Basic components of optical analysis instruments

    Optical analysis is based on the interaction between electromagnetic radiation and matter, and optical analysis instruments are tools for detecting this interaction. The basic components of various optical analysis instruments include the following four basic parts: signal generator, detection system, signal processing system, and signal readout system. Modern instruments are also equipped with computer control systems.

　　The signal generator converts a physical or chemical property of the substance being tested into an analytical signal, such as the atomic and molecular absorption spectra produced by atoms and molecules absorbing radiation; the atomic emission spectra produced by the heating and thermal excitation of the substance, etc., are all analytical signals. The radiation light source and absorption cell combination system that generates analytical signals is called a signal generator.

　　The detector detects the generated analytical signal and converts it into an easily detectable signal, usually an electrical signal. There are two general types of radiation detectors: one responds to photons; the other responds to heat. All photon detectors are based on the interaction of electromagnetic radiation with a reactive surface to produce electrons (photoemission) or to cause electrons to transition to a state where they can conduct electricity (photoconduction); thermal detectors are non-quantized heat-sensitive sensors .

　　The signal processing system is used to amplify, smooth, filter, modulate the frequency and amplitude of the signal.

　　The signal reading and writing system processes the signal output and displays the signal.

　　The computer control system processes data and controls the instrument. Advanced instruments can optimize measurement conditions according to predetermined programs.