Abstract: An ultrasonic gas flow measurement device includes a dumbbell-shaped tube, a first ultrasonic transceiver, a second ultrasonic transceiver, a first cover part, a second cover part and a control unit. The dumbbell-shaped tube includes a central tube part, a first cone part, a first tube part, a second cone part and a second tube part, wherein the first tube part has a flow inlet, the second tube part has a flow outlet, the central tube part connects to the first tube part through the first cone part, and connects to the second tube part through the second cone part. The first ultrasonic transceiver installed inside the first tube part is used for transmitting or receiving ultrasonic signals. The second ultrasonic transceiver installed inside the second tube part is used for transmitting or receiving ultrasonic signals. The control unit is used to control the first and second transceivers.

Abstract: An ultrasonic flowmeter includes a meter body including a flow passage having wetted surfaces through which fluid flow is to be measured. The flowmeter includes a non-stick coating adhered to the wetted surfaces of the meter body. The flowmeter includes a first transducer and at least a second transducer arranged around the flow passage to transmit and receive ultrasonic energy. The flowmeter includes an electronic unit designed to generate and receive electronic signals from the transducers and to process the signals in order to compute information related to the fluid flow rate through the passage. A method for measuring fluid flow with an ultrasonic flowmeter. A method of making an ultrasonic flowmeter.

Abstract: First and second piezoelectric transducers 2 and 3 are fixed to a tubular main body 1 via first and second fitting bases 4 and 5. On front and rear surfaces of an end portion of each of the first and second piezoelectric transducers 2 and 3 are provided first and second electrodes 6 and 7. When the tubular main body 1 is secured to a circuit box, each of the end portions of the first and second piezoelectric transducers 2 and 3 is inserted between first and second contact members provided on the circuit box such that the first and second electrodes 6 and 7 are electrically connected to the first and second contact members, respectively to connect the first and second piezoelectric transducers 2 and 3 to the circuit box by one touch operation.

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. Each recess has a window made of metal. The flowmeter includes a plurality of transducers, with one transducer of the plurality of transducers disposed in each recess. The flowmeter includes a controller which determines the gas flow rate through the channel.

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: An ultrasonic flow rate measuring device includes a flow path, a partition plate that is inserted from an aperture to partition the flow path into plural sections, an ultrasound transmission body, plural ultrasonic transducers that are provided in positions facing a bottom plate such that an ultrasonic wave transmitted from one of the ultrasonic transducers through the ultrasound transmission body is reflected by the bottom plate and received by the other ultrasonic transducer, a measurement circuit that measures an ultrasonic propagation time between the plurality of the ultrasonic transducers; and a calculation circuit that obtains a flow rate of the target fluid based on a signal from the measurement circuit.

Abstract: The present invention provides an acoustic flow meter assembly (2) for pipes or open channels, said assembly including a frame (24) with a predetermined geometry. The frame has at least one user accessible port (36-42) with the at least one user accessible port (36-42) adapted to receive an interchangeable cartridge (44) which contains at least one acoustic transducer (46) to measure fluid velocity through said frame (24).

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. Each recess has a housing which contains pressure in the channel. Each housing has a window that is in acoustic communication with the channel. 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 through the window in the housing in which a transducer is disposed. 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.

Abstract: A flow meter for use in a flowing fluid medium includes at least one ultrasonic transducer and at least one measuring section having at least one flow pipe through which a fluid medium flows in a main direction of flow. The ultrasonic transducer is equipped to emit ultrasonic signals essentially parallel to the main direction of flow into the measuring section. The ultrasonic transducer is separated from the flow pipe by at least one thermal decoupling element. The thermal decoupling element is equipped to reduce heat transfer from the flow pipe to the ultrasonic transducer.

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: A system is provided with a pressure balancing system configured to protect a flow meter. The pressure balancing system includes a housing configured to surround a fluid conduit to define a fluid chamber around the fluid conduit. The fluid chamber is configured to house the flow meter. The pressure balancing system is configured to at least substantially balance fluid pressure internal and external to the fluid conduit via the fluid chamber.

