CAPILLARY FLUID STREAM CONCENTRATION MEASURING APPARATUS AND METHOD

摘要

There is provided an apparatus for monitoring the relative concentration of an analyte in a fluid stream, with such apparatus including a capillary tube for containing the flowing fluid, optics for directing a single beam of monochromatic light through the capillary tube to produce a diffraction pattern having a number of interference fringes. A translatable photodiode is provided to monitor a portion of one of the fringes passing through a light limiting slit, whereby a signal proportional to the concentration of the analyte in the fluid is produced based upon the varying intensity of the monitored fringe. The capillary tube is preferably provided as a fused silica member having an inner flow diameter of 100 micrometers or less.