New Trend in Instrumentation of NIR Spectroscopy—Miniaturization

The emergence of handheld spectrometers in the past decade marked a significant turning point in the evolution of the practical applications of near-infrared (NIR) spectroscopy. Miniaturized sensors enabled a new and previously unattainable spectrum of applications of NIR spectroscopy. Nonetheless, several issues connected with the use of miniaturized spectrometers have become apparent. In contrast to a matured design of a FT-NIR benchtop spectrometer, the handheld devices are much less uniform and incorporate various novel technologies. These compact technologies result in different performance of miniaturized spectrometers, with narrower spectral regions or lower resolution over which they operate. For this reason, current research focus is on thorough systematic evaluation of the applicability limits and analytical performance of these devices in a variety of applications. This chapter aims to present a comprehensive information on the principles of the technology and application potential of miniaturized NIR spectrometers.