Abstract
<jats:p>This article presents the design, construction, and calibration of a portable instrument capable of measuring the solar spectrum in the visible region (430–650 nm), as well a UVA, UVB, and UVC radiation, while also determining the ultraviolet radiation index. The hardware was constructed by integrating a Raspberry Pi 4B, a Raspberry Pi HQ camera coupled to a spectroscope for solar spectrum analysis, and an AS7331 sensor for UV radiation measurement. The control software was developed in Python and includes a graphical user interface that displays the solar spectrum and UVA, UVB, and UVC radiation levels, in addition to calculating the ultraviolet index from UVB-band measurements. The instrument was calibrated using a mercury (Hg) spectral lamp, a reference spectrometer, and commercial UVA and UVB radiation meters. The prototype spectrometer was calibrated and adjusted in the city of Arequipa. During this stage, the equations required to convert the digital signals from the sensors into radiometric units were determined, and the measurement uncertainty of the instrument was obtained. Finally, the instrument was evaluated under field conditions at three locations situated at different altitudes: Camaná (0 m a.s.l.), Arequipa (2330 m a.s.l.), and Sumbay (4100 m a.s.l.). The spectrometer recorded irradiance values of 111.2 W/m2, 670.7 W/m2, and 643.1 W/m2 in Camaná, Arequipa, and Sumbay, respectively, and exhibited a maximum deviation of 15.8 W/m2 from the measurements obtained with the reference instrument. Likewise, maximum differences of 0.27 mW/cm2, 0.02 mW/cm2, and 0.01 mW/cm2 were observed for UVA, UVB, and UVC radiation measurements, respectively. These differences were not significant relative to the order of magnitude of the measurements obtained. In addition, the ultraviolet radiation index was found to reach values of up to 21 in Sumbay, posing a risk to the population of the region. The results showed that the solar spectrum and UV radiation measurements obtained with the constructed instrument were proportional to those recorded by the reference spectrometer and commercial UV meters, demonstrating its reliability and feasibility as a measurement instrument.</jats:p>