Evaluation of a Single‐monochromator Diode Array Spectroradiometer for Sunbed UV‐radiation Measurements¶

ABSTRACT The suitability of a new technology single‐monochromator diode array spectroradiometer for UV‐radiation safety measurements, in particular for sunbed measurements, was evaluated. The linearity, cosine response, temperature response, wavelength scale, stray‐light and slit function of the spectroradiometer were determined and their effects on the measurement accuracy evaluated. The main error sources were stray‐light and nonideal cosine response, for which correction methods are presented. Without correction, the stray‐light may reduce the accuracy of the measurement excessively, particularly in the UV‐B range. The expanded uncertainty of the corrected UV measurements is estimated to be 14%, which is confirmed with the comparative measurements carried out with a well‐characterized double‐monochromator spectroradiometer. The measurement accuracy is sufficient for sunbed measurements, provided that all corrections described above have been done and the user of the instrument has a good understanding of the instrument's operating principles and potential error sources. If these requirements are met, the tested spectroradiometer improves and facilitates market surveillance field measurements of sunbeds.