Abstract:
A resonator device 10 is disclosed. The resonator device may be used in a transducer or a sensor such as a pressure, force or acceleration sensor. The resonator device comprises a resonator 20 provided on a diaphragm 30. A cap 40 is provided which may be fusion bonded to the diaphragm 30 to enclose the resonator 20 and form a hermetically sealed package 10. The resonator device is excited by applying electromagnetic stimulation, such as infra-red or optical stimulation, which may be from a laser via a fiber 50. The resonator device may be interrogated by applying an electromagnetic signal into the optical cavity formed between the resonator 20 and the inside surface of the cap 40 to derive a frequency change of the resonator. As the resonator device incorporates a hermetically sealed package and is stimulated by electromagnetic radiation, it is robust and able to operate in harsh environments.
Abstract:
A measuring system including a sensor positioned to a belt to measure an oscillation or vibration of the belt based at least in part on a trigger threshold. Also, the measuring system may include a diagnostic tool coupled the sensor to receive a plurality of measurements of the oscillation or vibration of the belt, wherein the diagnostic tool may determine a tension of the belt based at least in part on an average of the plurality of measurements of the oscillation or vibration of the belt.
Abstract:
A strain sensor apparatus for a rotatable shaft including a radiation emitter/receiver, a vibration element attached to the shaft and a radiation-reflective annulus surrounding the shaft and vibration element.
Abstract:
A strain or pressure responsive transducer comprises a pair of elongate beam resonators arranged end to end and provided with a flexible coupling therebetween. The arrangement oscillates e.g. in a double see-saw or butterfly mode. The transducer is disposed on a diaphragm whereby strain may be transmitted to the oscillatory system. The frequency of oscillation is a function of this strain.
Abstract:
An optically driven, electromagnetically oscillating resonant sensor subjected to a stress force wherein the optical driving energy and the optically communicated signal generated in response to the stress force are both communicated a substantial distance along a single optical fiber. A portion of the supply energy drives the oscillatory mechanism and a portion is reflected to a frequency detector by the shuttering action of the resonant element. The device may be configured so as to be electrically driven and optically sensed, optically driven and electrically sensed, or both optically driven and optically sensed for maximum retrofit versatility in past, present, and future process control systems.
Abstract:
A resonator device comprises an elastic beam driven electrostatically at its natural frequency, or an harmonic thereof, by voltage pulses applied to an integral paddle member. The voltage pulses are derived from optical pulses fed via an optical fibre and reflected from the paddle member to a photodiode array. There is thus minimal coupling between the beam and the drive system. A positive feedback loop is provided in which light retroreflected from the paddle member is recaptured by the optical fibre and electronically detected, amplified and fed back in phase with the beam oscillations by modulating the optical pulses.
Abstract:
A process to form a laterally offset photodiode (24) for an optically coupled resonator (10) includes implanting a semiconductor substrate (20) to form the laterally offset photodiode adjacent to the resonator. The resonator masks the implanting underneath the resonator when the semiconductor substrate is implanted. Also disclosed is an optically coupled resonator, a process for fabricating an optically coupled resonator, and a device including an optically coupled resonator having a laterally offset photodiode.
Abstract:
A method of driving and sensing a resonant sensor network wherein at least one resonant sensor is driven by a first light from a first light source at a first frequency, wherein said first light source is modulated by an a.c. source. A second light source at a second frequency is utilized sense the resonant frequency of the at least one resonant sensor. Wherein said at least one resonant sensor modulates said second light source. The modulated light is provided to a photo detector and the first light source is filtered out of said reflected light. The detector a.c. amplifies the filtered reflected light, thereby detecting said resonant frequency of the resonant sensor.