Measurement procedure for the risk assessment of light emitting diodes (LEDs)
Light emitting diodes (LEDs) have in comparison with the conventional light sources a long lifetime and a high energy efficiency. In many applications they replace increasingly the conventional light sources. LEDs have been used in displays of measurement readings and operating states, in projection systems and in signalling, in pocket lamps, headlights in automotive industry as well as in general and architecture illumination. Great progress achieved recently in the LED technology lead to higher luminous efficacies and higher energetic ('bluer') spectra of LEDs. They can become thereby potentially dangerous for the human eye. Already 1993 LEDs were included in the scope of the Laser Safety Standard of the International Electrotechnical Commission (IEC) IEC 60825-1 and therefore, from the point of view of radiation protection, explicitly put on equal terms with lasers. However, shortly afterwards it has been realized that the former measuring procedure could lead to overcritical results for LEDs. Since, inspite of improvements in the measuring procedure, the application of the Laser Safety Standard stayed problematic, the responsible groups of the Techical Committee TC 76 of the IEC have decided to exclude LEDs from the scope of the Standard.
In the future, the Photobiological Lamp Safety Standard of the International Commission on Illumination (CIE), CIE S 009/E:2002, should be applied on LEDs. In the meantime, a computer-supported measuring procedure (Schulmeister, ILSC Conference Proceedings, Los Angeles, S. 91, 2005) has been developed, on the basis of which it is possible to carry out an accurate, but costly safety analysis of LEDs. In the current project an attempt will be undertaken to develope a simpler measuring procedure based on the Standard CIE S 009/E:2002 and to verify it through the comparison with results of the above mentioned measurement approach.
Unit 2.2 "Physical Agents"