Abstract: An ultrasonic transducer includes a piezoelectric element that is attached to a sonic lens, a support ring that holds the piezoelectric element, a flange, and a spoke. One end of the spoke is connected to the support ring and an opposing end of the spoke is connected to an inner surface of the flange. The sonic lens may be plastic film that coats the piezoelectric element.

Abstract: A measuring tube, a measuring system and a method for determining and/or monitoring flow through a measuring tube, comprising a measuring tube, on which ultrasonic transducers are releasably placeable. The ultrasonic transducers transmit and/or receive ultrasonic signals, which pass through the measuring tube approximately coaxially to the measuring tube axis.

Abstract: A system(s) and method(s) of testing the foam delivery system(s) of fire suppression systems. Systems are adapted to test the foam delivery system of a fire suppression system under test while minimizing the release of foam to the environment.

Abstract: A fluid flow meter estimates the velocity of water or another fluid flowing through pipe by comparing measurements of the water velocity to one or more pre-determined templates. The fluid flow meter may collect measurement signals from one or more flow sensors (e.g., ultrasonic transducers), estimate the fluid velocity or flow rate by comparing the measurement signals to the template(s), and either store the comparison results in local memory, transmit the results to a remote memory or server, or both. In some embodiments, the fluid flow meter transmits the results to a server via a wireless interface (e.g., a Zigbee, Bluetooth, or Wi-fi interface). The transducers and processing system can be powered by a battery, a power line, or, for manifolds installed outdoors, a solar cell. Example transducers and processing systems may also have a passive wake-up feature for power reduction; that is, they may only draw power when water or another fluid flows through the pipe.

Abstract: A flow-rate measurement device includes a first transducer and a second transducer which are provided in a fluid flow path to transmit and receive an ultrasonic signal, a timer unit which measures a propagation time of the ultrasonic signal propagating between the first transducer and the second transducer, and a flow-rate calculation unit which executes a unit measurement step a predetermined number of times and calculates a flow rate of a fluid flowing in the fluid flow path on the basis of the propagation times measured the predetermined number of times, the unit measurement step being an operation in which a direction of transmission to reception between the first transducer and the second transducer is switched and the timer unit measures the propagation times of the ultrasonic signal in both directions.

Abstract: The present invention provides an acoustic flow meter assembly (2) for pipes or open channels, said assembly including a frame (24) with a predetermined geometry. The frame has at least one user accessible port (36-42) with the at least one user accessible port (36-42) adapted to receive an interchangeable cartridge (44) which contains at least one acoustic transducer (46) to measure fluid velocity through said frame (24).

Abstract: First and second piezoelectric transducers 2 and 3 are fixed to a tubular main body 1 via first and second fitting bases 4 and 5. On front and rear surfaces of an end portion of each of the first and second piezoelectric transducers 2 and 3 are provided first and second electrodes 6 and 7. When the tubular main body 1 is secured to a circuit box, each of the end portions of the first and second piezoelectric transducers 2 and 3 is inserted between first and second contact members provided on the circuit box such that the first and second electrodes 6 and 7 are electrically connected to the first and second contact members, respectively to connect the first and second piezoelectric transducers 2 and 3 to the circuit box by one touch operation.

Abstract: An acoustic matching member is fitted to a main body in a pair of ultrasonic transmitter/receivers. The acoustic matching member includes a matching member equipped with a porous body adhered tightly to an acoustic-wave emission surface of the main body. A dense layer is stacked on a surface of the porous body and includes a thermosetting resin and first flowability-diminishing particles. A sidewall member is adhered tightly to the acoustic-wave emission surface and an end face of the porous body.

Abstract: A method for determining an operational condition of a particle detection system including at least one sample inlet for receiving a sample flow from a monitored region. The method includes the step of conducting an upstream measurement of a flow rate through the at least one sample inlet.

Abstract: A coupling element for an ultrasonic, flow measuring device, wherein the coupling element has a pedestal with a bearing surface, on which bearing surface a piezoelement is applied. The pedestal is an integral component of the coupling element.

