Abstract: An example device includes processing circuitry configured to receive, from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air. The processing circuitry is further configured to receive, from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure. The processing circuitry is configured to determine, based on the atmospheric pressure sensor signal, an oxygen partial pressure of the ambient air, determine, based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, the one or more calibration parameters, and calibrate, based on the one or more calibration parameters, the oxygen sensor. The calibrated oxygen sensor may be used to, for example, determine the oxygen content of urine of a patient to monitor renal function of the patient.

Abstract: A photo-acoustic gas sensor using a method for modulating the wavelength of the laser radiation, the modulation being obtained via judicious use of an electric current, called the generation current, which pumps the one or more laser sources, and is configured to cause the one or more laser sources to operate in pulsed mode, and of a current, called the base current, which takes non-zero values between each laser pulse with a lower magnitude than the magnitude of the generation current, the magnitude of base current being modulated so that the one or more laser sources emit, into the cell, light radiation having a wavelength that varies periodically about a central wavelength so as to take, at regular intervals, a value specifically suitable for the excitation of a gas to be detected, whereby an interaction between the light radiation and the gas to be detected contained in the cell induces the generation of acoustic waves at a resonant frequency of the cell.

Abstract: A system for detecting overpressure in an aircraft including a door with a door frame and a door leaf with a first and second door leaf face. The door is mountable in an aircraft where the first door leaf face faces the interior and the second door leaf face faces the surroundings of the aircraft. The door leaf is movably attached to the door frame and selectively movable between an opened position where a door opening defined by the door frame is accessible and a closed position where the door leaf closes off the door opening. The door has a pair of contact faces including a first contact face on the door leaf and a second contact face on the door frame.

Abstract: Techniques for gas analysis using a parallel dipole line (PDL) trap viscometer are provided. In one aspect, a gas analysis system is provided which includes: a PDL trap including: a pair of diametric cylindrical magnets, and a diamagnetic rod levitating above the magnets; and a motion detector for capturing motion of the diamagnetic rod. The motion detector can include a digital video camera positioned facing a top of the PDL trap so as to permit capturing video images of the diamagnetic rod and the system can include a computer for receiving and analyzing video images from the video camera. Methods for measuring gas viscosity and pressure using the PDL trap system are also provided.

Abstract: Particulate matter (PM) sensors and diagnostics performed using the PM sensors are disclosed. The PM sensors and diagnostics may be used in exhaust systems, such as vehicle exhaust systems, to detect soot. In at least one embodiment, an electrostatic particulate matter (PM) sensor is provided including first and second spaced apart electrodes forming a bulk gap therebetween having a bulk distance and a localized gap therebetween having a localized distance less than the bulk distance. A controller may be configured to control a voltage between the electrodes to induce an electrostatic discharge at the localized gap at a lower voltage than at the bulk gap. Various diagnostics may be performed using the disclosed PM sensors, including a wiring/continuity diagnostic, a soot detection plausibility diagnostic, and/or an installation diagnostic.

Abstract: A method of making an air data probe may comprise forming a probe body, forming an interior cavity into the probe body, applying a protective shell to the probe body by an additive manufacturing technique, inserting a heating element into the interior cavity, machining a final profile of the air data probe, and forming a sensing port comprising a port passage defined through the probe body and lined by a portion of the protective shell.

Abstract: An air data probe is disclosed. The air data probe may include a probe body having an interior cavity and coated by a protective shell. A sensing port may be disposed in the air data probe and may extend through the probe body. The sensing port may also be lined by the protective shell. The protective shell may be made of an austenitic nickel-chromium alloy, or stainless steel, or any relatively corrosion resistant material. The probe body may be made of nickel, or a nickel alloy, or any relatively thermally conductive material. The protective shell may be joined to the probe body by additive manufacturing, such as laser cladding. In this manner, an air data probe capable withstanding high temperatures without corrosion and yet also being relatively thermally conductive is disclosed.

Abstract: A method and an apparatus for determining the permeation rate of barrier materials, with which in a measuring chamber (8.7) which has at least two shut-off elements (81; 8.2) for opening and closing, a concentration of at least one permeate is determined which, present as a test gas with a constant concentration in a test gas chamber (8.3), is permeated into the measuring chamber (8.7) through a barrier element (8.5) which is arranged between the test gas chamber (8.3) and the measuring chamber (8.7) and which has a known permeable surface (A).

