Abstract: A connector for fastening a gas chromatography capillary column to chromatography equipment includes a securing nut and ferrule on a first portion of the connector for releasably holding the capillary column in a position relative to a second portion of the connector. The first portion rotates relative to the first portion and translates a limited amount relative to the first portion. A pin on the first portion extending into an annular groove around a circumference of the first portion may allow this rotation and limited translation. The second portion has a threaded end adapted to screw into the chromatography equipment with the first portion remaining relatively rotation free as the second portion is screwed into place.

Abstract: An apparatus for performing dissolved gas analysis on electrical insulating oil. The apparatus is connectable to a first oil source and a second oil source and has a respective sample cell for each source, an analysis cell and a gas analyser. Each sample cell is selectably connectable to said analysis cell to allow fluid communication therebetween, while the other sample cell is isolated from the analysis chamber. The apparatus allows dissolved gas analysis to be performed on samples from more than one source while minimizing the effects of cross-contamination between samples.

Abstract: An Interactive Mobile Aquatic Probing and Surveillance system. The system includes a remote aquatic or amphibious agent which is controlled by a typically land-based computer host. The agent is a field robot in the form of a comparatively small and inexpensive, untethered, self-propelled, aquatic or amphibious, non-submersible vehicle that preferably carries physical and water characteristic sensors, as well as other operational equipment for use on relatively small bodies of water and wetlands. The host interacts with a human operator and provides control commands to and receives data from the agent in real time via a wireless communication between the agent and the host. The control commands include guidance commands including navigational and propulsion commands as well as commands for operating the sensors and various other equipment carried by the agent.

Abstract: A sensor for detecting arsine includes a pair of electrodes separated by an electrode gap, and a layer of conducting polymer material positioned over and making electrical contact with the pair of electrodes, the layer of conducting polymer material being modified with a metal salt such that the electrical resistance of the conducting polymer material measured across the electrodes is responsive to changes in an amount of arsine to which the conducting polymer material is exposed.

Abstract: A knocking sensor which includes: a piezoelectric element; a support member having a support body portion, the support body portion including a support surface directly or indirectly supporting the piezoelectric element; and a resin coating covering the piezoelectric element and at least a part of the support member, the resin coating having an outside portion covering an outer circumference of the piezoelectric element and an outer circumference of the support body portion. The support body portion of the support member has a first engagement portion on the base end side thereof. The resin coating has a curved portion which extends from the outside portion toward the interfacial direction inner side, and curves toward the base end side of the support body portion. Further, the curved portion includes a second engagement portion which engages the first engagement portion.

Abstract: A device for conveying a substance that comprises: a first duct for containing the substance; an optical fiber connected to the first duct and extending along the duct, the optical fiber including several detection members spaced along its length, each detection member having a separate reflection spectrum that varies with the presence of the substance to be detected; a control device including a light source capable of emitting a light in the reflection spectrum of each detection member, a light receiver capable of detecting the light amplitude in the detection spectrum of each detection member, and an analysis module capable of determining the presence of a leak of the substance based on the light amplitude provided by the light receiver.

Abstract: To achieve a large measurement range from small up to larger leakage rates, a switchover from normal operation to gross operation occurs. In gross operation, the sucked-in gas flow is separated by different throttles, wherein the throttle that leads to the test gas sensor has a low flow rate. This manner of operation prevents a too large quantity of test gas from reaching the sensor surface and contaminating the sensor. In another alternative, in gross operation the test gas flows only across a part of the sensor surface. The other part is flushed.

Abstract: A sensor for detecting surface cracks in a component or structure. A preferred embodiment of the device comprises a flat body portion with a central hole through which a main structural bolt passes. The body portion has a throughway providing fluid communication between an exterior port and a substantially hermetically-sealed area on the structural surface being monitored. A crack which develops in the monitored area surrounding the bolt hole will cause venting of the hermetically-sealed area, in turn causing a change in fluid pressure that can be detected and/or measured to warn of the presence of the crack.

Abstract: A method of detecting a leak in a curing bladder during a tire curing process provides a curing bladder (40) and tire (42) in a tire mold structure (18). An inert tracer gas (48) is added to a pressurized gas such as nitrogen, with the nitrogen inflating the curing bladder so that the curing bladder engages a portion of the tire. The method detects whether the inert gas is present between the curing bladder and the tire while the curing bladder and tire remain in the tire mold structure. A curing bladder leak detection system (10) for a tire curing press (12) is also provided.

