METHOD FOR MANUFACTURE OF PIEZOELECTRIC CRYSTAL TRANSDUCER OF GAS MOISTURE CONTENT Russian patent published in 1995 - IPC

FIELD: measurement of gas moisture content. SUBSTANCE: applied to electrodes of piezoelectric element at DT-cut with width-to-length ratio of 0.39 is phenolpolyvinylacetate adhesive in form of stripes along lines connecting corners of piezoelectric element with points of maximum deformation. Adhesive is hardened by heat treatment. Then, applied to the entire surface of piezoelectric element is moisture-sensitive coating which contains alternating layers of adhesive and polycaprolactam. Adhesive layers are formed from 25% solution of adhesive in ethyl alcohol and dried in air 2-5 min. The first layer of caprolactam is formed from 6% solution of it in formic acid by its heating at 150 C for one hour. The second layer of caprolactam is made of its 3% solution in formic acid with same heating treatment. EFFECT: higher efficiency. 2 dwg