In recent years, sensitive, selective and accurate sensing techniques for ammonia gas
detection have been highly demanded since ammonia is both a commonly utilized gas in …

Many scientific papers have been written concerning gas sensors for different sensor
applications using several sensing principles. This review focuses on sensors and sensor …

Breath analysis, a promising new field of medicine and medical instrumentation, potentially
offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic …

Cavity ring-down (CRD) spectroscopy is a direct absorption technique, which can be
performed with pulsed or continuous light sources and has a significantly higher sensitivity …

The vast majority of gaseous chemical substances exhibit fundamental vibrational
absorption bands in the mid-infrared spectral region (≈ 2–25 µm), and the absorption of …

A new technique of cavity enhanced absorption spectroscopy is described. Molecular
absorption spectra are obtained by recording the transmission maxima of the successive …

Much of the important chemistry of the atmosphere takes place on exceedingly small
concentration scales, with principle components occurring at mixing ratios that vary from the …

A new approach to wavelength-modulation photoacoustic spectroscopy is reported, which
incorporates diode lasers in the near infrared and optical fiber amplifiers to enhance …

We demonstrate a compact, open-path, quantum cascade-laser-based atmospheric
ammonia sensor operating at 9.06 μm for high-sensitivity, high temporal resolution, ground …

Two configurations of a continuous wave quantum cascade distributed feedback laser-
based gas sensor for the detection of NO at a parts per billion (ppb) concentration level …