They then measure the decay over time (called ringdown) of the signal. (sciencedaily.com)
The new instrument, developed by NIST chemists Adam Fleisher and David Long and based on a technology called cavity ringdown spectroscopy (CRDS), promises to dramatically reduce the cost of those measurements. (sciencedaily.com)
Continuous methane, CH4, concentrations were measured in a rural area of the upper Spanish plateau from June 2010 to May 2012 by cavity ringdown spectroscopy technique. (ccacoalition.org)