Abstract: Flow measuring device for ascertaining flow of a measured medium flowing through a measuring tube, which flow measuring device has a first housing for protruding into the measured medium, wherein the first housing has a first surface intended to face the measured medium, wherein the flow measuring device includes a second surface for bounding the measured medium, and wherein each separation between the first surface for bounding the first housing from measured medium, the second surface for bounding the measured medium and the first surface of the first housing amounts to at least 1 mm.

Abstract: Elements of a single beam-forming array of ultrasonic transducer elements are selectively activated to direct two or more ultrasonic beams to a series of acoustic mirrors mounted to or fabricated at known locations at an inside surface of the pipe. The ultrasonic beams traverse measurement path segments at known angles through a fluid flowing through the pipe before being received back at the single transducer array. Fluid flow velocity along the fluid flow path is calculated as a function of a difference in time-of-flight (TOF) along first and second ultrasonic beam paths after subtracting TOF components contributed by known-length non-measurement path segments. The difference in TOF results from an additive downstream fluid flow velocity vector component along a first measurement path segment and a subtractive upstream fluid flow velocity vector component along a second measurement path segment.

Abstract: To provide a fluid flow rate detection device which can be evaluated as adequate from a medical point of view. The velocity of a fluid flowing through a luminal organ in vivo is to be obtained. V?(r, ?)=w·V??+(1?w) V+? is calculated to obtain a calculated value V?(r, ?) of the flow rate regarding a component of the fluid in the direction perpendicular to the ultrasonic beam direction. Here, the weight w is a value proportional to the distance d from the wall on one side of the organ at least when the distance is smaller than a predetermined distance from the wall on the one side, and the weight is a value proportional to the distance d? from the wall on the other side of the organ at least when the distance is smaller than a predetermined distance from the wall on the one other side.

Abstract: [Object] To provide a method and an apparatus capable of measuring a pulsatingly fluctuating flow rate under a general condition, without needing electrical conductivity for a fluid, and without allowing a phase lag corresponding to a calculation time or attenuation or a phase lag resulting from a relation between pressure difference and flow rate to occur. [Means to Accomplish the Object] Ultrasonic waves are repeatedly transmitted with respect to a pulsatingly fluctuating fluid, while the ultrasonic wave being received, and a signal indicative of the transmission and receipt, and a signal indicative of a timing of the transmission and receipt are recorded. Alternatively, the ultrasonic wave is transmitted and received based on a preliminarily set timing signal, and the signal indicative of the transmission and receipt is recorded. These signals are used to determine flow rates and transmission and receipt timings to plot a pulsating fluctuation.

Abstract: Apparatus and methods for verifying temperature measurements in an ultrasonic flow meter. An ultrasonic flow metering system includes a passage for fluid flow, a temperature sensor, an ultrasonic flow meter, and a flow processor. The temperature sensor is disposed to provide measured temperature of fluid flowing in the passage. The ultrasonic flow meter is configured to measure transit time of an ultrasonic signal through the fluid. The flow processor is configured to 1) compute speed of sound through the fluid based on the transit time; 2) calculate a computed temperature of the fluid based on the speed of sound; 3) apply compensation, based on a historical difference between the computed temperature and the measured temperature, to a temperature verification parameter; and 4) determine, based on the temperature verification parameter, whether a current difference between the measured temperature and the computed temperature is within a predetermined range.

Abstract: A device for measuring the physical characteristics of a flow within a pipe is disclosed. In one exemplary embodiment, the device comprises a plug attached to two or more strut assemblies, each strut assembly comprising a forward strut, a rearward strut, and a skid having an inner surface that faces the plug, and one or more sensors located on the inner surface of the skid.

Abstract: A multimode flow meter can use both the time-of-transit of upstream and downstream ultrasonic signals and time for transmission of downstream-only signals to determine a flow velocity of a medium flowing through a conduit. Based on factors, such as previously computed flow velocity and signal-to-noise ratio of the upstream signal, a mode of operation may be switched and only the time for transmission of the downstream signals may be used to determine flow velocity. The multimode flow meter can compute cross-flow to reduce its effect on the determination of flow velocity.

