Transducer for detecting pressure changes in pipes

A transducer for detecting pressure changes in a pipe by detecting deformation of the pipe resulting from the inner pressure changes of the pipe and for converting such detected pressure changes into electrical signals, said transducer comprising:

• a piezoelectric element having a bimorph structure, said piezoelectric element having a construction including an intermediate layer interposed between a pair of piezoelectric pieces;
• a holder for pressing said piezoelectric element against an outer surface of a pipe, said holder being sufficiently elastic to allow opposite ends of said piezoelectric element, taken in the circumferential direction of the pipe, to abut elastically against the periphery of the pipe;
• and
• said piezoelectric element to be pressed against the pipe having an inside diameter smaller than the outside diameter of the pipe in the natural and undeformed condition thereof.

A transducer for detecting pressure changes in a pipe by detecting deformation of the pipe resulting from the inner pressure changes of the pipe and for converting such detected pressure changes into electrical signals, said transducer comprising:

• a piezoelectric element having a bimorph structure, said piezoelectric element having a construction including an intermediate layer interposed between a pair of piezoelectric pieces;
• a semi-cylindrical holder for pressing said piezoelectric element against an outer surface of a pipe, said holder being sufficiently elastic to allow opposite ends of said piezoelectric element, taken in the circumferential direction of the pipe, to abut elastically against the periphery of the pipe, said holder having a compression modulus of elasticity of 10.sup.2 to 10.sup.4 kg/cm.sup.2 ;
• and
• a member having an inner surface facing said holder with the pipe to be interposed therebetween, said inner surface having a radius larger than that of the pipe surface.