Ammonia monitoring at ppb level using photoacoustic spectroscopy for environmental application

Helga Huszár, Andrea Pogány, Zoltán Bozóki, Árpád Mohácsi, László Horváth, Gábor Szabó

Research output: Contribution to journalReview article

52 Citations (Scopus)

Abstract

A novel photoacoustic (PA) trace-ammonia analyzer for measuring ambient ammonia concentration in the lower ppb concentration range has been developed. It is based on a wavelength-modulated, telecommunication type, room temperature-operated diode laser light source, an acoustically optimized, longitudinal resonator type small volume photoacoustic cell and a compact multi-functional electronics unit, which ensures the fully automatic long-term operation of the system. It has a response time below 2 min, which is achieved by using a photoacoustic cell made of polyvinylidene fluoride (PVDF) and gas-handling tubes made of polyamide 11 (PA-11). A dual wavelength measurement method with optimized measurement wavelengths and laser modulation parameters was introduced, which proved to efficiently suppress cross-sensitivity to other atmospheric components, most importantly to water vapor, while improving the sensitivity of the system. The developed PA system was tested with reference to a continuous-flow denuder system (AMANDA) under both laboratory and simulated field conditions, and it featured highly reliable, fully automatic operation with a detection limit of about 50 ppb of ammonia.

Original languageEnglish
Pages (from-to)1027-1033
Number of pages7
JournalSensors and Actuators, B: Chemical
Volume134
Issue number2
DOIs
Publication statusPublished - Sep 25 2008

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Keywords

  • Ammonia
  • Photoacoustic spectroscopy
  • ppb level detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

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