Multi-sensor for measuring erythemally weighted irradiance in various directions simultaneously

Estimating the ultraviolet-B (UV-B) solar irradiance and its angular distribution is a matter of interest to both research and commercial institutes. A static multi-sensor instrument is developed in this paper for a simultaneous measuring of the sky and the reflected erythemally weighted UV-B irradiance on multiple inclined surfaces. The instrument employs a pre-developed simple solar irradiance model and a minimum mean square error method to estimate the various irradiance parameters. The multi-sensor instrument comprises a spherical shaped apparatus with the UV-B sensors mounted as follows: seven sky-facing sensors to measure the hemispherical sky irradiance and six sensors facing downwards to measure the reflection from ground. This work aims to devise and outline an elementary, low-cost multi-sensor instrument. The sensor may usefully serve research, commercial, and medical institutes to sample and measure the UV-B irradiance on horizontal as well as on inclined surfaces. The various UV-B calculations for inclined surfaces are aided by the sensor’s integrated software.