Advanced Quartz-Enhanced Photoacoustic Trace Gas Sensor for Early Fire Detection

A spectroscopic trace gas sensor using a distributed feedback diode laser at λ=1.53 µm and based on quartz enhanced photoacoustic spectroscopy technique is described. The sensor is capable of quasi-simultaneous quantification of trace ammonia, hydrogen cyanide, and acetylene (NH₃, HCN, and C₂H₂, respectively) concentrations at ∼100 ppbv levels with a 4s integration time. The sensor design, responsivity, noise, and cross-talk characteristics are reported.