The heated variable path length cell can be heated to 200ºC and comes complete with a programmable ramp and soak temperature controller with RS-232 serial cable computer interface (0017-5548). The cell back plate is water cooled and the body is insulated as is the vernier scale adjustment on the front of the cell to enable in-situ variation of pathlength while the cell is hot and fixtured in the sample compartment of an FTIR instrument.

The cell consists of a cylindrical stainless steel chamber containing parallel windows. The pathlength may be continuously adjusted from 0.05mm to 5mm and reproduced within 0.001mm (1 micrometer). A vernier scale provided on the cylinder permits the cell pathlength to be read within 0.0005mm (0.5 micrometer). In order for weaker absorption bands of many liquids to appear with the proper intensity, the stronger bands will be totally absorbed and their exact location thus obscured. In these situations, the Variable Pathlength Cell may be precisely adjusted to provide just the right intensity for exact location of both weak and strong bands.