A spectrometer separates an incoming light source into its spectral components, while measuring the outgoing light intensity emitted by a substance over a broad spectral range. 📦 For purchasing, use the RP Photonics Buyer's Guide for spectrometers. It provides an expert-curated supplier directory, buyer-focused technical background information, and structured selection criteria to support professional procurement decisions. Spectrometers can analyze gases, liquids, and solids, providing crucial information on their chemical composition, physical properties. The answer is spectroscopy — a chemical analysis method that relies on how different chemical elements interact with light and other types of electromagnetic radiation to determine what the elements are.