The Office of the Deputy Assistant Secretary of the Army for Defense Exports and Cooperation funded the U.S. Army Combat Capabilities Development Command (DEVCOM) Chemical Biological Center through the International Cooperative Research and Development program to perform work on comparing efficacy of a traditional IR method used as a standard within DEVCOM and by international collaborators with that of an emerging technology, cavity ring down spectroscopy (CRDS). CRDS provides a stronger response per volume than traditional IR for vapor analysis at the same concentration via use of a reflective cavity. Although this technique is normally employed in a very select bandwidth in the IR, commercial products that can interrogate a greater bandwidth have only recently become available. Herein, we directly compare a commercial CRDS unit with a commercial IR instrument and evaluate system response and estimated limits of detection for both instruments for the Gas Distribution Integrity Management program, methyl salicylate, and ethanol. CRDS offers up to two orders of magnitude greater sensitivity than the traditional IR instrumentation. The CRDS and the traditional IR instruments have greater spectral noise in different areas of the spectra. Care should be taken when identifying the peaks to evaluate.