Tunable Diode Lasers find their way to the factory floor

In modern process analytics optical methods and technologies are used to measure a wide variety of parameters that describe the state of an industrial process. Practically all the ways in which light interacts with matter are utilized in the wide spectrum of instruments available today for optical analysis. Non-dispersive infrared (NDIR) and gas filter correlation (GFC) analysers operating in the near and mid-IR wavelengths have for decades been the workhorses for demanding industrial gas analysis. More refined spectroscopic methods such as FTIR (Fourier Transform InfraRed) and Raman spectroscopy provide analysis of multiple components with single measurement. A relatively recent addition to the family of optical IR gas analysers are analysers utilizing the unique properties of tunable diode lasers for gas analysis. This technique is often referred to as Tunable Diode Laser Absorption Spectroscopy (TDLAS), and the analysers are known as TDL gas analysers.