LED Testing and Laser Testing
THIS ARTICLE IS DESIGNED TO ANSWER THE FOLLOWING QUESTIONS.
- Which standard do I use to test an LED?
- Which standard do I use to test a laser?
- Which standard do I use to test a lamp or light?
This is the situation and how it came about
Lasers and LEDs have been classified according to their hazard since the 1970’s in the standard IEC 825 (later IEC 60825).
The standard governing the safety of laser products (IEC/EN 60825-1) was substantially revised and the classification system was overhauled in 2001 in Europe (EN) and internationally (IEC). This resulted in the addition of three new classes (1M, 2M, and 3R) and the elimination of Class 3A, and the standard now applies equally to lasers and LEDs.
The distance for the magnifier measurement condition (Condition 2) in 60825-1:2001 ranges from 14 mm to 100 mm and is determined by the light’s apparent source size.
LEDs were incorporated into IEC 62471-1:2005 “Photobiological safety of lamps and lamp systems” in 2005. This standard’s measurement conditions were set at 200 mm with varying fields of view based on risk group.
IEC 60825-1 was revised again in 2007, with the removal of most LEDs from being tested under the same standard as Lasers and a change to Condition 2, which means the magnifier condition is now fixed at 70mm within the retinal hazard region.
Because 60825-1(2001) was the last standard to implicitly apply to LEDs, it is often still used to evaluate LEDs as it is the most restrictive due to the possibility of a short measuring distance. Furthermore, other standards and directives, most notably the Electric Toys Standard, still refer to this version of the standard.
The most recent version of the standard was released in 2014. This revised how pulse lasers were handled, as well as introducing the new Class 1C; additionally, the Condition 2 measurement of 70 mm was removed, and the Naked Eye condition (condition 3) at 100 mm is now the closest distance for measurement.
However, because IEC 60825-2 “Safety of optical fiber communication systems (OFCS)” has not yet been updated, it retains a condition 2 measurement of 70 mm, and products used in Optical fibre systems must still be evaluated to IEC 60825-1 (2007).
Furthermore, IEC 60825-1:2014 allows for the testing of lasers under IEC 62471 if they are used in the same circumstances as conventional lamps.
TO DECIDE WHICH LED STANDARD, LASER STANDARD OR LAMP STANDARD YOU SHOULD USE, PLEASE USE THE FOLLOWING FLOWCHART.