1. The Scope of EN 207: Complete Protection
The European standard EN 207 governs personal eye-protection equipment against laser radiation. Unlike simple optical filtering, EN 207 mandates that both the filter lens and the frame withstand direct beam irradiation under standardized testing conditions without losing structural integrity or allowing dangerous transmitted radiation.
Damage Threshold Testing Conditions
Under EN 207, protective filters and frames are subjected to standard test pulses: either 5 seconds of continuous wave (CW) exposure or 50 pulses for pulsed systems. The material must not crack, melt, or transmit radiation in excess of the specified scale number (LB rating).
Laser Operation Modes in EN 207
- D (Continuous Wave): Pulse duration > 0.25 s
- I (Pulsed Mode): Pulse duration > 1 μs to 0.25 s
- R (Giant Pulsed / Q-switched): Pulse duration > 1 ns to 1 μs
- M (Mode-locked / Ultrashort): Pulse duration < 1 ns (femtosecond / picosecond)
2. The Scope of EN 208: Laser Alignment Eyewear
EN 208 covers eyewear specifically designed for laser adjustment and alignment work. In alignment tasks, personnel must visually observe the beam spot. Therefore, total attenuation would render the beam invisible and impede work.
EN 208 filters attenuate visible laser light (400 nm to 700 nm) so that the transmitted power matches Class 2 laser safety limits (< 1 mW). An EN 208 rating is denoted by RB numbers (e.g., RB 1 to RB 5), designating the maximum incident power or energy that is safely reduced to Class 2 levels.
3. Marking Formats and Practical Selection
A compliant EN 207 marking contains the wavelength, laser mode, LB scale number, manufacturer symbol, and mechanical strength class (e.g., 1064 D LB6 + IR LB7 X CE). Always ensure that the laser's operational parameters—pulse duration, repetition rate, and beam power density—are matched against the certified LB level.