Imaging of gas leaks (especially of methane, but also of other gases) has traditionally been done with portable infrared cameras based on cooled InSb and QWIP FPAs. In these, either the FPA spectral response is tuned to the absorption wavelength of the gas of interest or a spectral filter is used in front of it. Alternatively, high-end spectrally selective (Fourier Transform Infrared – FTIR) cameras (also based on cooled FPAs) are used to detect gas leaks with high sensitivity, but at a price premium.
Now, a new generation of innovative uncooled gas sensors are being developed to not just monitor large gas leaks but also act as monitors for small leaks.