Ingress Protection

When you read about the details of any smartphone, you’ll come across IP67, IP68, or similar. Have you ever wondered what that means or how it might help you? And what does it matter whether it says IP67 or IP68?

Today we’ll answer these questions and more.


What is an IP rating?

Ingress protection (IP) ratings represent levels of sealing for electrical housings against foreign bodies such as dirt and water. The International Electrotechnical Commission (IEC) developed these ratings and set the standard of EN 60529 (British BS EN 60529:1992, European IEC 60509:1989).

Why does an IP rating matter?

Because liquids and other contaminants can ruin electronic circuits. So water resistance and waterproofing have become prominent features in smartphones and other electronic devices.

A device installed in the field may face extreme conditions like thunderstorms, sudden temperature changes, and constant exposure to the elements. And these conditions can erode housings and destroy or distort readings.

For example, dust can build up in sockets, ports, and cases, forming a layer that causes circuits to overheat. If dust coats surfaces in relays or switches, then they may perform poorly or not perform at all. And moisture can cause short circuits or corrosion, conditions which also affect the performance of the device.

How do you read an IP rating?

Okay, an IP rating has two numbers. The first refers to the degree of protection against solid objects, and the second against liquids. This table will show you what each means.

IP Rating Reference Chart

(Courtesy of

First Digit Description Second Digit Description
0 Not protected 0 Not protected
1 Protected against objects > 50 mm 1 Protected against drips
2 Protected against objects > 12.5 mm 2 Protected against drips if the
housing tilts up to 15°
3 Protected against objects > 2.5 mm 3 Protected against sprayed water
4 Protected against objects > 1.0 mm 4 Protected against splashing water
5 Dust-protected 4K Protected against splashing water at increased pressure
6 Dust-tight 5 Protected against water jets
6 Protected against powerful water jets
6K Protected against powerful jets at increased pressure
7 Protected against temporary immersion in water
8 Protected against permanent immersion in water
9K Protected against water during high-pressure or high temperature spray downs (steam cleaning)

For example, IP2X means protected against objects larger than 12.5 millimeters. You’ll see this rating on devices for indoor use, like standard wall sockets. So IP2X means you can’t stick your fingers in the holes. And a DIN-rail temperature transmitter installed in a control room should not need much protection against water or dust, so IP2X would work here too.

But a device with an IP45 rating will have protection against objects larger than one millimeter and water jets. So what about the ratings you often see on smartphones, IP67 and IP68?


IP67 vs. IP68

IP67 means water-resistant and IP68 means waterproof.  And what do those terms mean? An IP67 device can sit in water up to a meter deep for half an hour and should still work.

But beyond that, you have no guarantee. However, IP68 guarantees protection in deeper water for longer, as specified by the manufacturer. And both resist dust.

Some examples can be  considered as follows:

EcoMeter P : Ultrasonic Level transmitter with IP67 protection

Cerabar PMC21 : Pressure transmitter with IP68 protection

What does IP69K mean?

IP69K, the highest rating, protects against dust and high-pressure, high-temperature water, like for steam cleaning. You’ll find this rating on devices for hygienic processes. Why? Because the food and beverage industry regularly steam-cleans every surface that comes in contact with food to prevent contamination. Therefore, devices must have the IP69K rating for these processes.


Ingress protection prevents dust and water from damaging devices or hampering their performance. Such issues can include short circuits, corrosion, and signal interference. So IP ratings can tell you which device will best withstand the conditions in your specific process.


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