本人看的文獻上說用的是焊接，但會有發(fā)裂（hairline crack），這樣會破壞真空，需要用檢漏裝置探測發(fā)裂（原文：The valve and BNC connectors were welded onto the flanges 6^p>f:5  
and we think it likely that a hairline crack is responsible for the bad performance of the vacuum.）。請問專業(yè)人士如何在不破壞真空的情況下將導(dǎo)線引出。 PHx No)   E"H>