TY - JOUR
AU - Thévenaz, L.
AB - A photoacoustic sensor using a laser diode emitting near 1532 nm in combination with an erbium-doped fibre amplifier has been developed for ammonia trace gas analysis at atmospheric pressure. NH3 concentration measurements down to 6 ppb and a noise-equivalent detection limit below 3 ppb in dry air are demonstrated. Two wavelength-modulation schemes with 1f and 2f detection using a lock-in amplifier were investigated and compared to maximise the signal-to-noise ratio. A quantitative analysis of CO2 and H2O interference with NH3 is presented. Typical concentrations present in ambient air of 400 ppm CO2 and 1.15% H2O (50% relative humidity at 20 °C) result in a NH3 equivalent concentration of 36 ppb and 100 ppb, respectively. 
TI - Ammonia trace measurements at ppb level based on near-IR photoacoustic spectroscopy
JO - Applied Physics B
DO - 10.1007/s00340-006-2335-6
DA - 2006-06-29
UR - https://www.deepdyve.com/lp/springer-journals/ammonia-trace-measurements-at-ppb-level-based-on-near-ir-photoacoustic-EvJf2fKClA
SP - 323
EP - 328
VL - 85
IS - 3
DP - DeepDyve
ER -