Application of FTIR in the Research on Gas Reference Materials

Gas reference materials are widely used in gas measurement and play an important role in achieving traceability of measurement results to the SI units. The measurement of gas composition is indispensable in the development of gas reference materials. Besides chromatography and mass spectrometry, spectroscopy is also widely used. Fourier Transform infrared spectroscopy (FTIR) is a spectrum measurement technology that can be used for purity analysis of raw gases and accurate measurement of characteristic components and interference components of gas reference materials. This paper introduces the applications of FTIR in the measurement of impurities in several kinds of raw gases, and some applications in the property value measurement and international comparison of gas reference materials. The results show that FTIR is more suitable for the measurement of active components and simultaneous measurement of multiple components. The operation of the measurement process is relatively simple and does not require complex optimization and control of the chromatographic column or chromatographic parameters as in GC or GCMS. FTIR is also suitable for the measurement of stable gases. For example, it can obtain high repeatability and accuracy in the measurement of greenhouse gases. This paper points out that the accurate measurement results are related to the calibration method used, and relatively accurate measurement results can be obtained by using single-point exact-match calibration or two-point calibration, with an alternating measurement sequence “reference-sample-reference”.