Laser Welding Helmets FAQs
Plain answers on how laser welding helmets differ from arc helmets, what the laser markings mean and how to use them safely.
How is a laser welding helmet different from an ordinary welding helmet?

An ordinary welding filter is designed for the ultraviolet, visible and infrared light of an arc. A laser welding helmet adds a filter tested for laser radiation, typically marked to the European laser eye protection standard, which blocks the wavelength your laser produces.
Some designs use a laser filter alone, and others combine it with an auto-darkening filter for arc welding as well. The marking on the filter tells you which wavelengths and laser modes it covers. Always check that the helmet matches your laser before use, and follow the manual.
What do the letters D, I, R, M and LB on the filter mean?

These markings show which laser modes and power levels the filter was tested for. The letters give the operating mode: D for continuous wave, I for long pulses, R for short (giant) pulses and M for very short, mode-locked pulses. LB is followed by a number showing the protection level, and each step up is ten times higher.
A typical marking lists a wavelength range, then the modes and levels, such as D LB7 for continuous wave. A pulsed laser needs a rating for the pulse mode as well as for continuous wave. The numbers must be compared with your laser's power, beam size and pulse details, so check them against the laser's data.
What is the difference between laser protection ratings for full protection and alignment?

The European standard for full laser protection covers eyewear tested against direct hits, so it is the rating to look for when working with a welding laser. A separate alignment standard covers visible beams only. It reduces the beam to a level that lets a technician see the spot while adjusting, and it does not cover infrared or ultraviolet beams.
Most welding lasers work in the invisible infrared, so alignment-only eyewear is not suitable for welding. Check the marking on the helmet filter shows full protection for your laser's wavelength.
Do I still need laser safety eyewear under the helmet?

It depends on the equipment and the risk assessment, but laser makers often require both. Some laser welding systems instruct everyone present to wear their laser welding helmet and also laser safety eyewear of a stated protection level for the laser's wavelength. The helmet guards against sparks, intense light, ultraviolet and stray laser radiation.
Read the manual of your laser system and follow its labelled requirements. Anyone else in the work area may need protection too.