Abstract: A sensor apparatus and electrode configuration within the sensor apparatus for measuring electrical characteristics of an aqueous fibrous composition. The electrode configuration includes an elongated ground electrode and at least one segmented electrode to form an array of measurement electrode cells. The electrode configuration further includes an array of reference electrode cells formed by a plurality of reference electrodes built into the array of measurement electrode cells. The measurement electrode cells and reference electrode cells have a different sensitivity to water weight of the aqueous fibrous composition and the same sensitivity to conductivity of the aqueous fibrous composition. The measurement apparatus obtains simultaneous resistive measurements from both measurement and reference cells and determines the ratio of the measurements such that the affects from conductivity is canceled out of the measurement ratio.

Abstract: The Applicant's invention comprises an apparatus and method for determining the amount of one or more components in a pulping liquor. At a first electrode, a varying voltage is supplied in a voltage range including the half-wave potential of each component of a liquor to be measured, and accounting for variations in the half-wave potential caused by changing process parameters. At a second electrode, which is roughly ⅓ to ¼ the size of the first electrode, the derivative of current intensity is monitored near the known half-wave potential for the various liquor components. Using curve-fitting means, the derivative of current intensity and selected other process condition data is used to determine concentrations of the various liquor components.

Abstract: A single gloss sensor which can perform both DIN gloss measurement and DIN high gloss measurement, using the same hardware, and with minimal delay between the two measurements. The gloss sensor functions by directing light beams from a source to two different positions, either concurrently, or sequentially, between a position which measures gloss (75.degree) and a position which measures high gloss (45.degree). The gloss sensor also provides a reference light beam for correction of errors caused by the window glass, such as by dirt buildup.