IEC 62631-3-1 specifies the general method for measuring the volume resistance and volume resistivity of solid electrical insulating materials using DC voltage methods. The test determines how well a material resists the flow of direct current through its bulk.
The test uses a three-electrode system (guarded electrode configuration) where a DC voltage is applied across a specimen of defined geometry and the resulting current is measured after a specified electrification time. Volume resistivity is calculated from the measured resistance, specimen dimensions, and electrode geometry.
Volume resistivity is a fundamental property of insulating materials used in wire and cable construction, determining the ability of the insulation to prevent leakage current flow between conductors.