Showing papers on "Piezoelectric sensor published in 1976"
32 citations
TL;DR: In this paper, the authors derived a mathematical expression for the piezoelectric constant of a dispersal system in which spherical particles are uniformly dispersed in an isotropic, continuous medium.
Abstract: A mathematical expression is derived for the piezoelectric constant of a disperse system in which piezoelectric, anisotropic, spherical particles are uniformly dispersed in a nonpiezoelectric, isotropic, continuous medium.For the case when the sphere has the face-shear-type piezoelectricity and the system is incompressible, the piezoelectric strain constant d14 for the disperse system is given as where φ is the volume fraction of spheres, d14II the piezoelectric strain constant of the sphere, e the dielectric constant, G the elastic constant, and the superscripts I and II refer to the medium and sphere, respectively.For the case when the sphere is extremely rigid and has length-expansion and thickness-expansion types of piezoelectricity, the piezoelectric strain constants d31, d32, d33 under the approximation φ<<1 are given as where KI is the bulk modulus of the medium and α=4GI/3KI.
25 citations
Patent•
19 Apr 1976
TL;DR: In this article, a dynamic pressure sensor employing piezoelectric ceramic elements in a shear mode is presented, which provides high sensitivity and is particularly insensitive to vibration, case strains and the like.
Abstract: A dynamic pressure sensor employing piezoelectric ceramic elements in a shear mode. The ceramic elements are bolted in a sandwich-like assembly which includes collector plates to a support member; a piezoelectric compensating assembly is also bolted to this support member. The sensor provides high sensitivity and is particularly insensitive to vibration, case strains and the like.
13 citations
Patent•
06 Dec 1976
TL;DR: In this article, the authors proposed a support structure for a piezoelectric acceleration transducer with a bearing point or line between the mass and the support structure in such a position that the directional sensitivity of the transducers may be determined by said position.
Abstract: A piezoelectric acceleration transducer has a piezoelectric element with a plane surface arranged in contact with a mass. The mass and the piezoelectric element are held in fixed relationship to each other by a support structure arranged in such a manner that inertia forces effective on said mass are directed to be effective perpendicularly on the plane surface of the piezoelectric element. A bearing point or line is provided between the mass and the support structure in such a position that the directional sensitivity of the transducer may be determined by said position.
11 citations
TL;DR: In this paper, a sensor based on this microweighing principle was investigated for use in continuous monitoring of dissolved CO2, where a didodecylamine coated crystal and a microporous Teflon filter membrane measured dissolved carbon dioxide in aqueous samples.
Abstract: Piezoelectric crystals undergo a change in vibrational frequency proportional to a change in their mass. A sensor based on this microweighing principle was investigated for use in continuous monitoring of dissolved CO2. The crystal coated with a primary amine was sealed into a compartment covered with a gas permeable membrane. A probe utilizing a didodecylamine coated crystal and a microporous Teflon filter membrane measured dissolved carbon dioxide in aqueous samples. A differential mode of measurement with a reference probe referred to water vapor was used to compensate for water vapor interference.
10 citations