Understanding IK ratings: How IK testing ensures HMI durability?

Definition and features of IK rating

 The IK rating defines the degree to which a product can resist impact forces and appears frequently in technical documents. Originally part of the IP sealing tests, the IK rating became its own distinct measure in 1995 under the EN 62-262 European standard. It specifically assesses the impact durability of materials used in human-machine interfaces (HMIs) like the anti-vandal pushbutton switches AV 250, which adhere to IK standards. Ratings range from IK00, indicating no protection, to IK10, which protects against impacts as severe as 20 joules—similar to a 5 kg mass dropped from 400 mm. Selecting HMIs with appropriate IK ratings ensures they can withstand the physical demands of their operating environments. 

Functioning of the IK impact test 

This rating can be decisive in a product selection. It doesn’t rate the mechanical life but the capacity of a product to face environmental aggressions. Therefore, it is a key feature for any product intended for consumer goods. The IK impact test is carried out using a “Charpy pendulum” impact tester. This device measures the resistance of a product submitted to 3 repeated identical impacts. The impact energy (in joules) depends on two elements:

• The distance between the hammer and the tested sample 
• The hammer weight. According to the resistance level rated during the test, an IK code is assigned to the product. This code ranging from IK0 to IK10, determines the energy level the product can absorb. 

Construction Machinery: In the demanding environment of construction sites, equipment is continually exposed to potential hazards such as falling objects, accidental impacts, and abrasive materials. For Human-Machine Interfaces (HMIs) operating in such conditions, a high IK rating isn’t just beneficial—it’s essential. Interfaces that meet the IK10 test criteria are built to maintain uninterrupted operation in these environments.

Material Handling: In material handling applications, such as in warehouses and logistics centers, HMIs are often installed on forklifts, cranes, and other handling equipment. These environments are prone to collisions, knocks, and other forms of mechanical stress. Products rated under an IK10 impact rating help ensure that control systems remain functional despite mechanical stress.

Defense: The defense sector demands HMIs that can perform reliably under the most extreme conditions, including combat environments where equipment may face intense impacts, vibrations, and shock. High IK-rated HMIs are essential in this field to ensure that mission-critical systems remain functional, regardless of the physical challenges they encounter. The robustness of these interfaces is vital for the safety and success of military operations. Only HMIs that undergo stringent IK testing can meet the reliability standards required in such critical applications.