EN 170 defines the transmittance requirements for filters protecting against ultraviolet radiation. They are needed wherever there is a UV source: curing lamps, germicidal lighting, photopolymerisation, tanning equipment.
Marking
- 2-1.2 … 2-5
- UV filter, colour recognition may be affected
- 3-1.2 … 3-5
- UV filter with good colour recognition
The prefix is followed by a shade number from 1.2 to 5; the higher the number the darker the filter. Where the task requires colour discrimination — wiring work or signal recognition, say — a filter starting with 3 should be chosen.
