Method and apparatus for on-line spectrophotometric chemical analysis of material in moving process stream

摘要

A spectrophotometric apparatus (10) utilizes a sample cell (14) to perform infrared spectrophotometric analysis on a moving process stream (11) containing, for example, polymer melt. Material to be analyzed flows between two closely spaced-apart crystals (40) in an observation chamber (42). Infrared radiation is transmitted from one side of the material through it to the other side. Crystals (40) are contained within threaded retainers (38) and (39) positioned in a bore. The retainers (38) and (39) can be moved towards and away from each other to vary the absorption rate of the material