Ultraviolet–visible spectroscopy single-beam instrument, the cuvette containing only a solvent has to be measured first. Mettler Toledo developed a single beam array spectrophotometer that allows fast and accurate measurements over the UV/VIS range. The light source consists of a Xenon flash lamp for the ultraviolet (UV) as well as for the visible (VIS) and near-infrared wavelength regions covering a spectral range from 190 up to 1100 nm. The lamp flashes are focused on a glass fiber which drives the beam of light onto a cuvette containing the sample solution. The beam passes through the sample and specific wavelengths are absorbed by the
Ultraviolet (Light My Way) naked eye and ultimately unknowable to the human intellect." Conversely, Steve Stockman, author of "Walk On: The Spiritual Journey Of U2", sees "Ultraviolet" as being about Bono's wife Ali Hewson, and "how when he feels like trash, she makes him clean," but says there is good reason to interpret the song as being just as much about God. The song's title supports this view: indigo and violet rarely appear in song lyrics as frequently as other colours, while ultraviolet represents an unseen wavelength beyond the visible spectrum. As such, the title evokes the image of black light or an invisible