Abstract: A system and method for ultrasonic flow metering. In one embodiment, an ultrasonic flow metering system includes a passage for fluid flow and a plurality of ultrasonic flowmeters. Each of the ultrasonic flowmeters includes a pair of ultrasonic transducers, and a flow processor. The pair of ultrasonic transducers is configured to form a chordal path across the passage between the transducers. The flow processor is coupled to the ultrasonic transducers. The flow processor is configured to measure the fluid flow through the spool piece based on outputs of the transducers of all of the ultrasonic flowmeters.

Abstract: An ultrasonic phase-shift detection device includes a clock generator, a divider, a first counter, a comparator, a phase detector and a second counter. The divider is provided for dividing the clock signal to generate ultrasonic signals. The comparator is provided for comparing the counting value of the first counter and a predetermined number. The phase detector is provided for comparing the phase shift between different ultrasonic signals. The second counter is provided for counting to generate the digital result signal.

Abstract: An ultrasonic flow meter for measuring the flow of a fluid through a pipeline comprises a spool piece including a throughbore and a transducer port. The transducer port extends along a central axis from an open end at the throughbore to a closed end distal the throughbore. In addition, the flow meter comprises an acoustic transducer disposed in the transducer port. The transducer includes a piezoelectric element. Further, the flow meter comprises a drain port in fluid communication with the transducer port. The drain port is axially positioned between the open end and the closed end of the transducer port. Still further, the flow meter comprises a drain conduit having an inlet end coupled to the drain port and an outlet end opposite the inlet end. The drain port is configured to drain a liquid from the transducer port into the inlet end of the drain conduit.

Abstract: The present invention pertains to a flow conditioner for displacing and mixing fluid flow to minimize the effects of thermal gradients on the accuracy of a transit time ultrasonic flowmeter and defines an envelope in a cross sectional direction in a pipe having a first ramp adapted to be disposed in the pipe and extending from the outside of the envelope inward toward the center of the pipe in a downstream direction with respect to the fluid flow and forming an angle between 0° and 90° relative to the pipe's inner surface. The conditioner has a second ramp adapted to be disposed in the pipe and in juxtaposition with the first ramp, the second ramp extending from the outside of the envelope inward toward the center of the pipe in an upstream direction with respect to the fluid flow and forming an angle between 0° and 90° relative to the pipe's inner surface. An apparatus for determining fluid flow in a pipe having ultrasonic transducer sites. A method for determining fluid flow in a pipe.

Abstract: A measuring system and method for determining and/or monitoring the flow of a measured medium through a measuring tube with a first ultrasonic sensor and at least a second ultrasonic sensor. The first Ultrasonic sensor is placeable in a first region of the measuring tube, and the second ultrasonic sensor is placeable in a second region of the measuring tube. The ultrasonic signals transmittable through the measured medium from the first ultrasonic sensor are receivable by the second ultrasonic sensor, and the ultrasonic signals transmittable through the measured medium from the second ultrasonic sensor are receivable by the first ultrasonic sensor. A control/evaluation unit ascertains the volume flow and/or the mass flow of the measured medium flowing in the measuring tube by means of a travel-time difference method.

Abstract: Provided are an ultrasonic fluid-measuring apparatus and an ultrasonic fluid-measuring apparatus that can prevent the disturbance from occurring in the ultrasonic waves due to disturbance of a fluid. An ultrasonic fluid-measuring structure includes an ultrasonic measuring section adjacent to a channel member. The channel member includes a first ultrasonic wave input/output section and a second ultrasonic wave input/output section provided in a first side wall part, and a reflecting surface provided on an inner surface of the second side wall part. Further, it is configured so that the first ultrasonic wave input/output section and the second ultrasonic wave input/output section are adjacent to each other, and an ultrasonic wave transmission membrane through which the ultrasonic waves pass covers together both the first ultrasonic wave input/output section and the second ultrasonic wave input/output section.

