| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable individual evaluation of soundness of air-tightness in a plurality of bushings, and enable detection of destruction of the air-tightness in the bushings using a single monitor when put into practical use.SOLUTION: In the feedthrough are formed three individual detection holes 13 that penetrate from a side face of a terminal header base 1 through three bushing insertion holes 11. On both ends in a shaft direction of the bushing insertion holes 11 are sealed bushings 2 having holes for detecting air-tightness states of the bushings 2 provided at the center portions thereof, and the three bushings 2 are individually evaluated for soundness of air-tightness using the three individual detection holes 13 (a). Thereafter, a detection hole 14 is formed to penetrate through from a side face of the terminal header base 1 to the tips of the three individual detection holes 13 and the three individual detection holes 13 are sealed air-tightly with a sealing member 15 so that the detection hole 14 can detect destruction of air-tightness in any one of the bushings 2 (b).</p> |
