ASTM D257 − 14 (Reapproved 2021)´1 ASTM D257-2014体积表面电阻率测试仪

Standard Test Methods for DC Resistance or Conductance of Insulating Materials1 1.1 These test methods cover direct-current procedures for the measurement of dc insulation resistance, volume resistance, and surface resistance. From such measurements and the geometric dimensions of specimen and electrodes, both volume and surface resistivity of electrical insulating materials can be calculated, as well as the corresponding conductances and conductivities. 1.2 These test methods are not suitable f