| 摘要 |
PROBLEM TO BE SOLVED: To obtain an easy and accurate measuring method for a piezoelectric constant at a low cost by impressing voltage in a layered measuring body and deforming and detecting the displacement of reflection light due to the deformation, with a photoelectric element. SOLUTION: A laser beam generated by a laser source 1 is introduced to the surface of a measuring body 3 fixed with a holding jig 2. The angle of the jig 2 is controlled so that the laser beam reflected on the surface of the measuring body 3 comes in the center of a photoelectric element 5. Then the element 5 is moved for a certain degree with a piezoelectric element 6 and the change in the quantity of light at that moment is measured to be a calibration value. When voltage is impressed in the measuring body with a function generator 4, the measuring body 3 is deformed and resultantly, the quantity of light on the light receiving surface of the element 5 changes. In the next, the distortion of the measuring body is obtained with using a calibration value. By dividing the distortion of the measuring body 3 with the impressed voltage, a piezoelectric constant is obtained. |