Abstract: An ultrasonic flowmeter apparatus, which can be mounted on a conduit flowing a fluid whose flow rate is to be measured, has two housing halves coupled swingably about an axis. Free ends of the housing halves include a clamp mechanism for closing and locking the halves in position. The halves have formed therein grooves 1a and 2a, respectively, and a pair of ultrasonic wave transmission and reception elements are provided on an inner wall of the groove 1a. When the conduit is clamped between the grooves, the conduit is urged against the inner walls and deformed into a substantially square cross sectional configuration. An ultrasonic wave beam B is projected from one of the elements into a fluid passing through the conduit, the beam is reflected by an opposite surface of the conduit urged against the groove 2a, and the reflected beam is received by the other element.

Abstract: An ultrasonic flowmeter includes a plurality of ultrasonic wave elements attached to an outer wall of a pipeline through which a measurement target fluid flows, and configured to transmit and receive an ultrasonic signal, wherein at least one of the ultrasonic wave elements is an ultrasonic wave transmission element and is attached to the outer wall of the pipeline so that an ultrasonic wave transmission surface thereof is in parallel to a pipe axis direction of the pipeline, and another at least one of the ultrasonic wave elements is an ultrasonic wave reception element and is attached to the outer wall of the pipeline so that an ultrasonic wave reception surface thereof is in parallel to the pipe axis direction of the pipeline.

Abstract: The present invention relates to an ultrasound transducer assembly for an ultrasound flowmeter, comprising a one-part or multi-part housing (2), which is provided to be connected to a line carrying the medium to be measured, wherein the ultrasound transducer transmits ultrasound through the housing (2) and the ultrasound transducer assembly has the following features: an ultrasound transducer body (4, 7) with a first main surface on the side facing the medium and a second main surface on the side facing away from the medium, first, preferably planar, contact means for electrically contacting the first main surface of the ultrasound transducer body (4, 7), second, preferably planar, contact means for electrically contacting the second main surface of the ultrasound transducer body (4, 7), wherein the first contact means are located between the ultrasound transducer body (4, 7) and the housing (2), through which ultrasound is to be transmitted, of the ultrasound flowmeter.

Abstract: Flowmeter for a fluid, comprising a duct unit which forms the ducts of the flowmeter, the duct unit having a plurality of ducts in a measurement region, and at least one measuring device being arranged in one of these ducts, the duct unit comprising a dividing device with one or more dividing stages for apportioning the fluid flowing into the flowmeter to the ducts, the or each dividing stage comprising at least one damming element which apportions fluid flowing through an inflow duct to at least two subducts, characterized in that the dividing device and/or an accelerating device, which is arranged in at least one of the ducts between the dividing device and measurement region, are/is designed to accelerate the fluid in such a way that the fluid has a first flow velocity upstream of the dividing device and in the measurement region a second flow velocity which is at least 1.5 times as high, in particular at least twice as high.

Abstract: A multi-channel flow sensing system typically includes first and second flow-sensing transducers arranged in each channel. A data acquisition system is coupled to the first and second transducers of each of the channels. The data acquisition system is arranged to transmit and/or receive a sensing signal from at least one of the first and second transducers of each of the channels. The received sensing signals are sequentially converted and accumulated as data for billing in accordance with the measured flow within each channel. Using common components within the data acquisition system for measuring the various channels reduces costs and increases affordability in cost-sensitive areas.

Abstract: A method for determining the starting instant (t0) of a periodically oscillating signal response (E2; E2?), wherein the signal response comprises a first set of half periods (E2a-d; E2?a-d) having a polarity equal to a polarity of the first half period (E2a; E2?a) in the signal response, and a second set of half periods (E2e-h; E2?e-h) having a polarity opposite to the polarity of the first half period (E2a; E2?a) in the signal response. The method comprises the steps of: determining a peak half period (E2e; E2?f) as the half period with the highest amplitude in a selected one of the first and second sets; determining a zero-crossing instant (ZC1; ZC?1) of the signal response occurring a known time distance from the peak half period (E2e; E2?f); determining the starting instant (t0) of the signal response (E2; E2?) based on the zero-crossing instant (ZC1; ZC?1) and a relationship between the peak half period (E2e; E2?f) and the starting instant (t0).

