A Sealed Infrared Absorption Cell of Variable Path Length
Abstract:A new infrared absorption cell of variable path length has been devised. As shown in Figure 1, it is similar in construction to cells of fixed path length but has a sample volume in the shape of a circular wedge. The inner surface of one of the windows has impressed into it a circular inclined plane. The outer edge of this surface is flat so that it can be sealed to the flat surface of the other window. The infrared beam passes through the cell midway between its axis and the outside edge. Thus, the effective sample thickness varies as the cell is rotated about its axis. The rotation is measured by a graduated circular scale. No attempt is made to obtain a quantitative sample thickness because the window surfaces enclosing the sample are not parallel.
Document Type: Research Article
Affiliations: Research and Development Department, American Oil Company, Whiting, Indiana