Abstract: Disclosed is a device and method for measuring pressure inside a deformable vessel containing a compressible gas, by the transfer of pressure inside the vessel to a primarily rigid chamber external to the vessel through a flexible membrane covering a window in the chamber, which is filled with a suitable incompressible fluid. The pressure transfer is effectuated by either pressing the vessel against the chamber or the reverse. The transferred pressure is then measured by a traditional gauge or other available pressure sensor. Depending on the elasticity of the vessel exterior wall, a fixed area for compressing a flat area of the vessel exterior wall and transfer membrane is chosen. At this chosen amount of deformation, the pressure differential between the vessel interior and the exterior chamber is zero, facilitating the external measurement of the vessel internal gas pressure.

Abstract: A method and a device for the analysis of gas components of a matrix employ two sensors, which each comprise a cavity enclosed by a membrane. Both membranes, each on one side of the matrix and on the other side, are exposed to a purge gas and subsequently, the timeline of the differential pressure ?ps starting at a start time tA is measured, which is created between the sensors as a consequence of permeation of gas components of the matrix and/or the purge gas through both membranes. From the timeline, a point of time tE is determined, at which the measured differential pressure equals the differential pressure at the point of time tA, whereby the gas component of the matrix, which is different from the purge gas, and its genesis is determined from the time difference ?t=tE?tA.

Abstract: In the specification and drawings, an apparatus for conducting hot work is described and shown with an enclosure; a hot work apparatus operable within the enclosure; and a detector located exterior of the enclosure, the detector being in detecting communication with the interior of the enclosure, such that the detector detects the presence of a condition within the enclosure. A method of conducting hot work is also described and shown.

Abstract: A gas analyzer system to determine the concentration of gases in an automotive air conditioning system comprising: an infrared multi-detector device equipped with a gas analysis chamber; an emitter source emitting infrared radiation in the analysis chamber; infrared multi-detectors generating an electrical measurement quantity based on the absorption of radiation by the gas; a suction pump creating a depression inside the analysis chamber; and an electronic control unit determining a main automotive refrigerant gas concentration and the contaminant gases concentration, based on electrical measurement quantities provided by the multi-detectors and a reference electrical quantity. The control unit controls the pump to suck the gases in the analysis chamber until a condition of absence of gases is achieved, wherein the internal pressure of the chamber reaches a minimum pressure, and then determines the reference electrical quantity, based on the electrical quantity generated in the condition of absence of gases.

Abstract: The present invention relates to a vehicle impact sensor device adapted to detect an impact between a vehicle (1) and a person. The sensor device (6) comprises a tubular enclosure (7) which encloses a gas-filled space (8). The tubular enclosure (7) has a first end (7a) and a second end (7b) and is arranged to extend along a bumper cover (5), when mounted to a vehicle (1). The sensor device (6) further comprises a pressure sensor (9, 9?, 11, 11?) arranged to detect pressure characteristics in the the tubular enclosure (7). The sensor device (6) also comprises a gas pulse device (11, 11?) which is connected to the tubular enclosure (7), the gas pulse device (11, 11?) being arranged to insert gas into, or withdraw gas from, the tubular enclosure (7).

Abstract: Provided are an apparatus for collecting gas samples in a foam and an analysis method using the same, and more particularly, to an apparatus for collecting gas samples in a foam in which the foam is grinded, such that the gas sample in the foam may be effectively collected, and pressure before and after collection of the gas samples may be measured to thereby increase accuracy of gas analysis, such that characteristics of the foam may be more accurately evaluated, and an analysis method using the same.

Abstract: Provided are gas treatment devices and medical equipment thereof. The gas treatment device can include at least a first gas monitoring module and a second gas monitoring module, a master control module and an integrated gas circuit board. A gas outlet, at least one gas inlet and a monitoring interface can be arranged on a surface of the integrated gas circuit board, while a first and a second gas circuits may be arranged inside the integrated gas circuit board. The gas inlet can include a first gas inlet and a second gas inlet. The gas outlet and the first gas inlet can communicate with first and second ends of the first gas circuit, and the second gas inlet can communicate with one end of the second gas circuit. The first and the second gas circuits can communicate with the first and the second gas monitoring modules through corresponding monitoring interfaces.

Abstract: A sensor system is provided for pressure vessels. In one embodiment, a compressor directs compressed air into a purification chamber for removing carbon monoxide from the air. A sensor system housing is fastened to an opening on the purification chamber. The sensor housing provides an electrochemical sensor driven by an independent power supply and an electronic processor for receiving a signal from the electrochemical sensor. If the carbon monoxide in the purification chamber reaches a predetermined level, the electronic processor is programmed to initiate a shutdown of the compressor utilizing a relay cable.

