35results about "Vacuum gauge using gaseous frictional resistance variation" patented technology

A MEMS pressure sensor for sensing the pressure in a sealed cavity of a MEMS device, comprises a resonant MEMS device having a pressure sensor resonator element which comprises an array of openings. The resonant frequency of the resonant MEMS device is a function of the pressure in the cavity, with resonant frequency increasing with pressure. Over the pressure range 0 to 0.1 kPa, the average change in frequency is at least 10⁻⁶/Pa.

The invention is based on the recognition that for fast oscillation, the elastic force causes the resonance frequency to shift. Therefore, it is possible to sense the pressure by a device with resonance frequency that is sensitive to the pressure.

The invention relates to a device and a method for detecting a fault in a measurement device comprising a resonator and means for measuring a resonant frequency of the resonator. According to the invention, the device further includes means delivering information (S₃) representative of the quality factor of the resonator (3) at the resonant frequency.

A shield arrangement for a vacuum measuring cell has a tubular shield housing encompassing a shield and an exit port for connection to a vacuum measuring cell and a connection opening for the object space to be measured. The shield is between the two openings and is implemented as a screw shield with spiral convolutions, its thread flange in the outer diameter being in contact on the inner wall of the shield housing such that a gas throughflow between the outer diameter of the thread flange and the inner wall is inhibited and is substantially forced into the spiral thread flight, and the exit port is on one side of the tubular section and the connection opening is on the other, opposite side and the screw shield is implemented such that in the axial line of vision the shield arrangement between the two openings is optically tight.

As may be consistent with one or more embodiments discussed herein, an integrated circuit apparatus includes a membrane suspended over a cavity, with the membrane and cavity defining a chamber. The membrane has a plurality of openings therein that pass gas into and out of the chamber. As the membrane is actuated, the volume of the chamber changes to generate a gas pressure inside the chamber that is different than a pressure outside the chamber. A sensor detects a frequency-based characteristic of the membrane responsive to the change in volume, and therein provides an indication of the gas pressure outside the chamber.

A pressure sensor is a micro-electro-mechanical vibrating device, with a silicon substrate (15; 15′) onto which a single-layer or multilayer vibrating assembly (121; 221; 321) is formed. It comprises an electrode (21; 21′), which makes the assembly to oscillate relative to the substrate at the resonance frequency or at another known frequency, and a detector for detecting the actual frequency and/or amplitude of said oscillation. The actual frequency and/or amplitude are affected by the conditions, in particular the pressure, of the external environment and the variations of the frequency and amplitude with respect to the values set by the electrode is used to measure pressure variations in the surrounding environment.

The invention relates to a quartz vacuum sensor with an electrodeless tuning fork and belongs to the quartz vacuum sensor field. The present invention aims to solve the problems of poor stability, poor reliability, poor sensitivity and narrow measuring range of an existing vacuum sensor. A gap is left between two fork arms; arc-shaped grooves are formed at the edge connection positions of each fork arm and a supporting isolation area; two parallel through channels near the top end of each fork arm are formed at the front surface of the corresponding fork arm; 2 to 5 rectangular through groovesare symmetrically formed in the supporting isolation area with the center line of the two fork arms adopted as an axis of symmetry; quartz crystal wafers which are parallel to the two fork arms are arranged at the gap between the two fork arms and around the supporting isolation area and the two fork arms respectively; metal electrodes are bonded onto two side walls of the quartz crystal wafer atthe gap and the inner walls of the quartz crystal wafers around the supporting isolation area and the two fork arms respectively; the metal electrodes and the quartz crystal wafers are of integral structures; and gaps are left between the metal electrodes and the two fork arms. The quartz vacuum sensor is applied to the aviation field and other fields.

In order to provide a vacuum monitor that, even if a sensing mechanism is exposed to an atmosphere into which various types of material gases are introduced, enables the deposition of matter on the sensing mechanism to be prevented, and enables the lifespan of the sensing mechanism to be extended, there are provided a sensing mechanism that is in contact with an atmosphere inside a measurement space, and outputs an output signal that corresponds to a pressure inside this measurement space, and a heater that adjusts a temperature of the sensing mechanism, wherein a set temperature of the heater is adjustable.

