart greenhouse automation.
How we approach this at Digital Bridge
We select or design field equipment starting from the conditions where it will be used, not from a catalogue. Across our industrial products, the electronics, enclosure and embedded software are developed by the same team, so the protection rating is a design decision made on day one rather than a label added at the end.
- Environment analysis. On industrial data terminal projects we visit the site to see where the device will operate, how often it will be used and who will use it; protection rating, screen size and reader type are chosen accordingly. The technical feasibility study for hardware is free of charge.
- Enclosure and seal design. An IP-protected enclosure against dust and water, components suited to the industrial temperature range and vibration-resistant mounting — with a glove-operable touchscreen where needed.
- Readers built into the housing. Barcode, QR, RFID or fingerprint readers are integrated inside the enclosure, so dangling cables and separate handheld scanners stop being weak points in the seal.
- Prototypes tested at the real workstation. Each prototype is trialled at the actual station and refined with operator feedback before series production. Because design and manufacturing happen under one roof, we can build custom devices even in single-digit quantities.
The same approach applies to our other outdoor equipment: the outdoor models of our self-service kiosk terminals are built to IP54 or above (see our self-service kiosk guide for where kiosks earn their keep), with the exact level set by the rain, sun and dust on site. Outdoor digital signage screens need the same care: alongside high brightness, the enclosure must keep out dust and rain. On card access control projects we likewise choose card readers, turnstiles and barriers to suit your site, while our own product SmartPass runs the software side: a single card read opens the door, records attendance and deducts the canteen meal.
How a device sends its data from the field is as important a design choice as its enclosure. We compare connectivity options in LoRa vs NB-IoT vs cellular and walk through the path from idea to series production in our IoT device development process guide. For other field-device decisions, browse the full IoT & Hardware hub.
Next step
Start with a simple inventory: for every device on site, record its location, the type of dust and water it faces, how it is cleaned and why it failed over the past year. If failures repeat at the same spot or in the same kind of environment, the protection rating is the likely culprit. Then get in touch with that list; we will review the site with you and recommend the right rating — or an enclosure designed around it.