| 摘要 |
PURPOSE:To provide a ZnO element suitable for use in a lightning arrester provided with a gap, by including Bi2O3, and using ZnO whose specific dielectric factor is over 600 and whose restrictive voltage ratios at 1mA/cm<2> and 10muA/cm<2> range 1.4 thru 2.0. CONSTITUTION:It is known that a resistant body chiefly containing ZnO and also including a minor amount of Bi2O3, etc., exhibits an excellent linearity, and the restrictive voltage ratio has generally been flattened between 1mA/cm<2> and 10muA/cm<2> according to any conventional method. Contrary to this common sense, the restrictive voltage ratios at 1mA/cm<2> and 10muA/cm<2> shall be made over 1.4 and below 2.0. The specific dielectric factor of ZnO incl. Bi2O3 shall be kept over 600. This provides easy flowing of current in the minor amperage range, causes flash shortcircuit on the series gap 4 side certainly at the time of cloud-to-ground discharge, and enhances the insulative coordinativeness with an arc horn 1. Also the subsequent stream shutoff characteristic is enhanced due to selecting the V1mA/V10muA to below 2.0. |