Abstract: The invention relates to a method of operating an ultrasonic flow meter by digitally sampling received signals. Acoustic wave packets are transmitted through a measuring distance in opposite directions, and the received signals are digitized at a sampling frequency being below the Nyquist-limit of two times the signal frequency of the wave packet to generate digitized under-sampled signals 31. From the digitized under-sampled signals, the difference in propagation time along the measuring distance is determined.

Abstract: A flow sensor includes a conduit and an ultrasonic transceiver. The conduit has an inner surface and an outer surface. The inner surface defines a flow passage through which a fluid may flow in a flow direction. The ultrasonic transceiver is coupled to, and surrounds a portion of, the outer surface of the conduit. The ultrasonic transceiver is configured to transmit ultrasonic waves into the fluid that propagate in a direction that is parallel to the flow direction, receive ultrasonic waves, and supply sensor signals representative of the received ultrasonic waves.

Abstract: A method for estimating and correcting or at least reducing phase errors in received ultrasonic signals in an ultrasonic flow meter is disclosed, the method including the steps of: measuring one or more signals in the ultrasonic flow meter, which one or more signals depend on characteristics of one or more ultrasonic transducers in the ultrasonic flow meter, using the one or more measured signals for calculating an estimated phase error value, and using the estimated phase error value for correcting transmission times measured by the ultrasonic flow meter.

Abstract: A method of producing an ultrasonic flow meter having the steps of fabricating a tube made of a sound absorbing material. There is the step of machining in the tube a channel having a constant inner diameter through which fluid flows. There is a step of attaching the cylinder to the ultrasonic flow meter.

Abstract: In a method for determining the flow rate of fluids using the ultrasonic transit time method, the flow speed and therefrom the flow rate of the fluid is determined from the transit time of ultrasound signals through the measurement section. In order to take into account the change in the transmission function of the ultrasonic converters, which change acts as a drift of the measurement variable, the transmission function of the measurement section is determined at least approximately, and at least one ultrasonic transit time is corrected by means of a correction value that is determined from the group transit time of the transmission function.

Abstract: An ultrasonic flow sensor for detecting a flow of a fluid medium in a flow tube includes at least one first ultrasonic transducer, at least one second ultrasonic transducer, and at least one waveguide configured to conduct ultrasonic waves between the at least one first ultrasonic transducer and the at least one second ultrasonic transducer by reflection on walls of the waveguide, and to enable the fluid medium to flow through. The ultrasonic waves are able to propagate between the first ultrasonic transducer and the second ultrasonic transducer on at least two ultrasonic paths. Sound energies of the ultrasonic waves transmitted on the at least two different ultrasonic paths differ from one another by no more than a factor of 100.

Abstract: A method for operating an ultrasonic device comprising a first and second ultrasonic transducers, includes driving the first and second transducers at a driving frequency such that the first and second transducers generate a first and a second signals, respectively. The method also includes sensing the second signal at the first transducer to produce a first measurement signal and sensing the first signal at the second transducer to produce a second measurement signal. The method further includes identifying a first set of data-points in the first measurement signal and a second set of data-points in the second measurement signal. The method also includes generating a frequency data-series using the first set of data-points and a corresponding data-point in the second set of data-points. The method also includes performing statistical operations based on the frequency data-series and configuring an operating frequency for driving the first and second transducers using the operations.

Abstract: A straight tube ultrasonic flow meter includes a measuring unit disposed within a measurement space of a casing. The measuring unit has a straight tubular body for measurement through which a fluid for measurement flows and a pair of oscillators disposed around an outer circumference of the tubular body. The measuring unit is capable of measuring a flow rate of the fluid by obtaining a flow velocity of the fluid for measurement based on a difference in propagation time of ultrasonic waves from both directions detected between the oscillators. The measuring unit is fixed to the casing and connected to an external pipe with a measuring unit protecting joint interposed therebetween. The measuring unit protecting joint restricts movement of the measuring unit to a central side in the axial direction and rotation of the measuring unit with respect to the casing, and provides a fluid flow channel.

