© 2024 The Author(s). Published by Elsevier Ltd.González, CarmenVilaplana, Jose ManuelParra Rojas, FranciscoSerrano, Antonio2026-03-202026-03-202024-08-08Measurement 239: 1154660263-2241https://www.sciencedirect.com/science/article/pii/S0263224124013514https://hdl.handle.net/20.500.12666/1798The dataset used for the uncertainty evaluation of Brewer #150 is available at Zenodo [81]. The software (version 2.0) associated with this manuscript for the implementation of the GUM uncertainty framework, Unscented transformation, and Monte Carlo method is published on Zenodo [82]. Ozone data measured by Brewer #150 was used in the creation of this manuscript and can be downloaded from EuBrewNet [83]. Aerosol optical depth measured at INTA/El Arenosillo station was used for the cosine correction and can be downloaded from AERONET [84], [85]. For the calculation of solar UV radiation in the Earth’s atmosphere the libRadtran radiative transfer model was used [71].The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.The uncertainty evaluation of spectral ultraviolet (UV) irradiance measurements is usually performed following the recommendations set by the GUM, the standard for uncertainty evaluation in metrology. In particular, the GUM uncertainty framework (GUF) is applied. Due to the difficulties in the propagation of uncertainties, it is standard practice to neglect the non-linearity of the irradiance model. To verify this assumption, the GUF is validated using the Monte Carlo method (MCM), as recommended by the GUM. As an alternative to these methods, an Unscented transformation (UT) has also been implemented and validated with the MCM. The data used are the UV scans recorded by a Brewer MKIII spectroradiometer at El Arenosillo Observatory. Evaluation of the spectral ratios between the combined standard uncertainties provided by the GUF, the UT, and the MCM showed that the agreement between the three methodologies is satisfactory.engAttribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/Ultraviolet irradianceUncertaintyMonte carloGUMUnscented transformationBrewer spectrometerinfo:eu-repo/semantics/article10.1016/j.measurement.2024.115466http://dx.doi.org/10.13039/501100011033info:eu-repo/semantics/openAccess