The present invention uses in situ scatterometry to determine if a defect is present on a wafer. The invention incorporates active materials detrimentally affecting the spinning process and materials which are unstable in the cellulose spinning solution, using separate active material and cellulose streams. The thin-film optical filters are substantially normal to the optical path from an optical signal source. Then, the system retrieves all data files associated with the top data file, stores the data files as display data, generates a relation diagram of the data files, and transmits the relation diagram to a user terminal. A pair of channels extend from the transverse bore proximally along the outer surfaces of the shaft.