IRsweep offers cutting edge optical sensing technology based on semiconductor QCL frequency combs in the mid-infrared. Millisecond time resolution combined with large spectral bandwidth and high-resolution offer new possibilities in trace gas sensing and on-line process analysis. These characteristics allow our systems to excel in high-speed measurements of many different molecules even when hidden in a complex background matrix. IRcell: mid-IR multipass absorption cell The cylindrical IRcell multipass cell combines a long optical path in a small detection volume with robust optical alignment. Thanks to the single piece, single material construction, the cell is especially invariant to thermal expansion and resistant to vibrations. The innovative star-shaped beam pattern allows for easy adaption of the optical path length to your application. By slightly changing the beam incidence angle, an optical path length of 131 cm, or 399 cm can be chosen in a sample volume of only 30 ml.