| 摘要 |
PROBLEM TO BE SOLVED: To provide a spherical elastic surface wave sensor constituted so as to eliminate the problem that the sensitivity of a gas sensor is affected by a temperature in a case that the temperature coefficient of the propagation speed of the elastic surface wave of a piezoelectric base material is not zero in a gas sensor to which a ball SAW device is applied (the propagation speed of the elastic surface wave is affected by a temperature) and capable of compensating the effect of a change in temperature with respect to the sensitivity of the sensor. SOLUTION: The spherical elastic surface wave sensor is constituted so as to employ a sensor head equipped with a three-dimensional substrate having a curved surface capable defining a circumferential band in an annular state and characterized in that the average of the propagation speeds of the elastic surface wave along the circumferential band is equal between the equal parts obtained by equally dividing the circumferential band into a plurality parts, a plurality of electroacoustic conversion elements, which are positioned on the circumferential band of the three-dimensional substrate to excite the elastic surface waves so as to multiply rounding the same along the circumferential band and provided so as to leave a plurality of equally divided angles from the center of the arc of the circumferential band and the responsive film at least a part of which is present between the electroacoustic conversion elements of the circumferential band of the three dimensional substrate to react with a change in a circumferential environment. COPYRIGHT: (C)2008,JPO&INPIT
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