How Do Glass HMIs Become Robust?

The IP rating describes how well a device is protected against the ingress of solid objects (e.g. dust, dirt) and liquids (e.g. water).

An IP rating consists of two digits, for example IP65:

The first digit indicates protection against solid objects

The second digit indicates protection against water

Example: IP65 = dust-tight (6) and protected against water jets (5)

The protection class defines the electrical safety of a device and how it is protected against electric shock. It is fundamentally different from the IP rating.

The most important protection classes are:

• Protection Class I:Devices with protective earth connection (grounded), Examples: refrigerators, electric stoves, washing machines
• Protection Class II: Devices with double or reinforced insulation, Examples: power tools, personal care devices
• Protection Class III: Devices operated with extra-low voltage (SELV), Examples: medical devices, industrial equipment, devices used in wet environments or toys

IP Protection Class Quelle: Wikipedia

The Difference at a Glance

While the IP rating describes protection against environmental influences such as dust and water, the protection class defines electrical safety.

Both systems complement each other and are essential for safe operation and product certification.

Why This Distinction Matters

In practice, IP rating and protection class are often confused – which can lead to serious risks.

A device may have a high IP rating but still be unsafe if it lacks proper electrical protection. Conversely, strong electrical insulation does not protect against moisture ingress.

???? Only the combination of both ensures maximum safety and reliability.

Relevance for Custom HMI Development

In HMI development, IP rating and protection class are key design parameters and often defined as core requirements in project specifications.

They influence:

• Safety and compliance
• Design flexibility
• Material selection
• Manufacturing costs

Building & Building Automation

HMI systems in buildings must withstand moisture, cleaning agents, and temperature fluctuations.

Typical requirements:

• IP54–IP65 for splash protection
• Protection Class II for non-grounded devices
• Glass surfaces for hygiene and design

Incorrect specifications can lead to moisture damage or system failures, for example in smart home controls.

Industrial Applications

In industrial environments, HMIs are exposed to dust, oil mist, and cleaning processes.

Typical requirements:

• IP65 to IP69K
• Protection Class I
• High resistance to impact and chemicals

These factors are essential to ensure reliable operation in production environments

Medical Technology

Medical applications are subject to strict standards such as IEC 60601.

Requirements include:

• Easy-to-clean and disinfectable surfaces
• High electrical safety
• IP65 or higher
• Protection Class II or III

Capacitive glass surfaces reduce contamination risks and improve hygiene.