Abstract: Provided are a channel member and an ultrasonic fluid-measuring apparatus that can prevent the disturbance from occurring in the ultrasonic waves due to disturbance of a fluid. A channel member (15) includes a first side wall part (21) and a second side wall part (22) that are parallel to each other, a first ultrasonic wave input/output section (32) and a second ultrasonic wave input/output section (33) provided in the first side wall part, a reflecting surface (35) provided on an inner surface of the second side wall part, and an ultrasonic wave transmission membrane (38) that covers the first ultrasonic wave input/output section and the second ultrasonic wave input/output section and transmits ultrasonic waves (36, 37) therethrough.

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: A system is provided with a pressure balancing system configured to protect a flow meter. The pressure balancing system includes a housing configured to surround a fluid conduit to define a fluid chamber around the fluid conduit. The fluid chamber is configured to house the flow meter. The pressure balancing system is configured to at least substantially balance fluid pressure internal and external to the fluid conduit via the fluid chamber.

Abstract: An ultrasonic transducer for a pipe includes an ultrasonic source which produces plane waves. The transducer includes a housing having a face at least a portion of which is curved through which the plane waves produced from the source disposed in the housing are emitted and directed outward towards the pipe's interior wall so a full cross-section of the pipe's interior can be measured. A flow meter for detecting fluid flow rates in a pipe. A method for detecting fluid flow rates in a pipe.

Abstract: A flowmeter for detecting fluid flow rates in a pipe includes a tube having a channel disposed in the pipe through which fluid in the pipe flows. The flowmeter includes an upstream transducer in contact with the pipe and positioned so plane waves generated by the upstream transducer propagates through the channel. The flowmeter includes a downstream transducer in contact with the pipe and positioned so plane waves generated by the downstream transducer propagate through the channel and are received by the upstream transducer which produces an upstream transducer signal. The downstream transducer receives the plane waves from the upstream transducer and provides a downstream transducer signal. The flowmeter includes a controller in communication with the upstream and downstream transducers which calculate fluid flow rate from the upstream transducer signal and the downstream transducer signal. A method for detecting fluid flow rates in a pipe.

Abstract: Apparatus and method for non-invasively determining the level of a constituent of a patient's blood drawn though an elastomeric tubing to a dialysis machine deforms the tubing in the slot of a measuring head having two points of different transverse length with a transmit/receive sensor at each point that transmits a signal through the tubing and the blood and is reflected back to it from the tubing internal wall. The round trip transit time of the signal at each sensor is measured and the blood sound velocity is calculated from the two round trip transit times and the differential of the transverse lengths at the two points. Blood hematocrit level, which is related to blood volume, is calculated from the calculated sound velocity and an empirical relationship.

Abstract: A method and apparatus is disclosed that guides a user through a sequence of steps that will allow the user to complete a predefined task using the flow meter. The steps include: selecting a predefined task, displaying a sequence of steps that directs the user through a process for using the Coriolis flow meter to complete the predefined task, and operating the Coriolis flow meter in response to the sequence of steps to complete the predefined task.

Abstract: A system and method for measurement of flow parameters in a sewer pipe that may be partially or completely filled. Flow parameters may include flow velocity, flow volume, depth of flow and surcharge pressure. Measurements are taken from a sensor head installed on the inside of the pipe at the top of the pipe approximately the larger of at least 1 foot or 1 pipe diameter upstream of a pipe opening. Flow velocity may be measured by two different technologies. The technology employed depends on whether or not the pipe is full. If the pipe is not full then flow velocity may be measured, for example, using a wide beam, ultrasonic, diagonally downward looking Doppler signal that interacts with the surface of the flow. If the pipe is full, then flow velocity may be measured using, for example, an average velocity Doppler sensor, a peak velocity Doppler sensor or an ultrasonic velocity profiler.

Abstract: The present invention provides an acoustic flow meter assembly (2) for pipes or open channels, said assembly including a frame (24) with a predetermined geometry. The frame has at least one user accessible port (36-42) with the at least one user accessible port (36-42) adapted to receive an interchangeable cartridge (44) which contains at least one acoustic transducer (46) to measure fluid velocity through said frame (24).

