Infrared spectroscopy finds wide use for both qualitative and quantitative analysis. Our organization of IR applications follows that traditionally used by others by dividing the broad range of infrar...Infrared spectroscopy finds wide use for both qualitative and quantitative analysis. Our organization of IR applications follows that traditionally used by others by dividing the broad range of infrared radiation into three distinct units: the near-IR, the mid-IR, and the far-IR. Note that the near in near-IR means that it is nearest to the visible range of light. Of these, the most important in terms of the breadth of applications is the mid-IR.