A method for operating an ultrasonic fluid meter, preferably an ultrasonic water meter, in a fluid distribution network, includes using an ultrasonic transducer to generate an ultrasonic signal which passes through a measurement path, and determining a flow volume by using evaluation electronics on the basis of a transit time and/or a transit time difference of the ultrasonic signal. A hydraulic force change acting on the ultrasonic transducer through the fluid generates a voltage signal waveform on the ultrasonic transducer and the voltage signal waveform is tapped by the evaluation electronics. An ultrasonic fluid meter, preferably ultrasonic water meter, is also provided.

Pressure measurement apparatus, assemblies and methods are described. According to one aspect, a pressure sensor assembly includes a substrate, a first adhesive member adhered to the substrate, a sensor support adhered to the first adhesive member, a second adhesive member adhered to the sensor support, and a pressure sensor adhered to the second adhesive member and aligned with apertures of the substrate, first adhesive member, and second adhesive member, and the pressure sensor is configured to vary an output signal as a result of changes in pressure of a received air stream, and the output signal is indicative of the changes in pressure of the air stream.

A pressure transducer comprises a housing including a body section and at least one end cap at one end of the body section, which are made of piezoelectric crystal, and a piezoelectric resonator in the housing. The body section and the end cap are bonded by an atomic diffusion bonding method.

A pressure transducer comprises a housing including a body section and at least one end cap at one end of the body section, which are made of piezoelectric crystal, and a piezoelectric resonator in the housing. The body section and the end cap are bonded by an atomic diffusion bonding method.

A pressure detection and display apparatus can provide good visibility even if a person wears polarized sunglasses. The pressure detection and display apparatus includes a piezoelectric sensor having upper electrode, lower electrode, and a piezoelectric layer interposed between the upper electrode and the lower electrode, a polarization plate disposed under the lower electrode, and a display member disposed under the polarization plate. The piezoelectric layer is made of a retardation plate. The piezoelectric sensor and the polarization plate are arranged such that the absorption axis of the piezoelectric layer defines an angle of 20 degrees to 70 degrees relative to the slow phase axis of the polarization plate.

A pressure detection and display apparatus can provide good visibility even if a person wears polarized sunglasses. The pressure detection and display apparatus includes a piezoelectric sensor having upper electrode, lower electrode, and a piezoelectric layer interposed between the upper electrode and the lower electrode, a polarization plate disposed under the lower electrode, and a display member disposed under the polarization plate. The piezoelectric layer is made of a retardation plate. The piezoelectric sensor and the polarization plate are arranged such that the absorption axis of the piezoelectric layer defines an angle of 20 degrees to 70 degrees relative to the slow phase axis of the polarization plate.

A method for forming a pressure sensor includes forming a base of a sapphire material, the base including a cavity formed therein; forming a sapphire membrane on top of the base and over the cavity; forming a lower electrode on top of the membrane; forming a piezoelectric material layer on an upper surface of the lower electrode, the piezoelectric material layer being formed of aluminum nitride (AIN); and forming at least one upper electrode on an upper surface of the piezoelectric material layer.

A method for forming a pressure sensor includes forming a base of a sapphire material, the base including a cavity formed therein; forming a sapphire membrane on top of the base and over the cavity; forming a lower electrode on top of the membrane; forming a piezoelectric material layer on an upper surface of the lower electrode, the piezoelectric material layer being formed of aluminum nitride (AIN); and forming at least one upper electrode on an upper surface of the piezoelectric material layer.

A pressure sensor includes a tubular housing; a diaphragm which is joined to one end portion of the housing through a fusion zone; and a sensor element which is disposed in the housing and to which pressure received by the diaphragm is transmitted. As viewed in a section which contains the center axis of the housing, a pair of the fusion zones exist, and each of the fusion zones is formed in such an inclined manner that its distance from the center axis increases as it extends from the outer surface of the diaphragm toward the other-end-portion side of the housing.

A system is for detecting a location of a touch input on a surface of a propagating medium. The system includes a transmitter coupled to the propagating medium and configured to emit a signal. The signal has been allowed to propagate through the propagating medium and the location of the touch input on the surface of the propagating medium is detected at least in part by detecting an effect of the touch input on the signal that has been allowed to propagate through the propagating medium. The system includes a piezoresistive sensor coupled to the propagating medium. The piezoresistive sensor is configured to at least detect a force, pressure, or applied strain of the touch input on the propagating medium.