Applied Physics B

, Volume 85, Issue 2, pp 323–328

Ammonia trace measurements at ppb level based on near-IR photoacoustic spectroscopy

Article

DOI: 10.1007/s00340-006-2335-6

Cite this article as:
Besson, JP., Schilt, S., Rochat, E. et al. Appl. Phys. B (2006) 85: 323. doi:10.1007/s00340-006-2335-6

Abstract

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.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • J.-P. Besson
    • 1
  • S. Schilt
    • 1
  • E. Rochat
    • 2
  • L. Thévenaz
    • 1
  1. 1.Nanophotonics and Metrology LaboratoryEcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
  2. 2.Omnisens SAMorgesSwitzerland