Cov khoom siv yog raws li kev sib xyaw ua ke nthwv dej ntsuas qhov xav tau ntawm cov khoom siv hluav taws xob tsawg-voltage SPD II, ua kom muaj zog impulse voltage (1.2/50μs) thiab impulse tam sim no (8/20μs), yog siv rau qib III xeem thiab limiting voltage test ntawm SPD thiab cov khoom.