Abstract: At least one method, structure and apparatus used to measure tearing resistance of a commercial member. The method includes the use of full-scale testing methods and apparatuses to obtain unloading compliance measurements, which are used to generate a tearing resistance curve that includes the effects of geometry and considers data beyond the yield point of the commercial member. The commercial member may be a pipeline for carrying hydrocarbons.

Abstract: The present invention provides a method for measuring the viscosity and/or elasticity of a liquid by which accurate viscoelasticity measurement can be performed on a wide variety of liquids to be tested ranging from low viscosity liquids to high viscosity liquids, and viscosity and/or elasticity can be precisely determined from the viscoelasticity.

Abstract: A viscometer system to determine the viscosity of a fluid utilizes an existing flow cell, which maintains a calibrated constriction that is defined by a predetermined constant value K is disclosed. The viscometer system is adapted for use with the flow cell and includes a pair of pressure transducers with one at the input of the flow cell and another at the outlet of the flow cell. During operation, particles within the fluid pass through the flow cell, whereby the positional change of the particles over a predetermined period of time allows the system to calculate the flow rate of the fluid. The system also identifies the change in pressure of the fluid as it passes through the flow cell, such that the pressure change, flow rate, and the constant value K are processed to calculate the viscosity of the fluid being analyzed.

Abstract: A temperature control unit (216) for a column (201) of a fluidic device (200) for analyzing a fluidic sample, wherein the fluidic device (200) is adapted to conduct the fluidic sample through the column (201), the temperature control unit (216) being arranged to adjust a temperature of the fluidic sample in a flow path between an inlet 5 (207) of the column (201) and an outlet (208) of the column (201) so that a temperature adjustment effect occurs selectively in an interior of the column (201).

Abstract: A scanning probe system and method for using the same are disclosed. The system includes a probe that interacts with a specimen. The probe is caused to vibrate at a first frequency of the probe. A probe deflection signal indicative of an oscillation amplitude of the probe is generated and used to set the z-position probe position to maintain a property of the probe deflection signal at the first frequency at a predetermined value. A probe signal, having a DC and an AC component is applied between the specimen and the probe. The amplitude of a frequency component of the deflection signal at a mixing frequency of the first frequency and the second frequency is measured and used to generate an image or adjust the DC component.

Abstract: A method of analysis of secondary-air circuits in gas-turbine plants includes defining an equivalent fluid-dynamic network of a secondary-air circuit of a gas-turbine plant. The equivalent fluid-dynamic network includes a plurality of elements, organized in branches and connected to nodes. For at least one element of the secondary-air circuit a principal component of flow and at least one auxiliary component of flow are calculated.

Abstract: For monitoring a combustion process in an internal combustion engine wherein a fuel-air mixture is ignited with a high-frequency plasma it is provided to determine the impedance of the plasma. A high-frequency signal is applied to the resonator with a capacity that is so low that no arcing-over forms on the electrodes and the high-frequency current and the high-frequency voltage are measured. The impedance of the ignited mixture is determined from the high-frequency current and the high-frequency voltage.

Abstract: Provided is a clogging determining device and a clogging determining method for a reducing agent injection valve, which enable clogging of the reducing agent injection valve to be determined with high precision in further consideration of the individual difference of the system.

Abstract: A method for estimating the oxygen concentration in an internal combustion engine that includes, but is not limited to an intake manifold, an exhaust manifold, an EGR system, a throttle valve, an air mass sensor for measuring a fresh air flow ({dot over (m)}thr) entering the intake manifold through the throttle valve, and cylinders.

Abstract: A catalyst deterioration judgment device that can accurately perform a catalyst deterioration judgment by considering an oxygen density at downstream of an exhaust purification catalyst. The system reads outputs of an oxygen sensor and an ammonia sensor that are installed in downstream of an NSR catalyst when the catalyst is in an activate condition. When this read oxygen sensor output is equal to or more than a reference value and the ammonia sensor output is equal to or more than a reference value, it is estimated that ammonia oxidizing reaction does not occur under existence of oxygen in the NSR catalyst. In this case, the NSR catalyst is judged to be deteriorated.

