| 摘要 |
A method for measuring the fibre/solid matter and filler concentration in the wet end of a paper machine utilises two optical transducers, one of which operates on infrared light and has a reference channel for temperature compensation, and the other operates on polarised light. The mutually different and nonlinear transducer output signal characteristics are determined experimentally prior to measurement for the fibre/solid matter and filler at issue. The output signals then obtained from the transducers for each measurement are combined on the basis of the transducer output signal characteristics experimentally determined prior to measurement, in order to provide a separate value of the fibre/solid matter concentration and a separate value of the filler concentration. A control system using this method comprises a control equipment (11) and at least two optical transducers (12, 13, 14). The control equipment is adapted to combine the transducer output signals from each measurement on the basis of the transducer output signal characteristics determined experimentally prior to measurement, in such a manner that a separate value of the fibre concentration/solid matter concentration and a separate value of the filler concentration are obtained. The addition of retention agent to the head box (9) of the paper machine is controlled by the control equipment in dependence on the calculated retention values. |
