| 摘要 |
PURPOSE:To enable stable detection of the metallic ion in the atm. air with high sensitivity by providing a passage for penetration of ion on a path for propagating a surface acoustic wave on a piezoelectric base plate. CONSTITUTION:A metallic ion detector is provided with window screen-like electrodes 2 for exciting surface acoustic wave and electrodes 3 for receiving surface acoustic wave on a piezoelectric (LiNbO3) base plate 1. An amplifier 5 is inserted between both electrodes 2 and 3 and a transmitted signal detecting part 6 is provided as well. Since a passage 4 for penetration of ion is provided on the path for propagating the surface acoustic wave on the plate 1, the operation unstability owing to diffusion of metallic ion such as Na ion with the conventional metallic ion detector utilizing an MOS type FET is obviated. The detection of the metallic ion with high sensitivity and good stability is thus made possible. |
