Master of optics

Kristina Magnusson has long been fascinated by optics. And for the past 25 years, she has been applying this interest to helping improve the safety, quality and visual performance of 3M™ Speedglas™ Welding Helmets.

A Senior Optics Specialist with 3M, Kristina Magnusson found her calling when she was still at school. “I wasn’t really interested in school,” she says. “But when I started studying light rays and lenses I found that this was an area that I easily understood compared to others in my class.”

150211 3M Gagnef Kristina Magnusson Foto Hasse Eriksson

Magnusson went on to earn a master’s degree in engineering physics, focusing on the field of optics. She then got involved in a summer project for Speedglas products to develop a test instrument for measuring the light diffusion of welding filters. She hasn’t looked back since.

Today, Magnusson is one of a four-strong optics team at 3M Welding Centre of Excellence in Gagnef, Sweden. She specialises in designing and adapting optical parts for

Speedglas welding helmets. These include the welding filter and its components such as interference filter, liquid crystal cells and polarizers.


3M manufactures many of its own Speedglas welding filter components, including liquid crystal cells and interference filters, which Magnusson mentions as a great advantage. “By having this connection to manufacturing we can easily test and transfer new technology,” she adds. “That helps us get a better understanding and control of the entire process.”

Liquid crystal cells are probably best known for their use in liquid crystal display (LCD) screens. 3M mainly uses the cells to manipulate the light in the Speedglas welding filters, with the liquid crystal molecules sandwiched between two glass substrates in the welding lens. “When you change the orientation of the liquid crystal molecules you can change the amount of light that will be absorbed by the polarizer,” Magnusson says. “This helps reduce the glare generated from welding.”

Focus on safety

The 3M optics team also works on improving things such as how much colour can be seen through the welding filters. Of course, safety is a prime consideration when it comes to welding products. Magnusson is leading an international ISO task group made up of experts focusing on automatic welding filters, within eye and face protection standards.

“I’m very much involved in the standardization of eye protection,” she says. “We need to make sure that the welding helmets help provide protection against radiation and the ISO group takes all aspects of this into account when establishing standards.”

3M wants to improve optical quality even further to support welders in their work. For example, an optical solution that diminishes the glare from welding fumes or reflections. “You never know what new technologies will bring,” Magnusson says with enthusiasm.

150211 3M Gagnef Kristina Magnusson Foto Hasse Eriksson

NAME: Kristina Magnusson

TITLE: Senior Optics Specialist, 3M Personal Safety Division Welding, Global Centre of Excellence

HOME: Sweden

HOBBIES: Downhill skiing, snowboarding, golf, spending time at her cottage in the mountains and reading up on developments and new technologies in optics.

AUTHOR: Wrote Ljus och LCD-teknik (Ekelund, 1998), a book about LCD technology and its applications.

Twenty years of optical improvements of Speedglas auto-darkening filters3m_speedglas_9100xxi_auto-darkening_filter_part_number-_500026

  • Higher transmittance in light state (from shade 4 to shade 3)
  • Lower light diffusion (from class 3 to class 1)
  • Improved uniformity of shade (from class 2 to class 1)
  • Improved refractive power (from class 2 to class 1)
  • Reduced switching time from light to dark (now 0.1 millisecond at room temperature)
  • Improved durability (resistance to variations in temperature and humidity)
  • Improved angular dependence of shade
  • Lower weight of welding filter

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