The main reason of fire-resistant oil's volume resistivity exceeding the standard in operation was analyzed

and the effects of increasing resistivity by regeneration of diatomite

iron exchange resin and strong polar adsorbent were compared.Results show that

conductive or polar material produced by deterioration of fire resistant oil causes the overproof resistivity

but replacing partial fire resistant oil in operation can not effectively solve this problem.However

adopting strong polar adsorbent can dramatically increase the resistivity of deteriorated fire resistant oil to the level of that of new oil

but the effect of using diatomite or iron exchange resin is not that obvious.