Changes proposed for the IEC 93 standard concerning measurements of the volume and surface resistivites of solid dielectrics

The IEC93 Standard, prepared by the International Electrotechnical Commission in 1980, sets up methods of measurements, determination and calculation of volume and surface resistivities of solid dielectrics. The document contains some editorial mistakes as well as content-related inaccuracies that require revision. Besides corrections of obvious editorial mistakes it is suggested to introduce some content-related improvements. The most important remarks given in the paper are associated with the following problems: 1) shunting of the current meter by the resitance between guarding and guarded electrodes; 2) significant influence of the electrodes made of conducting rubber on volume resistivity measurements results; 3) errors associated with application of simplified expressions tor resistivities calculations (volume resistivity for tubular samples, surface resistivity for samples with circular electrodes); 4) measuring electrode used for cylindrical samples; 5) increase of the effective surface of the measuring electrode (margin width determination and consideration). Finally, proposals of alterations of particular clauses of the standard, supplemented with appropriate justifications, were given in the paper.