Abstract:
A condition monitoring system for a pressure vessel includes at least one vibration monitoring probe coupled to at least one pressure vessel component. The system also includes at least one computing device that includes a memory device configured to store data associated with the at least one vibration monitoring probe. The computing device also includes at least one input channel configured to receive the data associated with the at least one vibration monitoring probe. The computing device further includes a processor coupled to the memory device and the at least one input channel. The processor is programmed to determine a deterioration of the material condition of the at least one pressure vessel component by comparing at least a portion of the data associated with the at least one vibration monitoring probe with predetermined vibration parameters.
Abstract:
An air pressure sensor capable of measuring air pressure highly accurately with a simple configuration is provided. The sensor includes: a sealed case with a sealed space formed therein; a first thin plate member which constitutes at least a part of the wall of the sealed case and deforms to allow the capacity of the sealed space to vary corresponding to changes in the outside air pressure; a first PZT which contacts the first thin plate member to thereby detect the natural frequency thereof; and a second thin plate member which has the same vibration characteristics as those of the first thin plate member and is provided outside the sealed case while contacting it; and a second PZT which has the same temperature characteristics as those of the first PZT and contacts the second thin plate member to thereby detect the natural frequency thereof.
Abstract:
A protected resonating sensor may include at least one resonating sensor unit. Each sensor unit has one or more vibratable members. The protected sensor includes a compliant member that forms part of one or more chambers. A first side of the compliant member may be exposed to a medium in a measurement environment. The sensor unit may be any resonating sensor unit having a resonance frequency that depends on the value of a physical variable in a measurement environment. The protected sensor includes a substantially non-compressible medium disposed within the chamber(s). The substantially non-compressible medium may be a liquid or a gel. When the medium is a liquid, the chamber is sealed. When the medium is a gel, the chamber may be sealed or non-sealed. The medium is in contact the vibratable member(s) and with a second side of the compliant member. The medium may have a low vapor pressure. The protected sensor may also be attached to or included in or formed as part of any suitable device or sensor anchoring device and may also be implanted or inserted into a body or an organism. Methods are described for constructing the protected sensor.
Abstract:
A method and apparatus for non-invasively measuring changes in intracranial pressure (ICP) in a patient's skull which allow trends in such pressure to diagnosed over time. A method performed, or an apparatus made in accordance with the instant invention comprises a generation of a predetermined vibration signal which is applied to a first location on a skull, detecting an output vibration from another location on the skull, storing data characteristic of the two signals, repeating the above-mentioned steps over time, and analyzing the data to diagnose changes in ICP over time.
Abstract:
A method of measuring a pressure of a fluid adjacent a wall of a pipe or vessel. A transducer is attached to the wall of the pipe or vessel. A signal is transmitted by the transducer at a characteristic frequency via a plurality of guided wave modes. The characteristic frequency is a frequency at which the guided wave modes are separated in time from each other when received. The signal is received after the plurality of guided wave modes travel in or through the wall a predetermined number of times. The signal has a signal receipt time after the predetermined number of times. The pressure of the fluid is calculated using the signal receipt time.
Abstract:
A method of protecting a resonating sensor is described. The protected resonating sensor may include at least one passive ultrasonically excitable resonating sensor unit. Each sensor unit has one or more vibratable members having a resonating frequency that varies as a function of a physical variable in a measurement environment. The sensor is protected by forming one or more protective chambers defined between a compliant member and the vibratable member(s). A substantially non-compressible medium is disposed within the protective chamber(s). The compliant member has a first side that may be exposed to a measurement environment and a second side that may be exposed to the substantially non-compressible medium. The substantially non-compressible medium may be a liquid or gel and is in contact with the vibratable member(s). When the medium is a liquid, the chamber is sealed. When the medium is a gel, the chamber may be sealed or non-sealed.
Abstract:
A MEMS and/or NEMS pressure measurement device comprising a deformable membrane suspended on a substrate, one of the faces of the membrane being intended to be subjected to the pressure to be measured, detection means with strain gauges for the deformation of the membrane, said detection means being formed on a substrate and a non-deformable arm, transmitting the deformation in an amplified manner of the membrane to the detection means, the arm being rotatably hinged to the substrate about an axis (Y) substantially parallel to the plane of the membrane and which is integral with the membrane so that it transmits a deformation of the membrane to the detection means in an amplified manner.
Abstract:
A pressure sensor includes: an airtight case equipped with first and second pressure input orifices provided respectively on opposing first and second wall surfaces; a cylindrical first bellows fixed on the first wall surface at one end and equipped with a shaft hole communicating with the first pressure input orifice; a cylindrical second bellows fixed on the second wall surface at one end; equipped with a shaft hole communicating with the second pressure input orifice and arranged in series with the first bellows; a resonator-adhering pedestal arranged and fixed between other ends of the first and second bellows; a lamellar piezoelectric resonator supported by the resonator-adhering pedestal, and an oscillation circuit electrically connected to an electrode pattern of the piezoelectric resonator. The piezoelectric resonator is fixed on the second wall surface at one end and fixed on the resonator-adhering pedestal at the other end; a piezoelectric reinforcement plate is fixed between the second wall surface and the resonator-adhering pedestal at a position across the second bellows from the piezoelectric resonator. An inner wall of the airtight case is joined to the resonator-adhering pedestal by a resilient reinforcement member.