Abstract: A tamper detector is provided for safeguarding a radiological source that is moved into and out of a storage location through an access porthole for storage and use. The radiological source is presumed to have an associated shipping container approved by the U.S. Nuclear Regulatory Commission for transporting the radiological source. The tamper detector typically includes a network of sealed tubing that spans at least a portion of the access porthole. There is an opening in the network of sealed tubing that is large enough for passage therethrough of the radiological source and small enough to prevent passage therethrough of the associated shipping cask. Generally a gas source connector is provided for establishing a gas pressure in the network of sealed tubing, and a pressure drop sensor is provided for detecting a drop in the gas pressure below a preset value.

Abstract: The invention provides a sensor assembly for determining the concentration of hydrogen in an insulating fluid in electric power generation, transmission, and distribution equipment. The assembly includes a housing having an opening therein communicating with the fluid, a hydrogen sensor disposed in the housing and responsive to the concentration of hydrogen in the fluid and generating a signal related to the concentration of hydrogen, and a pressure sensor disposed in the housing responsive to the fluid and generating a second signal indicative of the pressure of the fluid in the equipment. The assembly further includes a signal processor disposed in the housing and connected to the hydrogen sensor and the pressure sensor and responsive to the first and second signals for generating a third signal representing the concentration of hydrogen in the fluid.

Abstract: A method and apparatus for physical vapor deposition are provided herein. In some embodiments, an apparatus for measuring pressure of a substrate processing chamber may include a shield having an annular one-piece body having an inner volume, a top opening and a bottom opening, wherein a bottom of the annular one-piece body includes an inner upwardly extending u-shaped portion, a gas injection adapter disposed about an outer wall of the shield, a pressure measuring conduit formed within the gas injection adapter, wherein the pressure measuring conduit is fluidly coupled the inner volume via a gap formed between an outer wall of the shield and substrate processing chamber components disposed proximate the shield, and wherein the gap has substantially the same pressure as the inner volume, and a pressure detector coupled to the pressure measuring conduit.

Abstract: Methods and systems and are presented for estimating the amount of natural gas provided to a vehicle at a natural gas time-fill filling station. The methods comprise measuring and wirelessly transmitting pre- and post-fill pressures measurements of compressed natural gas in a compressed natural gas storage tank on-board a natural gas vehicle.

Abstract: In the case of a device for detecting physical state variables of a medium, such as pressure or temperature, for example, of a liquid, comprising at least one measuring sensor, which is connected to at least one electrical conductor so as to transmit signals, wherein at least one section of the conductor, which encompasses the sensor, is embedded in a casting compound, the casting compound is embodied, according to the invention, from at least one casting core and a casting jacket, which encloses the casting core, and provision is made in the casting compound for at least one recess for a media-conducting access to a contact surface of the sensor.

Abstract: An apparatus for testing of multiple material samples includes a gas delivery control system operatively connectable to the multiple material samples and configured to provide gas to the multiple material samples. Both a gas composition measurement device and pressure measurement devices are included in the apparatus. The apparatus includes multiple selectively openable and closable valves and a series of conduits configured to selectively connect the multiple material samples individually to the gas composition device and the pressure measurement devices by operation of the valves. A mixing system is selectively connectable to the series of conduits and is operable to cause forced mixing of the gas within the series of conduits to achieve a predetermined uniformity of gas composition within the series of conduits and passages.

Abstract: An apparatus for generating a signal representing one of the density and the pressure of gas within a high voltage circuit breaker based on a dial position of a pressure switch includes a clip configured to mechanically couple to the dial, the clip including a magnet, and lens assembled into the switch between the switch housing and an outer component of the switch. The lens includes a sensor positioned within a cavity of the lens in alignment with the clip magnet to detect the position of the pressure switch dial from a magnetic orientation of the magnet, and circuitry for converting the detected position into an electric signal.

Abstract: A hydrogen sensor includes a housing, which is closed off by a membrane that is made of palladium and selectively only pervious to hydrogen. The housing is evacuated and contains a Pirani pressure sensor. The membrane and the Pirani pressure sensor are each attached to a carrier. Both carriers are joined directly next to one another or kept at a distance by a connection piece. The hydrogen sensor has a high sensitivity and a low response time due to the relatively large membrane surface and the low housing volume. It can be produced in a small size and integrated in the handle of a sniffer-type leak indicator.

