Precision gas cell for infrared spectrometers and the like.

摘要

A gas cell for measuring the chemical constituents of a gas sample generally includes a central body portion having a hollow interior and first and second end plates sealing off the hollow interior. Each end plate includes an integrally formed concave mirror for reflecting an optical beam back and forth through the interior of the gas cell. Typically, one end plate includes two objective mirrors while the other end plate includes a field mirror optically oriented towards the objective mirrors for reflecting the optical beam therebetween. One of the end plates includes a pair of windows, one of which is used to introduce the optical beam into the gas cell interior and the other through which the optical beam exits after making multiple passes between the mirrors. The absorption spectra of the various chemical constituents within the gas sample can be measured by analyzing the exiting beam in a conventional spectrometer. The central body portion includes a pair of datum surfaces which abut against reference surfaces on the end plates to ensure that the distance between and the orientation of the mirrors remains constant, even when the end plates are removed for servicing or exchanged with other end plates having mirrors with different optical orientations. A gas inlet passageway and a gas outlet passageway communicate with the interior of the gas cell so that sample gas may be introduced into and removed from the cell.