Abstract: A linear flaw detector for coated surfaces. An incident beam is provided and sensed above and below the theoretical specular angle. Where a flaw occurs, the reflected signal changes in intensity. By sensing above and below the specular angle, the signal corresponding to the flaw is accented in reference to the signals from the background. The signal corresponding to the flaw may then be separated from background noise and an output provided.

Abstract: A meter for measuring the brightness and/or consistency of pulp slurry. An optical probe introduces light energy into the slurry, which energy is transmitted and back-scattered, and reflected orthogonally. Three signals are provided which correspond to the back-scattered, reflected, and transmitted energy. Each of the signals is ratioed against a reference signal which corresponds to the intensity of the energy introduced into the slurry to provide three outputs proportional to the difference between the reference signal and the received signals. The output corresponding to the back-scattered energy is multiplied by the log of the output corresponding to the transmitted energy to produce a measurement of brightness independent of consistency. The output corresponding to the back-scattered energy is divided by the log of the output corresponding to the reflected energy to produce a measurement of consistency which is independent of the pulp brightness.