Volume Resistivity is the strength of Gap Pad reducing the flow in electric leakage current. A low number (in Ω•m or Ω•cm) refers to superconductor while a high number 1016 refers to an insulator. ASTM D257 is the standard used in testing this parameter. A standard size specimen is placed between two electrodes for sixty seconds, a voltage is applied and the resistance is measured. Surface or volume resistivity is calculated, and apparent value is given (60 seconds electrification time).