New applications and insights using an old technique

It has been almost 60 years since the first commercial high-resolution FTIR spectrometer was launched. In gas metrology, such FTIR spectrometers have traditionally been used for a few niche applications, but they have never become a real workhorse. The interest in FTIR has recently revived thanks to new measurement challenges involving multiple reactive gases in applications like CCUS, biogas, and hydrogen quality analysis. However, standard commercial FTIR equipment, such as the gas cell, is typically not fit for purpose for these applications. This paper will discuss some of the necessary modifications to gas cells to exploit the full potential of FTIR as a versatile tool for the selective measurement of reactive gases. Further, common pitfalls in spectral data analysis are discussed. Experimental results on reactive gases in NO2 and CCUS gas standards are presented to show what can be learnt from FTIR measurements. The paper will conclude with an outlook on whether there is a future for FTIR spectrometers with the recent advent of broadband laser spectrometers with similar multicomponent measurement capabilities.