Abstract: A flowmeter for detecting gas flow rates in a pipe. The flowmeter includes a container configured to be attached to the pipe having a channel through which the gas flows, and a plurality of recesses. Each recess has a window made of metal that is in acoustic communication with the channel. 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 through the window in the housing recess in which a transducer is disposed. The flowmeter includes a controller in electrical communication with the plurality of transducers which determines the gas flow rate through the channel from signals received from the transducers. A housing for an ultrasonic transducer for a flowmeter which is inserted into a recess of a container. A method for detecting gas flow rates in a pipe. A transducer for an ultrasonic flowmeter.

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. Each recess has a housing which contains pressure in the channel. Each housing has a window that is in acoustic communication with the channel. 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 through the window in the housing in which a transducer is disposed. 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.

Abstract: An ultrasonic transducer for a pipe includes an ultrasonic source which produces plane waves. The transducer includes a housing having a face at least a portion of which is curved through which the plane waves produced from the source disposed in the housing are emitted and directed outward towards the pipe's interior wall so a full cross-section of the pipe's interior can be measured. A flow meter for detecting fluid flow rates in a pipe. A method for detecting fluid flow rates in a pipe.

Abstract: An ultrasonic gas flow measurement device includes a dumbbell-shaped tube, a first ultrasonic transceiver, a second ultrasonic transceiver, a first cover part, a second cover part and a control unit. The dumbbell-shaped tube includes a central tube part, a first cone part, a first tube part, a second cone part and a second tube part, wherein the first tube part has a flow inlet, the second tube part has a flow outlet, the central tube part connects to the first tube part through the first cone part, and connects to the second tube part through the second cone part. The first ultrasonic transceiver installed inside the first tube part is used for transmitting or receiving ultrasonic signals. The second ultrasonic transceiver installed inside the second tube part is used for transmitting or receiving ultrasonic signals. The control unit is used to control the first and second transceivers.

Abstract: Methods and systems for detecting deposit buildup within an ultrasonic flow meter are disclosed. At least some of the illustrative embodiments are ultrasonic flow meters comprising a spool piece configured to couple within a flow of fluid, a first transducer pair mechanically mounted to the spool piece and configured to fluidly couple to the flow of fluids (wherein the first transducer pair comprises an upstream transducer and a downstream transducer in operational relationship to the upstream transducer and defines a first chord there between), and electronics electrically coupled to the first transducer pair. The electronics is configured to detect deposit buildup over an inner surface of the ultrasonic flow meter.

Abstract: The present invention pertains to a flow conditioner for displacing and mixing fluid flow to minimize the effects of thermal gradients on the accuracy of a transit time ultrasonic flowmeter and defines an envelope in a cross sectional direction in a pipe having a first ramp adapted to be disposed in the pipe and extending from the outside of the envelope inward toward the center of the pipe in a downstream direction with respect to the fluid flow and forming an angle between 0° and 90° relative to the pipe's inner surface. The conditioner has a second ramp adapted to be disposed in the pipe and in juxtaposition with the first ramp, the second ramp extending from the outside of the envelope inward toward the center of the pipe in an upstream direction with respect to the fluid flow and forming an angle between 0° and 90° relative to the pipe's inner surface. An apparatus for determining fluid flow in a pipe having ultrasonic transducer sites. A method for determining fluid flow in a pipe.

Abstract: A flow measuring apparatus measures a fluid flow within a conduit including a wall. The apparatus includes a transducer arrangement including at least two transducers for alternately emitting and receiving ultrasonic radiation through the conduit wall and the flow. The apparatus also includes a signal processing arrangement for generating signals to excite the transducer arrangement and for processing received signals provided by the transducer arrangement for generating output signals from the signal processing arrangement indicative of properties of the flow. The transducer arrangement in cooperation with the conduit provides a first path for Lamb-wave ultrasonic radiation coupling directly from a first of the at least two transducers, to a second of said at least two transducers to generate a first received signal.

