Josef Schreder

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A six-channel moderate-bandwidth filter instrument for measurement of UV and visible radiation has been developed. The characteristic of the instrument are described, including the spectral and the angular responses. Furthermore the calibration procedure is outlined. Combining information from several channels, one may determine the total ozone-column(More)
A transportable reference spectroradiometer for measuring spectral solar ultraviolet irradiance has been developed and validated. The expanded uncertainty of solar irradiance measurements with this reference spectroradiometer, based on the described methodology, is 8.8% to 4.6%, depending on the wavelength and the solar zenith angle. The accuracy of the(More)
To quantify the effect of ambient temperature on the voltage signal of Solar Light UV-Biometers, spectral response functions of two instruments were determined in the laboratory under various external temperature conditions. Despite the biometer's internal temperature stabilization, a temperature increase of 20 degrees C at the outside of an instrument's(More)
BACKGROUND To test the effectiveness of commercially available ultraviolet (UV)-protective eye drops (8-hydroxy-1-methylchinolinium methylsulphate) which are recommended for protection against both solar and artificial UV radiation. METHODS The spectral transmission in the wavelength range from 250 to 500 nm was investigated in 1-nm steps using a(More)
The relative spectral responses of erythemally weighted broadband radiometers determined at three different laboratories are compared, and the systems are described. The results of measurements of four different broadband radiometers are discussed. Although the common dynamic range of the measured relative spectral responses is approximately 10(4), the(More)
A method is presented that combines individual ground based ultraviolet (UV) measurements from the Austrian UVB monitoring network and area-wide data of the distribution of clouds derived from satellite images to generate a UV-Index map all over the region. The Austrian UVB Monitoring network provides near real time ground based 5 measurements of surface UV(More)
PURPOSE To assess the feasibility of image transfer for teleradiologic consultations using the Austrian Academic Computer Network (ACOnet). The ACOnet corresponds between the main universities to a MAN (Metropolitan Area Network) with a transfer rate of 4 Mbps. Its use is free of charge for university institutions. MATERIALS AND METHODS 1740 test image(More)
To study the value of the Austrian Academic Computer Network (ACOnet) for teleradiology, 1740 test image data-sets and 620 image data-sets were exchanged between the departments of diagnostic radiology of the Universities of Innsbruck and Graz using the ACOnet service. Data transmission was reliable and fast with an average transfer capacity of 170 kByte/s(More)
This paper introduces a device that was developed to measure the angular response of UV spectroradiometers in the field. This device is designed to be used at the operating position of spectroradiometers; thus the derived angular response also includes any effects from imperfect leveling of the diffuser and corresponds to the actual operational angular(More)
Aspects of different calibration procedures for erythemally weighing broadband radiometers are presented in this study. These instruments are common in projects dealing with ultraviolet radiation effects on humans. Many erythemally weighing broadband radiometers are still operated using a single calibration factor (cf) that is provided with the instrument.(More)
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