Measuring 5 × 5 × 1.5 in., the InfraSpec VFA-IR variable filter array spectrometer from Wilks Enterprise Inc. incorporates an ATR sample plate with an elongated, pulsable source mounted close to one end and a linear variable filter attached to a detector array mounted to the other end. The detector array has 64 elements that provide ~12-cm21 resolution in the mid-IR. It has an RS-232 communications port and is available with 2.5- to 4.8-µm and 5.5- to 10.5-µm variable filter ranges. It includes software for running spectra against source emission/crystal transmission or solvent backgrounds, or as deviations from a standard mixture for quality control applications. It is suitable for PAT measurements in pharmaceutical processing and lubricating-oil condition monitoring.