Abstract: A frame that is inserted into a gate valve slot which accesses a channel through which fluid flows so an ultrasonic flowmeter can measure the fluid flow through the channel. The frame includes a first arm axle that fits into the slot. The frame includes a first ultrasonic transducer in communication with the flowmeter that is attached to the first arm axle. The frame includes a second ultrasonic transducer in communication with the flowmeter. The second transducer is aligned with and upstream from the first transducer relative to the fluid flow and between which ultrasonic signals are emitted and received through the fluid flow and which the flowmeter uses to determine the fluid flow through the channel. The apparatus for measuring fluid flow in a channel is accessed through a gate slot. A method for measuring fluid flow in a channel that is accessed through a gate slot.

Abstract: A measuring system for determining and/or monitoring flow of a measured medium through a measuring tube, wherein the measuring system includes: at least one control/evaluation unit, which, based on ultrasonic measurement signals, or based on measurement data derived from the ultrasonic measurement signals, ascertains volume, and/or mass, flow of the measured medium flowing in the measuring tube; and a sensor housing, which surrounds a first ultrasonic sensor and at least a second ultrasonic sensor. At least the first ultrasonic sensor is seated shiftably in the sensor housing; wherein the measuring system further includes a sensor holder, which is securable on the measuring tube and includes a securement mechanism for the releasable securement of the sensor housing on the sensor holder. The sensor housing forms with the ultrasonic sensors a unit securable on the sensor holder and releasable from the sensor holder.

Abstract: Provided are an acoustic matching member with a fixed density, an ultrasonic transmitter/receiver unit with a high sensitivity, and an ultrasonic flow meter device which attains stable and high-accurate flow measurement. An acoustic matching member comprises hollow elements and a binding agent. The acoustic matching member is created by removing hollow elements having higher densities, hollow elements having cracks, etc., from hollow elements before sorting-out. Since the hollow elements having higher densities, the hollow elements having cracks, etc., are removed from hollow elements before sorting-out, it becomes possible to provide an acoustic matching member having fixed characteristics without being affected by a manufacturing lot and a transportation process of the hollow elements. An ultrasonic transmitter/receiver unit created using the acoustic matching member has fixed characteristics and is able to perform high-accurate flow measurement.

Abstract: Provided are a method and a device for determining a flow rate through a pipe. A first measurement device is provided which determines the flow profile of the fluid in a first region using a Doppler frequency shift measurement method, and a second measurement device is provided which determines the flow profile of the fluid in the pipe in a second region using a travel time measurement method.

Abstract: An ultrasonic flow metering system includes a condition monitor. For each chordal path of a plurality of chordal paths of an ultrasonic flow meter the condition monitor is configured to compute: 1) a reference chordal velocity ratio; 2) a predicted chordal velocity based on the reference chordal velocity ratio for the chordal path and measured flow velocities for all other chordal paths of the plurality of chordal paths; 3) a first estimated mean flow velocity for the ultrasonic meter, the first estimated mean flow velocity based on the predicted chordal velocity for the chordal path and the measured flow velocities for all other chordal paths of the plurality of chordal paths; and 4) for each other chordal path of the plurality of chordal paths, a predicted chordal velocity ratio based on the measured flow velocity for the other chordal path and the first estimated mean flow velocity.

Abstract: An ultrasonic flowmeter includes a measurement pipe through which a fluid flows, and two ultrasonic transceivers mounted on two transmitting bodies, respectively. The transmitting bodies are provided on outer side portions of the measurement pipe so as to be spaced from each other in an axis direction, and the measurement pipe and the two transmitting bodies are formed integrally with each other. The measurement pipe has a length, an inner diameter uniform in a length direction, and an arithmetic mean roughness Ra of an inner peripheral surface. The inner diameter is equal to or less than 5 mm, and the length of the measurement pipe is equal to or more than 30 mm. The arithmetic mean roughness Ra satisfies a relation of 0 ?m<Ra?0.2 ?m.