Abstract: Provided is a straight tube ultrasonic flow meter capable eliminating error causes in the ultrasonic wave measurement, and having further improved measurement accuracy. A straight tube ultrasonic flow meter (1) includes: a measuring unit (20) disposed within a measurement space (13) of a casing (10), the measuring unit having a tubular body for measurement (21) as a straight tube through which a fluid for measurement flows and a pair of oscillators (22a, 22b) disposed around an outer circumference of the tubular body for measurement (21) at a predetermined interval along an axial direction, the measuring unit (20) 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 wave from both directions detected between the oscillators (22a, 22b).

Abstract: An ultrasonic liquid sensor for detecting liquid in a tube having sidewalls includes a first intermediate mounting plate held in physical communication with a first sidewall of the tube, a second intermediate mounting plate held in physical communication with the second sidewall of the tube. The plates are configured to allow the ultrasonic signal to pass therethrough. The sensor also includes a first and a second transducer element. The first and second transducer elements are mounted to the intermediate mounting plates and are configured to receive the ultrasonic signal passing through the sidewalls of the tube as well as the intermediate mounting plates to determine the presence or absence of liquid in the tube. The sensor can be enclosed in a self-contained unit and a support assembly can be used and formed of metal material or non-metal material to interface with the sensor and a secondary circuit.

Abstract: A measuring tube, a measuring system and a method for determining and/or monitoring flow through a measuring tube, comprising a measuring tube, on which ultrasonic transducers are releasably placeable. The ultrasonic transducers transmit and/or receive ultrasonic signals, which pass through the measuring tube approximately coaxially to the measuring tube axis.

Abstract: The invention relates to a method for determining the temporal position of a wave packet (31) in a flow measuring apparatus, and to a flow measuring apparatus. The method includes the sampling of the wave packet at a plurality of points in time, wherein a measured value is created at each point in time. Subsequently, a sum of products (43, 54, 55, 63, 64) is calculated, wherein each product is calculated for a determined point in time from a plurality of points in time and each product is the product of a value of a compare function (44, 53, 56, 61, 62) at the determined point in time and the measured value at the determined point in time. Finally, the temporal position of the wave packet is calculated from the sum of products.

Abstract: An ultrasonic measuring arrangement (1) for the flow, speed of sound, density, viscosity and/or temperature measurement of flowing media, including a measurement tube (2) having a measurement section (3), with the tube being disposed in an area of a measurement housing (4). At least two ultrasound transmitting receivers are spaced apart as sensors for sound transmission through the measurement section (3) in the direction of flow of a medium, and opposite thereto, and for signal recording. In order to provide an ultrasonic measuring arrangement (1) that is simple and inexpensive to produce, has a small nominal diameter and permits direct sound transmission through the measurement section (3) at as low a transmission output as possible, the measurement tube (3) is configured together with the measurement housing (4) as a one-piece housing part (5) free of seals and seams, and the sound path form an acute angle with the flow direction of the medium.

Abstract: A method and apparatus for determining flow in an aspirated smoke detector system includes a plurality of sampling pipes in fluid communication with a smoke detector, a flow rate detector in at least one of the sampling pipes that senses a signal transmitted between a first and second signal transceiver, wherein the first transceiver transceives signals in at least two of the sampling pipes.

Abstract: A flow measuring apparatus (300, 500) measures a fluid flow (130) within a conduit (120) including a wall (110). The apparatus (300, 500) includes a transducer arrangement including at least two transducers (100A, 100B) for alternately emitting and receiving ultrasonic radiation through the conduit wall (110) and the flow (130). The apparatus (300, 500) also includes a signal processing arrangement (310) for generating signals to excite the transducer arrangement (100A, 100B) and for processing received signals provided by the transducer arrangement (100A, 100B) for generating output signals from the signal processing arrangement (310) indicative of properties of the flow. The transducer arrangement (100A, 100B) in cooperation with the conduit (120) provides a first path (200) for Lamb-wave ultrasonic radiation coupling directly from a first of the at least two transducers (100A, 100B), to a second of said at least two transducers to generate a first received signal.