COLUMN-PROFILE MEASUREMENTS USING FIBER-OPTIC SPECTROSCOPY

Fiber-optic spectroscopy was used to measure the flow of a fluorescent dye in a column packed with glass beads. Optical fibers inserted between the packed beads served as light pipes to transmit excitation light to the measurement zone at their distal end and to return fluorescent emission to a spectrometer. In this way, the dye concentration at the point of measurement was monitored. Data are presented demonstrating that flow can be monitored at several points in the column by multiplexing more than one fiber into a single spectrometer. This technique provides a tool to make fundamental flow measurements that have to date been experimentally impossible.