| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric sensor capable of measuring viscosity and density of liquid and pressure and degree of vacuum of gas in a wide measurement range with high sensitivity and high accuracy in real time. <P>SOLUTION: A piezoelectric sensor element 11 is configured so that a piezoelectric vibration chip 12 having side part 20a and 20b located at the outside of three vibration arms 19a to 19c which extend from a base portion 18 is fixed and supported in a cantilever fashion at the base portion in a package 13. A communicating hole 17 is provided in the package 13 so as to introduce a fluid to be measured from the outside and allow it to flow therethrough. The side parts of the piezoelectric vibration chip have flat side faces 26a and 26b which are parallel with side faces of the adjacent vibration arms and define narrow gaps 27a and 27b with predetermined dimensions therebetween. When the vibration arms are bended and vibrated in the outward direction of the side faces, a fluid to be measured generates a constant flow of velocity distribution in the respective gaps between the side parts and the vibration arms. Variations of the viscous resistance which is applied to the vibration arms by the fluid to be measured at this time is detected as variations of CI value of the piezoelectric vibration chip so as to detect variations of objects to be measured such as pressure of the fluid to be measured. <P>COPYRIGHT: (C)2012,JPO&INPIT |
