Patent ID: 8393224

Claim:
Stress gauge of the type having an acoustic resonant structure including a piezoelectric transducer ( 10 ) connected to one face of a holder ( 20 ) subjected to the stress, characterised in that the holder ( 20 ) comprises a median neutral fibre ( 30 ) situated at a given depth of the face on which is located the piezoelectric transducer and includes opposite the piezoelectric transducer ( 10 ) a reflecting portion ( 40 ) imbedded in the holder intended to reflect volume acoustic waves generated by the piezoelectric transducer ( 10 ) when it is excited according to a harmonic mode of the structure, said acoustic waves propagating into the holder ( 20 ) and entering into resonance, said reflecting portion ( 40 ) being arranged at a distance from the piezoelectric transducer ( 10 ) such that the integral of the stress on the propagation distance of the volume acoustic waves up to their reflection is different from zero, and at the deepest at the depth of the neutral fibre.