The illustration here shows a diagram of a single-beam spectrophotometer that uses a monochromator to select the wavelength. The analyst manually selects the wavelength by adjusting the wavelength dial.
Battery-operated, hand-held single-beam spectrophotometers are available, which are easy to transport into the field. A fixed wavelength single-beam spectrophotometer, such as the one illustrated here, is not practical for recording a spectrum because manually adjusting the wavelength and recalibrating the spectrophotometer is awkward and time-consuming. The accuracy of a single-beam spectrophotometer is limited by the stability of its source and detector over time.
The inset photo is from Adi—the original file is located here—and released under a CC-BY-3.0 copyright via Wikimedia Commons.
