1995 年 44 巻 498 号 p. 288-291
The volume resistivity and electromagnetic shielding properties of “Woodceramics” made of porous carbon material were investigated for the purpose of developing a new shielding material.
The measured values of volume resistivity depended on the burning temperature, and changed from 1010Ω·cm to 10-2Ω·cm with increasing burning temperature.
On the shielding tests with the electromagnetic waves from frequencies of 1000kHz to 1GHz, a good electric shielding effect was observed for those burned above 650°C. When the burning temperature was higher than 700°C, some magnetic shielding effect also appeared. Above 900°C, the shielding effet of more than 40dB on was observed for both of the electric and magnetic shielding in wide frequencies.