PIEZO-PACKAGE NON-DESTRUCTIVE TESTING METHOD Russian patent published in 2020 - IPC H04R29/00 

FIELD: non-destructive testing methods.

SUBSTANCE: invention relates to piezo-package non-destructive testing methods and assessment of quality of their component parts gluing. Proposed method consists in supply of voltage of variable frequency to input of piezo package and measurement of current intensity. Current frequency is varied in the range of the first overtone of piezoelectric cell 2.5ƒ^L_res<ƒ<2.7(ƒ^U_res+Δƒ_max), where Δƒ_max=ƒ_a-ƒ_res – maximum value of antiresonance frequency difference ƒ_a and resonance ƒ_res of piezoelectric elements, ƒ^L_res and ƒ^U_res – lower and upper frequencies of radial resonance, measuring active G_p and reactive B_p components of current to voltage ratio with frequency step of not more than 1 kHz, determining according to AFC active conductivity component bandwidth Δƒ_0.5Gp=ƒ^U_0.5Gp – ƒ^L_0.5Gp, where ƒ^U_0.5Gp and ƒ^L_0.5Gp – upper and lower frequencies, and by AFC of the reactive component of conductivity – a sign of this value and the satisfactory quality of the piezo package is stated by meeting two conditions: inequality Δƒ_0.5Gp≤(ƒ^U_res – ƒ^L_res)/2.6 and presence of change of positive sign of value B_p to negative value.

EFFECT: elimination of difficulties of reliable interpretation of control results.

1 cl, 1 tbl, 5 dwg