Abstract: Process for monitoring the polymerization of ethylene or ethylene and comonomers in the presence of free-radical polymerization initiator at pressures in the range of from 160 MPa to 350 MPa and temperatures in the range of from 100° C. to 350° C.

Abstract: A cover, sample tray and base may form a hydrogen storage engineering properties analyzer. In at least one embodiment, the sample tray includes a plurality of cooling fins, each of which includes a sample well therein. A variety of hydrogen storage materials may be loaded into and unloaded from each sample well by way of a respective sample well opening. The combined cover and sample tray define at least one plenum which may be in fluid communication between a source of pressurized hydrogen gas and each sample well. The cooling fins may be received by a cooling chamber defined within the base and configured to receive a through-flow of heat-exchange fluid. Certain embodiments may include one or more pressure transducers in fluid communication between the plenum and hydrogen source, and thermal transducers connected to portions of the cooling fins.

Abstract: An apparatus for testing of multiple material samples includes a gas delivery control system operatively connectable to the multiple material samples and configured to provide gas to the multiple material samples. Both a gas composition measurement device and pressure measurement devices are included in the apparatus. The apparatus includes multiple selectively openable and closable valves and a series of conduits configured to selectively connect the multiple material samples individually to the gas composition device and the pressure measurement devices by operation of the valves. A mixing system is selectively connectable to the series of conduits and is operable to cause forced mixing of the gas within the series of conduits to achieve a predetermined uniformity of gas composition within the series of conduits and passages.

Abstract: An apparatus and method is provided for determining the static gas pressure in a gas/liquid flow. The apparatus and method may be non-invasive relative to the flow to be analyzed. The apparatus and method may include swirling a multiphase flow so that the flow is separated into a gas core and a liquid outer layer, measuring flow parameters, including the liquid layer tangential velocity, the liquid holdup, and the static pressure of the flow at the wall of conduit, and determining the static gas pressure in the gas core from the measured flow parameters.

Abstract: The object of the invention is a gas-liquid contacting column comprising a gas supply line (2), a liquid supply line (4), at least one functional zone (6) comprising at least one gas-liquid contacting element, functional zone (6) being arranged between gas supply line (2) and liquid supply line (4). Gas supply line (2) cooperates with a distribution zone (8) arranged between the gas supply line and the functional zone, distribution zone (8) consisting of a packing whose height is so selected that the gas coming from the distribution zone circulates with a local velocity over the bed inlet section of the functional zone ranging between ?50% and +50% of the average velocity of the gas circulating in the column.

Abstract: Systems and methods to determine ozone concentration in a gas mixture of ozone and oxygen, based on measurements of a total mass flow and a corresponding change in a chamber pressure accepting the mixture flow, can enable the measurements of ozone concentration at low pressure settings. The ozone concentration determination can be applied to a vacuum processing chamber, enabling precision semiconductor processing.

Abstract: Gas pressure in a cavity is detected with a rod-shaped casing that attaches to an hole that opens into the cavity. A porous filter whose top end face matches with a mold cavity face at a top end of the rod-shaped casing separates gas from melt. Cavity gas from an introduction chamber introduces gas through the porous filter, and a gas pressure sensor detects pressure in the chamber. Melt pressure in the cavity is detected with a pressure transmission rod inserted into the rod-shaped casing whose top end face matches with the mold cavity face, and a pressure sensor fixed and held facing a rear end of the pressure transmission rod detects the cavity melt pressure. Cavity melt temperature is detected with a temperature sensor attached to a thin hole formed at the pressure transmission rod's center and includes a thermocouple at a top end part side of the hole.

Abstract: A method for determining a characteristic such as partial pressure or percentage of a gaseous constituent in a first gas mixture flow (32) in a flow chamber (30) where flows alternatively said first gas mixture flow (32) and a second gas mixture flow (34) comprising the following steps: a) introducing the first gas mixture flow (32) into a sensing chamber (40) when the first gas mixture flow (32) flows in the flow chamber (30), b) preventing introduction of gas from the flow chamber (30) into the sensing chamber (40) at least when the second gas mixture flow (34) flows in the flow chamber (30), c) sensing said characteristic of the first gas mixture flow (32) in the sensing chamber (40).

