Lighting distance

This is the distance at which a headlamp illuminates greater than 0.25 lux. For headlamps equipped with standard batteries, lighting distance decreases progressively as the energy source is drained. To accurately represent this decrease, lighting distance is measured beginning with new batteries (maximum capacity for the headlamp):

• After 30 minutes of use (normal use)
• After 10 hours of use (continuous use through one night)
• After 30 hours of use

 

Petzl has also created a reference scale for being seen.
For a signaling light, the limit for being seen has been established at 0.00001 lux at 100 m away.

Regulated headlamps
Some headlamps are equipped with an electronic regulating mechanism that maintains a relatively stable lighting distance during most of the life cycle with both regular and rechargeable batteries. Once the available electric energy is no longer sufficient, the regulation automatically stops. The light level automatically decreases to a minimum survival level of light. Leaving the user with enough time to change the batteries.
For this type of headlamp, Petzl states the lighting distance obtained during the regulated lighting phase.


 

Duration / Burn time

Light duration is defined as the length of time that a headlamp illuminates at 0.25 lux or more from a distance of two meters.
When the light produced is lower than this level, we consider that the headlamp is no longer usable, whether for walking, reading, or any other activity. To measure this, the lamp is equipped with a set of new or fully charged batteries. The lamp is switched on, and we measure the time it takes for the light to diminish to below 0.25 lux.

Special case: regulated LED headlamps
The light duration measurement equals the regulated lighting duration plus the length of time that the light remains above 0.25 lux at 2 m (reserve power mode). This figure is consistently associated with the corresponding lighting distance.



Special case: signal lighting
According to.the reference scale for being seen with a signal light, Petzl considers that visibility less than 100 m is insufficient for being seen and ensuring safety. The SiGNAL is no longer considered visible after 40 hours of use in constant lighting mode or after 120 hours of use in flashing mode.