| 摘要 |
PCT No. PCT/SU80/00096 Sec. 371 Date Jul. 5, 1981 Sec. 102(e) Date May 1, 1981 PCT Filed May 30, 1980 PCT Pub. No. WO81/01334 PCT Pub. Date May 14, 1981.A piezoelectric resonant contact sensor includes an enclosure representing a hollow body of revolution and housing a piezoelectric vibration exciter disposed in a manner providing an acoustic contact. The shape of the exciter is selected to suit the shape of the enclosure. The enclosure accommodates at least two rods with contact lugs which are located so that their axes are perpendicular to the surface of the enclosure. The piezoelectric exciter forms a common oscillatory system in conjunction with the enclosure, the rods and the contact lugs. In the common oscillatory system oscillation frequency of the enclosure with the rods and the contact lugs is equal to the oscillation frequency of a sine-wave electrical signal fed to an exciting electrode of the piezoelectric vibration exciter. |