Abstract: A tamper detector is provided for safeguarding a radiological source that is moved into and out of a storage location through an access porthole for storage and use. The radiological source is presumed to have an associated shipping container approved by the U.S. Nuclear Regulatory Commission for transporting the radiological source. The tamper detector typically includes a network of sealed tubing that spans at least a portion of the access porthole. There is an opening in the network of sealed tubing that is large enough for passage therethrough of the radiological source and small enough to prevent passage therethrough of the associated shipping cask. Generally a gas source connector is provided for establishing a gas pressure in the network of sealed tubing, and a pressure drop sensor is provided for detecting a drop in the gas pressure below a preset value.

Abstract: A gas detector with a selectively adsorbing surface (3) and an acoustic measuring cell (5) is presented. The detector is characterized in that the selectively adsorbing surface (3) and the acoustic measuring cell (5) can be arranged with respect to one another such that gases desorbed by means of thermal desorption from the adsorbing surface (3) reach the acoustic measuring cell (5) and there trigger a pressure wave that can be measured by one or more acoustic pick-ups (13, 14), in particular microphones, which are arranged in the acoustic measuring cell (5). Furthermore, a corresponding method is provided. The detector is particularly suitable for measuring contaminants in interior spaces and ventilation systems.

Abstract: The invention provides a sensor assembly for determining the concentration of hydrogen in an insulating fluid in electric power generation, transmission, and distribution equipment. The assembly includes a housing having an opening therein communicating with the fluid, a hydrogen sensor disposed in the housing and responsive to the concentration of hydrogen in the fluid and generating a signal related to the concentration of hydrogen, and a pressure sensor disposed in the housing responsive to the fluid and generating a second signal indicative of the pressure of the fluid in the equipment. The assembly further includes a signal processor disposed in the housing and connected to the hydrogen sensor and the pressure sensor and responsive to the first and second signals for generating a third signal representing the concentration of hydrogen in the fluid.

Abstract: A gas analyzer for a vacuum chamber includes processing electronics configured to receive mass spectral data, receive input of total pressure in the vacuum chamber, receive external input from at least one sensor, and employ the mass spectral data, the total pressure in the vacuum chamber, and the external input from the at least one sensor to calculate a vacuum quality index based on at least one criteria of quality.

Abstract: The present invention relates to a system for measuring an absolute quantity of each component of a gas using a QMS, more particularly to a system for measuring an absolute quantity of each component of a gas using a QMS, which is capable of performing not only a qualitative analysis but also a quantitative analysis in an accurate manner, using just a trace amount of gas introduced through a pinhole. According to the present invention, the productivity of products can be improved, and production management can be performed in an efficient manner, thereby improving industrial competitiveness.

Abstract: A hydrogen sensor includes a housing, which is closed off by a membrane that is made of palladium and selectively only pervious to hydrogen. The housing is evacuated and contains a Pirani pressure sensor. The membrane and the Pirani pressure sensor are each attached to a carrier. Both carriers are joined directly next to one another or kept at a distance by a connection piece. The hydrogen sensor has a high sensitivity and a low response time due to the relatively large membrane surface and the low housing volume. It can be produced in a small size and integrated in the handle of a sniffer-type leak indicator.

Abstract: The present invention relates to a high-pressure quartz crystal microbalance sensor that is capable of measuring adsorption and diffusion characteristics of nanoporous materials and thin films at high pressures.

Abstract: A method to measure the concentration of a constituent element in a gas sample contained in an analyzer. A sample cell of a detector has an inlet and an outlet. The outlet of the sample cell is sealed. A predetermined mass of a gas sample is received through the inlet into the sample cell over a predetermined pressurization period until substantially the entire mass of the gas sample contained in the analyzer is contained within the sample cell. The gas sample is pressurized to a predetermined pressure over the pressurization period. A concentration of a constituent element in the pressurized gas sample is determined.

Abstract: A method for sensing gas composition and gas pressure, based on the thermal constants of a variable electrical resistor, is presented. The method for sensing gas composition and pressure includes monitoring a variable electrical resistor whose dynamic thermal response is determined by the thermal conductivity and thermal capacity of the surrounding gas of a given atmospheric environment. In the thermal domain, the sensor has a low-pass characteristic, whose phase delay is determined by the thermodynamic characteristics of the surrounding gas such as composition and pressure. The method can be used for sensing gas composition and can also be used for sensing gas pressure.

Abstract: Provided are an apparatus for collecting gas samples in a foam and an analysis method using the same, and more particularly, to an apparatus for collecting gas samples in a foam in which the foam is grinded, such that the gas sample in the foam may be effectively collected, and pressure before and after collection of the gas samples may be measured to thereby increase accuracy of gas analysis, such that characteristics of the foam may be more accurately evaluated, and an analysis method using the same.

