Shock polarization and changes in conductivity have been observed in previous electrical investigations of the shock behavior of crystalline materials. For this reason a differential system has been designed by LLNL in their investigations of the conductivity under shock to separate these effects. The measurement removes voltages produced in the shock electrical field allowing determination of those induced by resistance changes. Potassium chloride has been studied extensively and experiments are reported in which it is shocked to various stresses in order to observe electrical effects. The behavior observed when single crystal and pressed targets are shocked above and below the B1:B2 phase transition is presented. The effects of loading to a stress in a single or in multiple steps are discussed. ©2000 American Institute of Physics.