Concave cell design for FTIR measurements

摘要

Wedged and V-shaped cells have advantages on depressing strong absorption bands and keeping the photo windows wide open without absorption block.Alternatively,this work presents a concave cell design,which is constructed by a plano-convex CaF_2 lens in combination with a flat plate.Mathematical equations have been provided for data treatment with Matlab programs.The result indicates that the concave cell has advantages similar to the V-shaped cell.Reflection-absorption measurements of ethanol have been conducted on the cell in mid-IR region for demonstration.The spectrum obtained from the concave cell can easily be interpreted to regenerate its normal spectrum,which is fitting well with the spectrum taken in a conventional thin-layer cell.The concave cell is easier to construct and more convenient to operate,willing to have popular usages.