Alerting – a question of passive perceptibility.
The "Alerting" category makes the greatest demands on the perceptibility of a signal. Fire alarms and other emergency situations require people in the covered area to react without any delay. Xenon technology has clear advantages in this case.
The extremely short light pulse of a xenon flash offers peak light intensities easily exceeding 100,000 cd which cannot be achieved with LEDs. Furthermore, xenon flashing lights emit omnidirectional light which is identical in every direction and avoids "optical gaps" in the coverage volume. This means both a wider coverage and better passive perception (i.e. a person's perception when their face is averted from the signaling device).
Looking at the energy consumption relative to the coverage volume, there is no significant difference from LED technology in terms of energy balance. Nevertheless, it is also possible to use flashing LED lights for alerting people. However, due to their light emission pattern they are preferably used for smaller areas or where the light signal is transmitted in just one direction.
What is signaled in the "Alert" category?
Examples:
• Limit values exceeded
• Abnormal processing status
• Danger to the environment
• Acute risk to health
• Danger to life and limb
• Collision
• Evacuation
