Measuring CO2 and CH4 with a portable gas analyzer: Closed-loop operation, optimization and assessment.

ABSTRACT: The use of cavity ring-down spectrometer (CRDS) based portable greenhouse gas analyzers (PGAs) in closed-loop configuration to measure small sample volumes (< 1 l) for CH4 and CO2 concentrations is increasing and offers certain advantages over conventional measurement methods in terms of speed as well as the ability to measure directly in field locations. This first systematic assessment of the uncertainties, problems and issues associated with achieving reliable and repeatable measurement with this technique presents the adaptation, measurement range, calibration and maintenance, accuracy and issues of efficient operation, for one example instrument. Regular open-loop calibration, a precise loop volume estimate, leak free system, and a high standard of injection practices are necessary fo

SUBMITTER: Wilkinson J 

PROVIDER: S-EPMC5884480 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature