Dr. Tilman Weiss, sglux GmbH, Berlin, Germany

Technical Report « Where SiC can replace discontinued GaP? »

Abstract
For measurement applications with a peak radiation between 210 nm and 346 nm (e.g. UV sterilization lamp or combustion flame control) a SiC UV photodiode can replace a GaP photodiode without restrictions – it will even output a higher photocurrent. A SiC device irradiated with a peak radiation from 346 to 380 nm will output a lower photocurrent compared with GaP (at same active area). However, if the radiation intensity is high, e.g. curing applications at 365 nm the SiC’s current output will remain at a usable level.

Dr. Niklas Papathanasiou, sglux GmbH, Berlin, Germany
Tech Report 350°C

Abstract
sglux announces that a new high temperature stable SiC UV Photodiode is now available. The photodiode can be permanently operated at a temperature of 350°C.

G. Hopfenmüller, N. Papathanasiou, T. Weiss,
sglux GmbH, Berlin, Germany

Presentation on International Conference on UV LED Technologies & Applications 2018, Berlin, Germany

Abstract
Artificial UV radiation is applied in many processes such as UV disinfection, UV curing or biological activation. Besides discharge tubes, LEDs are becoming more important for a rising number of applications in particular UV curing or medical treatment. In general, exposure to UV radiation may cause health problems such as skin aging, eye damage or skin cancer. The potential danger varies with the irradiated wavelengths and the exposure time. The limits and the spectral weighting function of the UV irradiance are given in the directive 2006/25/EC published by the European Comission. The hereby submitted lecture will introduce a radiometer that precisely evaluates the hazard potential while displaying the maximum daily exposition time at a certain measurement point. The digital SiC based UV sensor has a spectral responsivity close to the biological weighting function and is calibrated to different UV LEDs with typical half widths. The sensor can be connected to any Android smartphone.

Johanna Luise Krueger², Dr. Niklas Papathanasiou¹, Stefan Langer¹, Gabriel Hopfenmueller¹, Dr. Tilman Weiss¹
¹sglux GmbH, Berlin, Germany, ²University of Freiberg, Germany

50th Annual Conference of the Radiation Protection Association 2018, Dresden, Germany

Abstract
Environmental data are collected to improve health-related quality of life of citizens. The solar UV-Index provides a good indicator for reasonable sun protection measures and duration of sun light exposure for safety officers and individuals. In Germany the “Bundesamt für Strahlenschutz” manages a solar UV-measurement network to monitor the UV-Index. At ten sites distributed all over Germany spectroradiometers are operated to measure the solar spectrum. The spectroradiometers are expensive and need highly qualified personnel to be operated. Robust and low-maintenance SiC-based UV-Index-radiometers are a viable option to increase the density of this measurement network at low cost. The spectral sensitivity function of such UV-Index-radiometers must reproduce the erythemal action function according to ISO 17166 with high precision.
In this contribution we investigate the effect of production tolerances in the spectral response of SiC-based UV-Index-radiometer (SiC-UVI-radiometer) onto the precision of the measured UV-Index. This is performed by folding a large number of different sun spectra with a variety of spectral responses of actual SiC-UVI-radiometer and the erythemal action curve as defined in the ISO 17166. We can show that the measurement uncertainty of SiC-based UVI-radiometers is ±5 % and therefore in the range of spectroradiometers. We simulated UVI measurements for SiC-based UVI-radiometers with over 2000 different sun spectra and determined a discrepancy-correction-function, which allows a precise UVI-measurement.

Stefan Langer¹, Dr. Niklas Papathanasiou¹, Johanna Luise Krueger², Gabriel Hopfenmueller¹, Dr. Tilman Weiss¹
¹sglux GmbH, Berlin, Germany, ²University of Freiberg, Germany

50th Annual Conference of the Radiation Protection Association 2018, Dresden, Germany
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Abstract
Industrial application of ultraviolet radiation requires not only the evaluation of the effectiveness for the desired process but also an assessment of hazards for the operating personnel. Therefore rules and regulations have been established for the assessment and limitation of health-related threats. A variety of instruments are available on the market for this kind of risk assessment. These devices measure the radiation weighted according to applicable regulatory standards. But the final appraisal of risks such as maximum tolerable exposure time must still be computed manually afterwards.
The new approach presented here is based on a sensor with a spectral response characteristic tailored to a specific regulatory standard. This sensor is connected to a smart-phone. An application on the smart-phone will present the measurement value but also the maximum allowed exposure time in a graphical and acoustical manner. Each radiation source or regulatory guideline requires a specific sensor characteristic for an accurate risk assessment. Therefore the system extensively checks the requirements regarding the suitability of the connected sensor for the selected regulatory norm. These measures reduce the effort and the failure rate and also lower the burden for risk assessment in daily operation.