Deuterium lamps are the preferred source for UV spectroscopy. Stray light is a significant problem in UV spectroscopy. Most sources have blackbody type spectra with low ultraviolet and high visible output. Most detectors have better response in the visible. The result, too often, is that the signal produced by scattered visible light exceeds the real signal in the UV. But with these D2 lamp sources, the intense continuum from the vacuum ultraviolet to 500 nm, and the low visible and infrared output, ensure superior signal to noise for many UV measurements.
