The authors summarize a UV-LED calibration concept that relies upon radiant flux, and emphasize the advantages for developing measurement standards in the increasingly important UV spectral range. The extremely low measurement uncertainties (k=2) of the UV-ACS are comparably low to those in the metrologically unproblematic visible range, thereby offering a reliable resource for radiant flux calibration in the UV-A, UV-B, and UV-C ranges.