The invention relates to the technical field of quartz vacuum sensors, and discloses a surface bending mode double-coupled monolithic high-sensitivity quartz tuning fork vacuum sensor. The vacuum sensor comprises a single-piece type double-open-end multi-fork-arm quartz tuning fork vacuum sensitive resonator of a surface bending mode, a kovar alloy base, a vacuum sensor shell, an envelope-shaped inserting plate type fixing structure, a polytetrafluoroethylene-expanded graphite combined water-repellent sealing gasket, a ceramic fiber waterproof sealing ring and an anti-pollution and mildew-proof filtering cover, wherein the number n of fork arms of the quartz tuning fork vacuum sensitive resonator is larger than or equal to 3; and the dustproof and oil-stain-resistant ceramic filter cap can be self-recovered and self-purified at the temperature of-180 DEG C to + 350 DEG C. The surface bending mode monolithic double-open-end multi-fork-arm quartz tuning fork vacuum sensitive resonator adopts (yxtl)-24 degrees to-50 degrees/5 degrees to 15 degrees cut-type double-rotation-angle quartz crystals, a fundamental wave-surface bending vibration mode is adopted, friction with residual gas in vacuum and mass loading are increased by increasing the arm width and carrying out Hamming weighting on the area of each fork arm electrode, and the surface bending mode of the single-sheet double-open-end multi-fork-arm quartz tuning fork vacuum sensitive resonator is obtained. The variable quantity of dynamic resistance is improved, and the vacuum sensitivity and stability are improved.

An electromechanical pressure sensor includes an electromechanical resonator having a driving electrode, a sensing electrode, and a beam resonator arranged between the driving and sensing electrodes. The beam resonator includes a resonator beam coupled on a first end to a first fixed anchor and coupled on a second end to a fixed second fixed anchor. The electromechanical resonator also includes a first voltage source coupled to the driving electrode and configured to provide an alternating current to the driving electrode and a second voltage source coupled to the first fixed anchor. The second voltage source provides a DC bias to the resonator beam. The electromechanical resonator further includes a third voltage source coupled to the resonator beam via the first and second fixed anchors. The third voltage source is configured to supply a voltage to the resonator beam that results in a temperature differential between the resonator beam and the first and second fixed anchors. The electromechanical resonator also includes a processor coupled to the sensing electrode and configured to correlate a voltage on the sensing electrode with a pressure value.

The invention relates to the technical field of vacuum sensing, and discloses a monolithic surface bending mode double-coupling five-fork-arm quartz tuning fork vacuum sensitive resonator, which is composed of a five-fork-arm surface bending mode quartz tuning fork resonator plate, a quartz vacuum sensitive resonator tube socket and a quartz tuning fork vacuum sensitive resonator anti-pollution moisture-proof filter cap, the five-fork arm surface bending mode quartz tuning fork resonator piece is arranged in a vacuum sensitive resonator packaging part formed by the quartz vacuum sensitive resonator tube socket and the quartz tuning fork vacuum sensitive resonator anti-pollution moisture-proof filter cap; the (yxtl)-24 degrees to-50 degrees/5 degrees to 15 degrees cut quartz crystal is suitable for a single-chip double-open-end five-fork-arm quartz tuning fork vacuum sensitive resonator of a surface bending mode and a single-chip double-group open-end and closed-end five-fork-arm quartz tuning fork vacuum sensitive resonator of the surface bending mode. And the temperature stability of the quartz tuning fork resonator is far better than that of the existing single-closed-end quartz tuning fork resonator and double-closed-end quartz tuning fork resonators.

The invention provides a resonator-based vacuum degree detection method. The resonator-based vacuum degree detection method comprises the following steps: emitting an excitation signal; receiving the excitation signal and generating an output signal under the action of the excitation signal; converting the output signal into a digital signal; controlling and adjusting the excitation signal to enable the excitation signal to resonate with the inherent frequency of the resonator, and processing the digital signal to obtain a vibration amplitude corresponding to the real-time vacuum degree of the resonator; and processing the vibration amplitude into a real-time vacuum degree value and displaying the real-time vacuum degree value. The invention also provides a resonator-based vacuum degree detection system and a resonator-based vacuum degree detection device.

A lithography apparatus is disclosed, which comprises a mirror having at least two mirror segments which are joined together in such a way that an interspace is formed between the mirror segments, and a sensor for detecting the relative position of the mirror segments, wherein the sensor is arranged in the interspace between the mirror segments.

An optomechanical pressure-measurement system measures pressure in the range of 10⁻⁶ Pa-10⁻² Pa by measuring various properties of a vibrational mode of an ultra-thin membrane member. With independent measurements of the thickness and density of the membrane, in addition to the measured vibration mode properties, the system can operate as a primary pressure sensor. The membrane member is mounted on a vibration-isolated mount and is excited by a drive force. A laser beam impinges on the excited membrane, and an optical phase detector detects the amplitude of the oscillations, as well as parameters of the laser beam affected by the membrane vibration. In one embodiment, a mechanical damping is computed based on the amplitude or frequency shift (depending on the pressure range), and the pressure based on the ring-down time of the membrane vibration mode.