Atmospheric Methane Analyzer

Methane is considered the second most important greenhouse gas in the atmosphere. The relatively short lifetime makes it a candidate for mitigating global warming over the near-term. Highly sensitive measurement equipment is required to measure the low atmospheric concentrations with sufficient precision. Comprehensive studies of global warming require this gas to be monitored continuously to unravel its contribution to Earths changing climate. An inexpensive, compact, highly sensitive, in situ monitor for methane is proposed. Efficient and high power diode pumped solid state lasers will be combined with the high-performance trace gas detection sensitivity provided by photoacoustic spectroscopy. A specially tailored device design will allow rugged and inexpensive instrumentation. The proof-of-principle of a new, cost-effective diode-pumped solid state laser based photoacoustic sensor was established in the Phase I project. The system uses inexpensive pump diodes, has a very simple design and shows excellent stability. The laser wavelength could be matched to a methane absorption band. Detection limits in the low single-digit ppb range were achieved for methane. The monitoring of atmospheric methane was demonstrated. An integrated prototype methane sensor will be developed in Phase II. Long term accuracy and precision will be evaluated and the technology will be tested at selected sites. Commercial Applications and Other Benefits: A new sensor platform will be developed that provides ultra-high sensitivity detection for trace gases. Advanced, compact, sensor technologies with high precision at moderate price points are strongly desired in environmental monitoring, modern manufacturing and biomedical diagnostics/monitoring.