Progress in reducing size and cost of trace gas analyzers based on tunable diode laser absorption spectroscopy

Abstract

Trace gas analysis by near-infrared Tunable Diode Laser Absorption Spectroscopy (TDLAS) has evolved over the past decade from a laboratory specialty to an accepted, robust, and reliable industrial process monitoring and control technology. Early industrial-quality TDLAS analyzers occupied full instrumentation racks and frequently cost several hundred thousands of dollars to purchase and install. The technology has now been refined to the point where complete TDLAS analyzers are available in lightweight battery-operated packages similar to a smoke detector that cost a few thousand dollars. This paper summarizes the current state-of-the-art in near-IR TDLAS sensors, focusing on miniature low-cost devices, and some of their applications.