Novel multipass absorption cell for carbon dioxide detection

Abstract

Infrared Spectroscopy has been confirmed as an interesting technique in the process of environmental pollution monitoring. This detection technique is related to the absorption coefficient of each hazardous gaseous compound. When this coefficient is low, as in the case of carbon dioxide, or else, when the gas concentration is small, the transducer has to be designed in order to maximize the interaction between the gaseous compound and the light beam. In addition, the gas cell must be portable, low-size and cost effective. The multipass absorption cell presented in this communication satisfies both requirements, compact physical size and large interaction length. The design is based on a cylindrical cell with a reflective configuration. The dimensions of this cell are carefully adjusted in order to have a completely closed optical path around the contaminant. With this structure, an optical path about 313 cm. could be achieved with a physical size of 20 cm. In this communication, theoretical simulation and preliminary results will be presented to demonstrate the functionality and versatility of the developed gas cell.