All s::can spectrometer probes operate using the same measuring principle: Spectrometry. The spectrometer probes are the first and only instruments in the world that can measure optical spectra from 190 to 720 nm directly in liquid media. The substances contained in the medium weaken a light beam emitted by a lamp that moves through the liquid. After contact with the medium its intensity is measured by a detector over a range of wavelengths specific to the application. No detailed knowledge of the chemical and physical basics of measuring is required.