Fourier transform infrared (FTIR) instruments started out as laboratory devices, which would perform well if they were kept in a temperature-controlled, vibration-free laboratory environment. Today, FTIRs are being used to monitor from the sides of stacks, on production floors, and in the hearts of industrial plants, next t large pumps and motors. In addition, it is becoming increasingly important to individual users to be able to adapt a measurement system to totally different modes of operation at different times. For example, one measurement program may require open-path monitoring, while the next may need extractive process monitoring. To address both of the challenging measurement environments and the adaptability issues, Unisearch has developed the IMx, a modular FTIR industrial monitor. This system has features, which allow it to perform well in the most challenging environmental conditions and its modular design allows for rapid reconfiguration by the user. In addition to adding versatility, the modular approach also has the pleasant effect of reducing system cost. In what follows, we describe the Imx system and show examples of both open-path and extractive data gathered with it in harsh industrial environments.