Page:NIOSH Manual of Analytical Methods - 3800.pdf/31

ORGANIC AND INORGANIC GASES by FTIR Spectrometry: METHOD 3800, Issue 1, dated 15 March 2003 - Page 31 of 47 Five absorbance spectra for TFE are shown in Figure D1. These spectra were recorded over the entire mid-IR wavenumber range, but only that portion of the spectra showing the most intense TFE absorption bands is included in the Figure. Each of the spectra was calculated by mathematically averaging a number of TFE absorbance spectra recorded with the system configuration parameters given in Table D2, and a linear baseline correction was applied to each of these spectra over the range illustrated in Figure D1.

The reference gas samples were generated by diluting with N$2$ the output of a single standard gas cylinder of TFE. The TFE concentration of the standard cylinder was determined (by the gas vendor) according to NIST-traceable gravimetric measurements, and the flow rates of the cylinder gas were measured with a NIST-traceable volumetric device.

Figure D1. Reference Absorbance Spectra of TFE (x-axis truncated) NIOSH Manual of Analytical Methods, Fourth Edition