Tunable diode laser absorption spectroscopy for detection of multi-component gas: a review

High-sensitivity solutions for real-time and on-line multi-component gas detection are required in coal mine safety, petrochemical and storage and transportation industries, atmospheric and environmental monitoring, combustion diagnosis, and industrial process monitoring and control. In optical technology, Tunable Diode Laser Absorption Spectroscopy (TDLAS) has been proven to be an advanced technology for detection of multi-component gas, which benefits from the high sensitivity, good selectivity, fast response and anti-disturbance of TDLAS sensors. In detection of multi-component gas, the presence of non-negligible cross-interference, cost and performance requirements become a primary concern in the design of many detection schemes. In this review article, the application of TDLAS technology in multi-component gas detection will be discussed in two categories: (I) Multiple lasers for detection of multi-component gas without cross-interference. (II) A single laser for detection of multi-component gas. This article outlines the advantages and disadvantages of applying various schemes in the two categories when TDLAS is applied to multi-component detection, with the aiming of providing ready-made guidance for multi-component detection under various applications.