In situ pressure bulk conductivity

Figure 4. A cross-sectional view of the in situ pressure bulk conductivity cell.

Two important requirements must be met by a technique designed to provide accurate measurements of the bulk conductivity of paper. First, the contact resistance between the electrode and the paper should be either known or negligible and, secondly, the paper should not be significantly modified by the technique used. The in situ pressure bulk conductivity cell satisfies these requirements, as will be shown in the following sections. 

This article has addressed a number of issues relating to the electrical properties of paper or fibrous structures. It was shown that reliable measurement methods are now available for estimating both the bulk and surface conductivities of paper. In the case of the bulk conductivity, a new in situ pressure conductivity cell was described which significantlyreduces contact resistance. The surface conductivity can be determined by the application of a modified four-point probe method first used on paper by Cronch<15). It was shown that the degree of refining has a small effect on the bulk conductivity of paper. 

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