Time-domain spectroscopy is used very often in infrared spectroscopy (FT-IR) and NMR spectroscopy(FT-NMR). It has several advantages over frequency-domain spectroscopy. In frequency-domain experiments, each wavelength must be measured one at a time. This means scans can take several minutes. A single time-domain experiment takes no longer than a minute. Usually it only takes seconds. This means that many scans may be taken for a given sample, and that the scans can be averaged. So not only is the time-domain experiment faster, but it can also have a better signal to noise ratio.