Abstract
Considerable electrical disturbance was observed in the measurement of space charge due to the formation of ice crystals in a cold box, when seeding for the ice crystals was made by blocks of dry ice. Because it was considered that electrical disturbance was related to the electrification of the dry ice, laboratory experiments were made to examine the consideration.
As a result, it was confirmed that dry ice was electrified negatively if it is evaporated in dry air, while it was charged positively if frost condenses on its surface in moist air.
