In order to effectively tackle these new applications, the handheld FTIR must not only be stable, rugged and offer good performance, but also be equipped with the appropriate sampling interface. To date, virtually all portable or handheld FTIR spectrometers rely on ATR interfaces to handle applications in which the samples to be analyzed are either powders or liquids. These applications are often simple identification applications, typically for either analyzing unknown samples in homeland defense applications or for raw material quality control in pharmaceutical and chemical applications. However, there is a whole range of applications emerging for handheld FTIRs that require different sampling interfaces. For example, large solid objects as diverse as aircraft fuselages, wind turbine blades, and rare art cannot be effectively analyzed by ATR without excising a small sample and that negates the value of nondestructive analysis. For this reason a range of reflectance sampling interfaces have been designed for the Exoscan handheld FTIR that enable the system to tackle more diverse applications:
In a previous paper, the external reflectance, ATR, and grazing angle sampling systems were discussed. A new sampling interface using diffuse reflectance has recently been developed that tackles a broad range of applications.