Abstract: The present invention is one that suppresses crosstalk caused by switching means adapted to switch transmission/reception between ultrasonic transceivers that are paired, and provided with: a first ultrasonic transceiver and a second ultrasonic transceiver; a transmission circuit that generates a transmission signal for vibrating the first ultrasonic transceiver or the second ultrasonic transceiver; a reception circuit that senses a reception signal from the first ultrasonic transceiver or the second ultrasonic transceiver; first transmission amplifying means adapted to amplify the transmission signal to the first ultrasonic transceiver; first reception amplifying means adapted to amplify a reception signal from the first ultrasonic transceiver; second transmission amplifying means adapted to amplify the transmission signal to the second ultrasonic transceiver; and second reception amplifying means adapted to amplify a reception signal from the second ultrasonic transceiver.

Abstract: Method comprises transmitting and receiving ultrasound signals (USS) in and counter direction of flow (ICDF) of controlled medium in pipeline (CMP); determining times of USS transmission ICDF of CMP and difference therebetween; forming time difference code; forming array of address codes corresponding to zero crossing moments of codes of USS passed ICF of CMP; determining zero crossing moment address code for codes of USS passed ICF of CMP closest to mutual correlation function (MCF) maximum address codes; selecting codes of USS passed ICDF of CMP corresponding to MCF maximum; forming MCF of selected part of codes of USS passed ICDF of CMP and signal shifted by 90° to primary USS; digitizing these MCF forming codes of time transmission of USS passed ICDF of CMP within sampling rate interval; determining accurate difference code of time intervals between USS passed ICDF of CMP; and determining CMP volume flow rate from a formula.

Abstract: An ultrasonic transducer for determining and/or monitoring flow of a measured medium through a measuring tube, which includes at least one piezoelectric element, at least one coupling element and at least one adapting, or matching, layer between the piezoelectric element and coupling element. The adapting, or matching, layer has a thickness smaller than a fourth of an uneven integer multiple of a wavelength of an ultrasonic signal being used.

Abstract: A vortex-shedding flowmeter uses two ultrasonic transducers to generate an acoustic beam at a selected carrier frequency. Vortices generate fluid oscillations that are detected when they pass through the beam and induce phase changes representative of fluid flow rate. In an improved vortex-shedding flowmeter each of the transducers is connected to a separate transformer and the outputs of the two transformers are interconnected to yield the phase change.

Abstract: Please replace the abstract that appears on page 32 of the specification with the following revised abstract which is submitted on a separate sheet.

Abstract: When a flow rate is equal to or more than a reference flow rate, a reference voltage is changed to a level capable of measuring stably to thereby realize the improvement of measurement accuracy at the time of a large amount of flow rate. A flow rate determination means compares a flow rate calculated by a flow rate calculation means with the reference flow rate. When the calculated flow rate is larger than the reference flow rate, the reference voltage set by a reference voltage setting means is changed, whereby the zero cross point can be detected stably at the portion where the degree of the influence of the change in the amplitude of the received signal is small. Thus, it is possible to provide a flow rate measuring device capable of measuring a flow rate stably with high accuracy even when a fluid flow is disturbed due to a large amount of flow rate.

Abstract: A system is provided with an ultrasonic flow meter. The ultrasonic flow meter includes a first ultrasonic transducer disposed about a fluid flow path, and a pressure balancing system configured to pressure balance the first ultrasonic transducer relative to a fluid flow along the fluid flow path.

Abstract: The present invention relates to an apparatus for estimating the air humidity within an oven cavity (14) by using ultrasound waves with at least two different frequencies (f1, f2). Said apparatus comprises at least one ultrasound transmitter (10) for generating the ultrasound waves, at least one ultrasound receiver (12) for receiving the ultrasound waves and at least one phase detecting device for detecting the phase (?1, ?2) of the ultrasound wave at the ultrasound receiver (12) relative to the same ultrasound wave with the same frequency (f1, f2) at the ultrasound transmitter (10).

