Statistical distribution of protection times of passive laser safety barriers - normal distribution or is there a better discription?

Recent developments in laser material processing technology, like the rapid increase of maximum output power, the remarkable improvement of the beam quality, and the availability of deflection optics, have put a focus on laser safety technology. Moreover, the development of new application fields, such as processing of CFRP, has led to a higher demand for laser technology, and an increased need for suitable safety technology. The protective exposure limit (PEL) according to IEC 60825-4 is currently calculated based on the assumption that protection times are normally distributed. This approach is criticised for generating too low protection times and for not reflecting the reality. Thus, the question arises whether there is a better way to describe the distribution of protection times for a more accurate calculation of the PEL. The aim of this work was to take the first step to answer this question by executing protection time tests, using steel plates and a fibre laser, and to determine the statistical distribution. In the following, random based protection time calculations were executed by the aid of the resulting distributions. Thisnormativeprocedurewas opposed toan alternative method,and the results were compared.It could be demonstrated, that both approaches lead to similar results for the examined case.     «

Recent developments in laser material processing technology, like the rapid increase of maximum output power, the remarkable improvement of the beam quality, and the availability of deflection optics, have put a focus on laser safety technology. Moreover, the development of new application fields, such as processing of CFRP, has led to a higher demand for laser technology, and an increased need for suitable safety technology. The protective exposure limit (PEL) according to IEC 60825-4 is cu...     »