Abstract: System intended for real-time supervision of engine test beds independent of the engine test bed likely to accommodate it. This supervision system mainly comprises a file describing equipments and drivers associated with various engine test beds, and a set of software drivers for controlling engine test bed equipments. These drivers are independent of the software operating environment and of the computer platform of the system. This system also comprises a real-time supervision software developed to read the information from the description file and to load the required drivers so that test configurations can be carried out in real time. These configurations come from a test configuration editor specific to the system and they are independent of the engine test bed. Application to the study of thermal engines or electric motors on test beds.

Abstract: A method for monitoring performance test stands having at least one load assembly, which is coupled to a test subject, such as an internal combustion engine, vehicle drive, or drivetrain, comprises ascertaining multiple, possibly derived parameters which characterize the current state of the test stand and evaluating them automatically in regard to the stability of the operating state of the test stand. In order to allow reliable recognition of instabilities in performance test stands of greatly varying configurations in the typical control modes and the reliable online monitoring of the stability of the control circuits on performance test stands in real time with CPU use which conserves resources as much as possible, the standardized parameters are weighted and consolidated into a single index which is characteristic for the current state, and this index is provided for the display and/or as a control variable for the real-time test stand controller.

Abstract: A thermal mass flow controller or mass flow meter having a novel sensor housing that reduces heat conduction from the housing mounting plate or base to the sensor itself. The housing also greatly minimizes the thermal gradient that can result from the uneven application of heat to the housing base. This reduction is accomplished in part by the use of one or more thermal isolation slots to isolate the upper portion of the housing (which holds the sensor) from the lower portion of the housing. Heat transfer to the sensor housing is also minimized by raising the middle portion of the bottom of the housing so that thermal contact is made between the base and the housing only at the two ends of the housing.

Abstract: A sensor includes: a silicon substrate having a hollow portion, which is arranged on a backside of the substrate; an insulation film disposed on a front side of the substrate and covering the hollow portion; a heater disposed on the insulation film, made of a semiconductor layer, and configured to generate heat; and an anti-stripping film for protecting the insulation film from being removed from the silicon substrate. The silicon substrate, the insulation film and the. semiconductor layer provide a SOI substrate. The hollow portion has a sidewall and a bottom. The anti-stripping film covers at least a boundary between the sidewall and the bottom of the hollow portion.

Abstract: A fluid detector includes a piezoelectric element that outputs a first ultrasonic signal in response to an input electrical signal and a lens with an upper portion and a lower portion. A housing is integral with an outer surface of the wall of a container and defines a cylindrical central bore for receiving the lens. The piezoelectric element is coupled to the upper portion of the lens so that the lens focuses the first ultrasonic signal toward the wall so that it enters the wall. An ultrasonic detector is disposed adjacent the outer surface of the wall, for receiving a second ultrasonic signal from the wall that results from the first ultrasonic signal and that is affected by the presence or absence of fluid. The ultrasonic detector generates an output electrical signal corresponding to the second ultrasonic signal.

Abstract: An apparatus for capacitive determining and/or monitoring of fill level of a medium in a container. The apparatus includes: A probe unit; a control unit, which supplies the probe unit with a drive signal; and an evaluating unit, which receives a response signal from the probe unit and which determines from the response signal a statement concerning fill level. Stored in the evaluating unit are at least a first and a second formula or a first and a second evaluating algorithm; and, in case accretion lies below a predetermined limit value, the evaluating unit determines the statement concerning fill level via a first formula and, in case accretion lies above the predetermined limit value, the evaluating unit determines the statement concerning fill level via a second formula.

Abstract: An apparatus for determining and/or monitoring a process variable of a medium in a container. including: a probe unit, which has a sensor electrode and a guard electrode; and an electronics unit, which supplies the sensor electrode with an activating signal and which supplies the guard electrode with a guard signal; An amplifying unit; and a limiting element arranged in series between the guard electrode and the output of the amplifying unit. The amplifying unit supplies via the limiting element the guard electrode with the guard signal; and the amplifying unit supplies via the limiting element the sensor electrode with the activating signal. The evaluating unit is provided, which determines and/or monitors the process variable based on an electrical current signal measurable at the sensor electrode, and the activating signal and/or the guard signal.

