From the perspective of safety level, light curtains are: Class B, Class 1, Class 2, Class 3, Class 4

Class B: The most basic technology is used in the design to ensure its reliability. No security technology is used. Any failure will result in the loss of the safety function.

Level 1: Assured safety equipment and techniques are used to ensure the safety performance of the product, and the probability of loss of safety functions is less than that of Level B. Safety performance depends on the components and the adopted safety principles, reliable components and technologies.

Level 2: Meet safety requirements through regular self-inspection. A fault may result in the loss of the safety function, but it can be detected in the next duty cycle.

Level 3: Using guaranteed safety equipment and technology, failures do not result in loss of safety function, but accumulation of failures may result in loss of safety function.

Level 4: Using guaranteed safety equipment and technology, failure will not result in loss of safety function and safety function will always be present.