| abstract |
An on-line, fiber-optic based apparatus for monitoring the concentration of a chemical substance at a plurality of locations in a chemical processing system comprises a plurality of probes, each of which is at a different location in the system, a light source, optic fibers for carrying light to and from the probes, a multiplexer for switching light from the source from one probe to the next in series, a diode array spectrophotometer for producing a spectrum from the light received from the probes, and a computer programmed to analyze the spectra so produced. The probes allow the light to pass through the chemical substance so that a portion of the light is absorbed before being returned to the multiplexer. A standard and a reference cell are included for data validation and error checking. |