The Use of Tunable Diode Laser (TDL) Spectroscopy for the Measurement of Air Pollutants on Long and Open Measurement Paths
The tunable diode laser (TDL) spectroscopy is a useful tool for the remote measurement of air pollutants like CO2, CO, NO, H2S or even reactive compounds like HF. The advantage of this method is, that a path-averaged concentration measurement is possible with high sensitivity. Moreover in many cases measurements are possible even at areas where the access is difficult. In this paper the technique of this measurement method is described and examples of applications for the measurement of air pollutants are given, e.g. across the crater and the fumaroles of a volcano in Europe.