Abstract: A monitoring system for monitoring fluid in a fluid supply vessel during operation including dispensing of fluid from the fluid supply vessel. The monitoring system includes (i) one or more sensors for monitoring a characteristic of the fluid supply vessel or the fluid dispensed therefrom, (ii) a data acquisition module operatively coupled to the one or more sensors to receive monitoring data therefrom and responsively generate an output correlative to the characteristic monitored by the one or more sensors, and (iii) a processor and display operatively coupled with the data acquisition module and arranged to process the output from the data acquisition module and responsively output a graphical representation of fluid in the fluid supply vessel.

Abstract: A method for detecting the presence or absence of a gas bubble in an aqueous liquid is provided comprising providing a sensor positioned within a measuring chamber, wherein the sensor is configured to determine the concentration of a gaseous component dissolved in a liquid, the sensor comprising a sensitive region; setting a gas partial pressure at the sensor, wherein the gas partial pressure differs from an expected value of the gas partial pressure of the gaseous component of a liquid to be measured; exposing the sensor to the liquid to be measured; resting the liquid until standstill is attained; recording a signal from the sensor as a function of time until the signal becomes constant; and detecting the presence or absence of a gas bubble from the variation of the signal over time. The gas bubble, if present, is in at least partial contact with the sensitive region of the sensor.

Abstract: An apparatus for notifying a user which gas tank(s) to connect to an enclosed chamber such as an incubator. The user inputs the desired setpoints for gasses such as O2 and CO2, and the corresponding gas level is determined. The determined gas level is compared with the setpoint of the gas and can display, which gas tank(s) should be hooked up to chamber.

Abstract: A gas gauge (100) is provided for use in a vacuum environment having a measurement gas flow channel (105). The gas gauge comprises a measurement nozzle (110) in the measurement gas flow channel (105). The measurement nozzle (110) is configured to operate at a sonically choked flow condition of a volumetric flow being sourced from a gas supply (120) coupled to the measurement gas flow channel (105). The gas gauge (100) further comprises a pressure sensor (127) operatively coupled to the measurement gas flow channel (105) downstream from the sonically choked flow condition of the volumetric flow to measure a differential pressure of the volumetric flow for providing an indication of a gap (130) between a distal end of the measurement nozzle (135) and a target surface (140) proximal thereto.

Abstract: Methods of determining an amount of precursor in an ampoule have been provided herein. In some embodiments, a method for determining an amount of solid precursor in an ampoule may include determining a first pressure in an ampoule having a first volume partially filled with a solid precursor; flowing an amount of a first gas into the ampoule to establish a second pressure in the ampoule; determining a remaining portion of the first volume based on a relationship between the first pressure, the second pressure, and the amount of the first gas flowed into the ampoule; and determining the amount of solid precursor in the ampoule based on the first volume and the remaining portion of the first volume.

Abstract: A pressure sensor is arranged on a supply/discharge pipe of a reactive gas to be supplied to or discharged from a fuel cell, and measures the pressure of the reactive gas in the pipe. The pressure sensor is provided with an engaging section which has a screw and engages with a pipe wall of the pipe; a pressure detecting section, which faces a reactive gas channel of the pipe and detects the pressure inside the pipe by displacement; a displacement sensor, which is arranged in the pressure detecting sensor and measures displacement of the pressure detecting section; and a buffer section, which connects the engaging section with the pressure detecting section by sandwiching a buffer layer which communicates with the reactive gas channel of the pipe, and eliminates abnormal displacement of the pressure detecting section by deforming to a stress generated by torque of the screw, at the time when the pressure sensor is engaged with the pipe.

Abstract: A selective gas sensor is for determining the presence of a test gas, for example, helium includes an evacuated housing, sealed by a selectively gas-permeable membrane. The membrane is part of a sight glass, whereby the glass pane is provided with a hole, sealed by the membrane made from a silicon material. The frame of the membrane wall is connected to the housing by means of a high-vacuum soft-metal seal. The housing can also form one of the electrodes of the gas pressure sensor.

Abstract: A filter condition indicator for a vacuum appliance having a filter includes a housing with a diaphragm dividing the housing into first and second chambers. One chamber receives a pressure indication from inside the filter, and the other chamber receives a pressure indication from outside the filter. An indicator device is activated by movement of the diaphragm in response to a pressure differential between the first and second chambers.