Near-infrared (NIR) spectroscopy is an analytical technique based on absorption measured between the visible and mid-infrared electromagnetic spectral region. Strong fundamental absorption bands of moieties occur in the mid-IR region and frequently require mulls or dilutions to bring the absorbances within the detector's linear range. The overtone absorptions enable direct measurement without sample preparation because the absorption is relatively weak. Economic fiber-optic cables can be used to measure processes that are located far from the analyzer by inserting probes into processing equipment.