Abstract: A protective device for a humidity sensor protects the sensor from aggressive substances in a fluid to be analyzed. The protective device for the humidity sensor comprises a protective cap having openings that are covered with a membrane in such a manner that mass transfer between a measuring medium present in the environment and the interior of the protective cap can only take place through the membrane, said membrane including a plastic material which is highly permeable to water vapor, has high thermal stability and high corrosive resistance.

Abstract: The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass.

Abstract: A method and a machine for balancing vehicle wheels with weights (18), the method comprising stages of: using a video camera (5, 6, 206) to frame a portion of a surface of a hub (101) of a wheel on which a weight (18) is to be applied, locating, in images of the hub (101) taken by the camera (5, 6, 206), at least a balancing plane (E1, E2) which is perpendicular to a rotation axis (A) of the wheel, piloting at least a pick-up device (8, 9, 209) such as to direct the at least a pick-up device (8, 9, 209) onto a point (P1, P2) of the hub (101) belonging to the balancing plane (E1, E2), detecting, by means of the pick-up device (8, 9, 209) characteristic geometric parameters of the hub (101) at the balancing plane (E1, E2), measuring an imbalance of the wheel, calculating, by means of an electronic calculator (4, 204) an entity of at least a weight (18) to be applied to the hub (101) at the balancing plane (E1, E2), and also calculating an angular position (T1, T2) of the weight (18) in the balancing plane (E1,

Abstract: A sensor includes a proof mass suspended by a suspension beam, the suspension beam having a thickness less than a thickness of the proof mass.

Abstract: In a method for determining the relative position, velocity, acceleration, and/or the rotation center of a body displaceable in a three dimensional space, at least twelve linear acceleration sensors are provided and in each case arranged on a position which is stationarily fixed with respect to the body. At least one acceleration measurement signal is captured by the linear acceleration sensors. A position, velocity, acceleration, and/or rotation center signal is generated for the body from the acceleration measurement signal and data describing the position and orientation of the linear acceleration sensors in the body-fixed coordinate system.

Abstract: The invention provides a sensor comprising a frame, a plurality of beams extending inwardly from said frame, a weight portion supported by the beams, a piezoelectric-resistor formed on each beam and an insulating layer that covers the piezoelectric-resistor. The piezoelectric-resistor has at least one bend, and a metal wiring is located on the insulting layer positioned at the bend. The metal wiring is connected to the bend via at least two contact holes formed in the insulating layer. Contact holes are formed in the insulating layer positioned at both ends of the piezoelectric-resistor, and a bridge circuit wiring is connected to the piezoelectric-resistor via the contact holes.

Abstract: A vibration-type measuring device includes an exciter arrangement which exerts a time-dependent force with at least one sinusoidal component at an adjustable excitation frequency on a measuring tube, through which a medium can flow, and causes the measuring tube to oscillate. The measuring device includes first and second sensors which are fitted to the measuring tube at different locations. The first and second sensors output first and second measurement signals, respectively. The measuring device includes an evaluation unit which determines a first phase shift between the first and second measurement signals and uses the determined phase shift to determine a measurement variable of the medium. The measuring device includes a phase comparator, which determines a second phase shift between the force and the average value of the first and second measurement signals, and a frequency generator which sets the excitation frequency on the basis of the second phase shift.

Abstract: A sensor for examining a document of value (12) in a detection range (54) of the sensor comprises at least one electrical component (46) for converting electrical energy into sound waves and/or electromagnetic fields, in particular optical radiation, for examining the document of value (12) and/or for detecting sound waves and/or magnetic or electromagnetic fields, in particular optical radiation, from the document of value (12), so as to generate detection signals, and a holder for the component (46), having a recess (124) or a hole (60) for at least partially accommodating the component (46), in which the electrical component (46) is held, and on or in which at least one conductive path (74; 76) extends by means of which at least one electrical contact (68) of the electrical component (46) is contacted.

Abstract: The present invention relates to a method for determining the height of objects disposed on a conveying device, in which an ultrasonic sensor positioned in a specific relationship to the conveying device repetitively transmits ultrasonic pulses directed toward the conveying device and any objects disposed thereon to be detected, wherein the ultrasonic pulses are then reflected from a surface of the conveying device or from surfaces of the objects to be detected and are detected by the ultrasonic sensor, wherein from the moments of transmission and moments of detection of the ultrasonic pulses, delay times of the ultrasonic pulses are determined and the height of an object surface relative to the surface of the conveying device is determined from the delay times of the ultrasonic pulses reflected from a surface of an object.

