A fluorometer (and fluorimeter) measures the fluorescence or light emitted by different fluorescing objects. Fluorescence occurs when light of specific wavelength hits and excites electrons in a sample, and the electrons in that sample instantly emit or fluoresce light of a different wavelength. All fluorescent objects have its own fingerprint, meaning that it excites and emits predictable types of light. Analytical measurements provided by Fluorescence Spectroscopy Instrumentation are used in multiple applications including chemistry/biochemistry, medicine, pharmaceuticals, food science, environmental studies and nanotechnology. Fluorescence spectroscopy instruments have been used to examine counterfeit banknotes, materials for optoelectronics, and proteins.