Partner: FORTH
Operator: Georgios Theodoropoulos LAPI/EPFL, CSTACC/FORTH, ([email protected])
The LSE NH₃ Monitor is a cutting-edge instrument designed for real-time ammonia (NH₃) measurement in both ambient air and emission sources. It relies on photoacoustic spectroscopy with a quantum cascade laser (QCL), a technique that offers exceptional sensitivity—capable of detecting concentrations well below one part per billion.
Measurement Principle
The system shines a finely tuned laser at wavelengths absorbed by NH₃ molecules. When the modulated laser light is absorbed, it generates tiny pressure variations inside the measurement cell. These acoustic signals are captured by sensitive microphones, and the resulting signal strength is directly linked to the ammonia concentration. This method ensures precise and highly selective results even in complex atmospheric conditions.
Highlights
- Extreme sensitivity: measures ammonia at sub-ppb levels in minutes
- Broad measurement range: from trace background levels to elevated emissions
- Reliable performance: automated operation with minimal need for maintenance
- Selective detection: little interference from other gases such as CO₂ or H₂O
- Easy integration: outputs compatible with laboratory and field monitoring systems
Applications
This monitor is suitable for a wide range of scientific and environmental uses, including:
- Tracking ammonia in outdoor air for environmental research
- Continuous monitoring of agricultural and industrial emissions
- Studying ammonia’s role in atmospheric chemistry and particle formation
- Supporting regulatory compliance and emission reduction programs