Abstract: For precisely determining a position of an electronic pen using ultrasonic, only a direct wave arriving first at a reception device is detected without being affected by a reflected wave of an ultrasonic signal to count a propagation time of the electronic pen. An infrared signal including a trigger signal indicative of transmission timing and data indicative of an M-sequence initial condition, and an ultrasonic signal made into an M-sequence are simultaneously sent from the electronic pen in each fixed transmission cycle. The reception device disposed at a predetermined position receives the infrared signal from the electronic pen to generate an M-sequence model waveform from M-sequence initial condition data that the infrared signal includes. The reception device further receives the ultrasonic signal from the electronic pen to calculate a value of correlation between the ultrasonic signal and the above-described M-sequence model waveform.

Abstract: The invention relates to a device for controlling a material, said device comprising at least means for transmitting an electromagnetic signal at a carrier frequency Fp to illuminate the material and means for receiving the electromagnetic signal, characterized in that said device further comprises first means for modulating the electromagnetic signal at a frequency Fm1, said modulation means being arranged, on the signal path, between the transmission means and the material in order to spatially sample the emitted electromagnetic signal; second means for modulating the electromagnetic signal at a frequency Fm2, said modulation means being arranged, on the signal path, between the material and the electromagnetic signal reception means in order to spatially sample the electromagnetic signal passed through the material.

Abstract: A driver for applying an oscillating stress to a subject undergoing a medical imaging procedure, such as with magnetic resonance elastography (MRE), includes a passive driver located in the bore of the magnet and in direct contact with the skin of the subject. A remotely located active driver includes a linear motor and a sealed diaphragm that produces acoustic pressure waves in response to an applied current. The pressure waves are directed through a tube and into a chamber formed within the passive driver. Vibrations produced in response to the pressure waves create shear waves that are directed into the subject to aid in the imaging procedure.

Abstract: A method of monitoring pressure of a gas species up to at most a predetermined maximum pressure value is disclosed. The method includes exposing the gas species to transmission of laser light, periodically modulating the wavelength of the laser light over a wavelength band including at least one absorption line of the gas species, optoelectrically converting the transmitted laser light, thereby generating an electric output signal, performing at least one of first filtering the electric output signal with a filter characteristic having a lower cut-off frequency not lower than a transition frequency and of second filtering the electric output signal with a bandpass filter characteristic having an upper cut-off frequency not higher than the transition frequency and a lower cut-off frequency above the modulation frequency of the periodic wavelength modulation. The output of at least one of the filterings is evaluated as a pressure indicative signal.

Abstract: The invention relates to the field of multilayer ceramics and relates to ceramic pressure sensors, such as can be used, for example, for industrial process control. The object of the invention is to disclose ceramic pressure sensors that are mounted in a largely mechanically stress-free manner and have a long service life, and the production of which is more effective and more cost-effective. The object is attained with ceramic pressure sensors, comprising a support of tapes, wherein the tape(s) embody at least one cavity that is covered with at least one ceramic pressure membrane tape or in which a ceramic pressure membrane tape covering the cavity is located, and wherein the tape(s) have at least one supply line for the pressure connection to the cavity, and the tape composite is sintered.

Abstract: A smart coat with damage following feature for damage detection information, a detecting device and a damage detecting method using said smart coat, the smart coat could be set on a subject body and comprises a sensing layer, said sensing layer is composed of electrically-conductive material and has a thickness from 10 nanometers to 100 micrometers.

Abstract: Sensing strain in an adhesively bonded joint includes inducing a strain wave in the joint, and sensing a change in local magnetic characteristics in the joint.

Abstract: A device for axial load measurement on a mechanical control device (10) having rotating shaft (30) maybe used to derive a torque measurement. A mechanical control device (10) may comprise a valve actuator for fluid flow control devices. The load measurement device may include a beam (65a) operatively connected to a rotatable shaft and configured to deform under axial displacement of the shaft. A sensor (80) maybe coupled with the at least one beam (65a) and configured to produce an output signal related to the axial displacement of the shaft. The beam may be retained between two bearings (74) of the rotatable shaft at a first end, and fixed to the housing (120) of the mechanical control device at a second end. The first end of the beam (65a) may displace axially with the rotatable shaft. The beam (65a) may comprise a discrete segment of a uniform width and thickness.

