초록 ▼

A pressure transducer comprising a housing and a piezoelectric resonator in the housing, wherein the resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. or having no Curie temperature up to its melting point greater than 1000° C., and the piezoelectric crystal

A pressure transducer comprising a housing and a piezoelectric resonator in the housing, wherein the resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. or having no Curie temperature up to its melting point greater than 1000° C., and the piezoelectric crystal has a piezoelectric constant more than two times greater than that of quartz.

대표청구항 ▼

1. A pressure transducer comprising: a housing and a piezoelectric resonator in the housing, whereinthe resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. or having no Curie temperature up to its melting point greater than 1000° C., andthe piezoelectric cryst

1. A pressure transducer comprising: a housing and a piezoelectric resonator in the housing, whereinthe resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. or having no Curie temperature up to its melting point greater than 1000° C., andthe piezoelectric crystal has a piezoelectric constant more than two times greater than that of quartz,wherein: the housing comprises a cylindrical body section and at least one end cap at one end of the body section; andthe resonator is formed with an internal element extending in a plane parallel to the longitudinal direction of the body section, the internal element being connected to the internal surface of the body section. 2. The pressure transducer according to claim 1, wherein the piezoelectric crystal is LiNbO3 crystal. 3. The pressure transducer according to claim 1, wherein the piezoelectric crystal is langasite crystal. 4. The pressure transducer according to claim 1, wherein the resonator is configured or designed for vibrating in dual modes of fast and slow thickness-shear vibrations. 5. The pressure transducer according to claim 1, wherein the at least one end cap is a pair of end caps at opposite ends of the body section. 6. The pressure transducer according to claim 1, wherein: the housing is axisymmetric; andthe resonator is located in a radial plane within the housing, the resonator comprising a peripheral portion sandwiched between end caps of the housing. 7. The pressure transducer according to claim 1, wherein the resonator is a plano-convex resonator. 8. The pressure transducer according to claim 1, wherein the resonator is a bi-convex resonator. 9. The pressure transducer according to claim 1, wherein the resonator has different radii of curvature along two orthogonal axes thereof. 10. A pressure transducer comprising: a housing and a piezoelectric resonator in the housing, whereinthe resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. or having no Curie temperature up to its melting point greater than 1000° C., andthe piezoelectric crystal has a piezoelectric constant more than two times greater than that of quartz,wherein:the housing is axisymmetric, the housing comprising a cylindrical body section and at least one end cap at one end of the body section; andthe resonator is formed with a discoid element connected to the internal surface of the body section, the resonator having a generally H-shape in cross section. 11. The pressure transducer according to claim 10, wherein the at least one end cap is a pair of end caps at opposite ends of the body section. 12. A tool for pressure measurement comprising: a pressure transducer and at least one oscillator circuit coupled to the pressure transducer, whereinthe pressure transducer comprising: a housing comprising a cylindrical body section and at least one end cap at one end of the body section;a piezoelectric resonator in the housing, whereinthe resonator is made of a piezoelectric crystal having Curie temperature greater than 1000° C. and a piezoelectric constant more than two times greater than that of quartz, andthe resonator is formed with an internal element extending in a plane parallel to the longitudinal direction of the body section, the internal element being connected to the internal surface of the body section. 13. The tool according to claim 12, further comprising a temperature sensor disposed on or near an outer surface of the pressure transducer.