| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a hydrogen sensor of a type capable of satisfying various characteristics required for a sensor for detecting hydrogen (leakage) in a fuel cell as a power source for a vehicle. <P>SOLUTION: In this hydrogen sensor using a ball SAW device (spherical surface acoustic wave-device) as a hydrogen detecting part, a membrane comprising a material of excellent hydrogen selectivity selected from a group consisting of a ceramic-metal composite material, a rare earth metal such as yttrium and a hydride thereof is formed on an annular surface, that is a propagation route of an SAW (surface acoustic wave), and a hydrogen concentration in an environment put with the hydrogen detecting part is evaluated by analyzing the SAW propagated through the device. The spherical surface acoustic wave-devices 10A, 10B in a measuring system A and a calibration system B are used therein, and a difference in an SAW propagation speed is directly detected by measuring a phase difference between fellow circulation reception signals from the elements 10A, 10B. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
