The Interspec 401-X manufactured by Interspectrum OU is a compact and low-cost FTIR/FTNIR instrument for use inside spectroscopy systems. Depending on the beamsplitter, the module covers the spectral range from 650 nm to 25 µm, with spectral resolution from 16.0 to 0.5 cm−1. The collimated and modulated IR output beam has a diameter of 38 mm. The device measures 160 × 260 × 380 mm, weighs 11 kg and integrates with a variety of systems. It can be easily interfaced to a PC. The data acquisition system is based on a 16-bit A/D converter. Electrical input is 12 V.