A high-pressure attenuated total reflectance cell for collecting infrared spectra of carbon dioxide mixtures

We present the design of a high-pressure cell for collecting infrared spectra of high-density fluids, such as carbon dioxide, that are essentially opaque over the region where infrared active modes absorb energy. While the cell herein described was designed to mount to the SmartOrbit attenuated total reflectance (ATR) module that fits all Thermo Scientific infrared spectrometers, the body of the cell can be machined to fit any manufacturer's ATR unit equipped with a pressure tower. This cell is simple to construct with readily available parts, it will withstand pressures up to 20 MPa (3000 psi) and it is relatively inexpensive.