Abstract: An ultrasonic wave transmitting and receiving unit includes: a piezoelectric member supporting plate; an acoustic matching member fixed to one surface of the piezoelectric member supporting plate; a piezoelectric member fixed to the other surface. Moreover, the ultrasonic wave transmitting and receiving unit includes: an insulating vibration suppressing member integrally formed in such a manner as to cover the piezoelectric member and the piezoelectric member supporting plate, wherein the insulating vibration suppressing member has a hole reaching the piezoelectric member supporting plate.

Abstract: A method of estimating the time of flight of a burst signal includes: receiving the burst signal; determining the slope of the phase characteristic of the Fourier transform of the received burst signal; and estimating the time-of-flight of the burst signal from the slope of the phase characteristic of the Fourier transform of the received burst signal.

Abstract: A wedge and a method for determining the speed of sound in the wedge is disclosed. The wedge includes a reflecting wall and is configured such that a portion of the main ultrasonic signal transmitted by an ultrasonic transducer is reflected and travels through the wedge back to the ultrasonic transducer. The speed of sound can be determined based on the distance traveled by, and the time of flight of, the main ultrasonic signal and reflected ultrasonic signal in the wedge.

Abstract: A flowmeter for detecting gas flow rates in a pipe includes a container configured to be attached to the pipe having a channel through which the gas flows, and a plurality of recesses that extend through the container and a plurality of housings. The flowmeter includes a plurality of transducers, with one transducer of the plurality of transducers disposed in each recess. The transducers transmit ultrasonic signals into and receive ultrasonic signals from the channel. The flowmeter includes a controller in electrical communication with the plurality of transducers which determines the gas flow rate through the channel by measuring transit times of signals transmitted by and received by the transducers. A housing for an ultrasonic transducer for a flowmeter which is inserted into a recess of a container that acoustically isolates the housing from the container. A method for detecting gas flow rates in a pipe.

Abstract: An ultrasonic flow meter includes a first ultrasonic sensor, a second ultrasonic sensor, a volume-flow operation portion, a temperature operation portion, a pressure operation portion, and a correction operation portion. The ultrasonic sensors transmit and receive a plurality of ultrasonic waves of different frequencies and are disposed on opposite sides of a flow channel in which fluid flows. The volume-flow operation portion calculates a volume flow of the fluid based on a propagation time difference of the ultrasonic wave. The temperature operation portion analyzes signals from one of the ultrasonic sensors and calculates a temperature of the fluid. The pressure operation portion analyzes signals from one of the ultrasonic sensors and calculates a pressure of the fluid. The correction operation portion corrects the volume flow with the temperature and the pressure.

Abstract: A flow sensor includes a conduit and an ultrasonic transceiver. The conduit has an inner surface and an outer surface. The inner surface defines a flow passage through which a fluid may flow in a flow direction. The ultrasonic transceiver is coupled to, and surrounds a portion of, the outer surface of the conduit. The ultrasonic transceiver is configured to transmit ultrasonic waves into the fluid that propagate in a direction that is parallel to the flow direction, receive ultrasonic waves, and supply sensor signals representative of the received ultrasonic waves.

Abstract: According to an embodiment of the present disclosure, an apparatus is configured to perform a solution process by supplying a processing solution from a processing solution supply source to the substrate held on a substrate holder via a flow path member and a nozzle at a flow rate equal to or less than 1 mL/sec. The apparatus includes a solution transfer unit configured to transfer the processing solution to the nozzle, and mounted to the flow path member, and an ultrasonic flowmeter mounted to the flow path member at a downstream side from the solution transfer unit. In this embodiment, a lower limit of a flow rate range which is measured by the ultrasonic flowmeter is equal to or less than 1 mL/sec.

Abstract: An ultrasonic, flow measuring device, comprising an ultrasonic transducer in a bore of a measuring tube, which ultrasonic transducer has an ultrasound window, wherein a guide vane is inserted into the bore of the measuring tube in front of the ultrasound window and perpendicular to the ultrasound window of the ultrasonic transducer.