Abstract: An apparatus and method for determination of susceptibility of asphalt concrete materials to moisture damage. An asphalt sample of known bulk specific gravity (density) is placed inside a chamber filled with water, which is capable of heating the sample to a pre-determined temperature. The chamber is pressurized by introduction of air pressure to a flexible membrane that decreases the volume within a chamber containing the sample and water, increasing the pore pressure in the sample. The pressure is then released and allowed to come to ambient pressure. This process is repeated a predetermined number of times (cycles). When a selected number of cycles are complete, the asphalt sample is removed from the chamber and its bulk specific gravity (density) measured again. The difference between the density before and after conditioning is an excellent method of rating the degree at which moisture would deteriorate asphalt samples due to introduction of moisture.

Abstract: A method for detecting the strain applied to a transmission chain includes positioning a strain gauge on an inwardly-facing surface of a first of a pair of opposed outer link plates, spacing the inwardly-facing surface of the first outer link plate from an outwardly-facing surface of a first of a pair of opposed inner link plates facing the first outer link plate, connecting the strain gauge into a bridge network and an electric circuit, and using an output of the electric circuit to determine the strain applied to the chain.

Abstract: Acoustic flow meter with dual flow measurements. At least some of the illustrative embodiments are flow meters comprising a spool piece that defines a central passage, a first plurality of transducer pairs mechanically coupled to the spool piece, a second plurality of transducer pairs mechanically coupled to the spool piece, and meter electronics electrically coupled to the first and second plurality of transducer pairs (the meter electronics configured to determine a first value indicative of fluid flow through the central passage, the first value determined using only signals of the first plurality of transducer pairs). The meter electronics further configured to determine a second value indicative of fluid flow through the central passage, the second value determined using only signals of the second plurality of transducer pairs.

Abstract: Coordination of measurement subsystems of a flow meter. At least some of the illustrative embodiments are flow meters comprising a spool piece that defines a central passage, a first plurality of transducer pairs mechanically coupled to the spool piece, a first control electronics electrically coupled to the first plurality of transducer pairs (the first control electronics configured to selectively activate each transducer pair of the first plurality of transducer pairs), a second plurality of transducer pairs mechanically coupled to the spool piece, a second control electronics different than the first control electronics (the second control electronics electrically coupled to the second plurality of transducer pairs, the second control electronics configured to selectively activate each transducer pair of the second plurality of transducer pairs). The first and second control electronics communicatively coupled and configured to coordinate activation of their respective transducer pairs.

Abstract: An ultrasonic fluid measuring device capable of improving a measuring accuracy is provided. An ultrasonic fluid measuring device 10 includes an ultrasonic measuring portion 20 in which a first ultrasonic transmitter-receiver 21 and a second ultrasonic transmitter-receiver 22 are provided to a measuring pass 14, and first to fifth pass partition plates 25 to 29 that are set in substantially parallel with an ultrasonic propagation path 24 that connects the first ultrasonic transmitter-receiver 21 and the second ultrasonic transmitter-receiver 22, whereby first to sixth flat passes 32 to 37 are laminated/formed in the measuring pass 14 by the pass partition plates 25 to 29.

Abstract: A flow sensor includes a fluid chamber configured to receive a fluid. A diaphragm assembly is configured to be displaced whenever the fluid within the fluid chamber is displaced. A transducer assembly is configured to monitor the displacement of the diaphragm assembly and generate a signal based, at least in part, upon the quantity of fluid displaced within the fluid chamber.

Abstract: A differential-pressure flow meter is capable of easily eliminating adhesion to an orifice of an extraneous material. The differential-pressure flow meter includes: a pair of pressure sensors provided on a straight pipe part of a main fluid channel; an orifice unit interposed between the pair of pressure sensors; a columnar orifice body provided on the main fluid channel to be detachable in a direction orthogonal to a flow direction of a fluid in the main fluid channel; and an orifice hole penetrating the orifice body in the flow direction of the fluid, wherein the orifice body is rotatable at a prescribed installation position to reverse an upstream side and a downstream side with respect to the orifice hole, and flow rate measurement is performed by converting into a flow rate a difference in pressure that is obtained from two pressure values sensed respectively by the pair of pressure sensors.