Abstract: In a flow meter device of the present invention, a time measuring section of the flow meter device includes a first counter which starts counting at a starting point of measurement of propagation time; and a second counter which starts counting at an end point of the measurement of the propagation time, and performs counting at a higher speed than the first counter. A propagation time TO is finally obtained by subtracting time ?t which is measured by the second counter and passes from the end point until the first counter counts up, from time T which is measured by the first counter and passes from a starting point until the first counter counts up after the end point. A flow calculating section calculates a flow with high accuracy using the propagation time TO. Thus, lower electric power consumption can be achieved, and accuracy of measurement of flow can be improved.

Abstract: Flow measuring device for ascertaining flow of a measured medium flowing through a measuring tube, which flow measuring device has a first housing for protruding into the measured medium, wherein the first housing has a first surface intended to face the measured medium, wherein the flow measuring device includes a second surface for bounding the measured medium, and wherein each separation between the first surface for bounding the first housing from measured medium, the second surface for bounding the measured medium and the first surface of the first housing amounts to at least 1 mm.

Abstract: Switching a transmitting and receiving direction of two transducers (2,3) in the forward and the reverse direction, a time differential memory part (17b) storing a propagation time differential every K times a unit measurement process being executed, the propagation time differential being a differential between a propagation time of the ultrasonic wave signal in a forward direction and in a reverse direction, a flow rate calculating part (15) calculating a flow rate of a passing fluid based on a lump sum of propagation times in both the forward and the reverse directions obtained at least every K times of a unit measurement process being executed, an estimating part (18) estimating a change in a momentary flow rate of the fluid based on the time differential obtained every K times of the unit measurement process being executed and storing thereof in a time differential memory part (17b), thus obtaining an accurate flow rate and detecting the change in the momentary flow rate.

Abstract: A measurement arrangement comprises a clock generator (11) which can be coupled to an emitting ultrasonic transducer (13) and a mixing arrangement (12) for providing a first mixer output signal (SO1). The mixing arrangement (12) has a first input (18) which can be coupled to a receiving ultrasonic transducer (14) and a second input (19) which is coupled to the clock generator (11).

Abstract: The invention relates to an ultrasonic gas flow meter and corresponding method of verification, where the ultrasonic gas flow meter comprises at least one signal evaluation unit, memory, piping through which gas can flow, and ultrasonic transducers disposed on opposite sides of the piping; the ultrasonic gas flow meter is adapted to detect a flow velocity of the gas flowing through the piping. The method comprises a test procedure for verifying the operation of electronics associated with the ultrasonic gas flow meter wherein, when the test procedure is activated, test signals are triggered which replace the propagation times measured with predefined propagation times associated with an assumed gas flow velocity and the output of the evaluation unit is detected to see how the calculated gas flow velocity compares to the assumed gas flow velocity.

Abstract: A multimode flow meter can use both the time-of-transit of upstream and downstream ultrasonic signals and time for transmission of downstream-only signals to determine a flow velocity of a medium flowing through a conduit. Based on factors, such as previously computed flow velocity and signal-to-noise ratio of the upstream signal, a mode of operation may be switched and only the time for transmission of the downstream signals may be used to determine flow velocity. The multimode flow meter can computer cross-flow to reduce its effect on the determination of flow velocity.

Abstract: Ultrasonic flow rate measurement device includes measurement flow path in which a fluid to be measured flows, and a pair of ultrasonic vibrators that are disposed in directions such that a propagation path of an ultrasonic wave forms a V-shape relative to measurement flow path. Moreover, the device includes measurement circuit which measures a flow rate of the fluid to be measured by measuring a propagation time of the ultrasonic wave between the pair of ultrasonic vibrators, and inlet-side rectification part which is disposed, in the inlet side of measurement flow path, to stabilize the flow of the fluid to be measured. Furthermore, the device includes outlet-side coupling part which is disposed in the outlet side of measurement flow path, and signal lead-out part which outputs a flow rate value measured with measurement circuit.