Abstract: Apparatus for ascertaining and/or monitoring volume- or mass-flow of a medium flowing through a pipeline in the direction of the longitudinal axis of the pipeline. The apparatus includes at least one ultrasonic sensor containing at least one sound-producing element and an interfacing shoe and emitting, respectively receiving, ultrasonic measurement signals at an incidence/emergence angle into, respectively out of, the pipeline A first adjusting mechanism is provided, which is so embodied, that the incidence/emergence angle of the ultrasonic sensor is adjustable in predetermined limits. The apparatus further includes a control/evaluation unit, which ascertains the volume- or mass-flow of the medium in the pipeline on the basis of the travel-time difference method, the cross-correlation method or the Doppler method.

Abstract: A method for operating a measuring apparatus (1) for determining the flow rate of a flowable medium through a measuring section (3) is provided, wherein the measuring apparatus (1) has, as sensors, two ultrasonic transceivers (4), which are arranged spaced apart from one another, for the purpose of ultrasonic testing of the measuring section (3) in and counter to the flow direction and for the purpose of picking up signals and is operated with an ultrasonic phase difference method.

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: Disclosed is an ultrasonic Doppler flow measurment system that achieves flow measurement regardless of the temperature of a fluid. A temperature sensor 7 is combined with a pipe 1 to measure the temperature of a fluid 2. A controller 9 calculates a frequency that will cause cavitation when an ultrasonic transducer 4 exerts an ultrasonic vibration on the fluid 2 on the basis of a temperature measured by the temperature sensor 7 and controls a sinusoidal oscillator 6.

Abstract: An ultrasonic flow sensor is used in particular for measuring the volumetric or mass flow of a fluid in a pipe. The sensor includes at least one ultrasonic transducer which is capable of emitting and receiving ultrasonic signals. An ultrasonic flow sensor, having in particular a simple and cost-effective construction and which functions according to the principle of beam drift, includes an array of a plurality of ultrasonic transducers which is positioned on one side of the pipe, a reflective surface lying opposite the array on which the emitted ultrasonic signals are reflected, and a receiver electronic system which evaluates the ultrasonic signal received from the ultrasonic transducers.

Abstract: An apparatus for determining a characteristic for a fluid in a tube, the apparatus including a force applying system to cause a change in a transverse dimension of a segment of the tube, wherein the change in the transverse dimension is reversible, and an ultrasonic system that comprises a single transducer for launching and receiving ultrasonic signals. Ultrasonic signals propagate through the tube along colinear paths of different lengths that are orthogonal to the tube wall. At least one of the paths is located entirely within the segment. Each of the ultrasonic signals propagates through the tube wall in a first wall region and reflects from an inner surface of a second wall region. Path length differences between the paths are determined, and transit times are determined for each of the ultrasonic signals. The characteristic is determined based on information including the path length differences and the transit times.

Abstract: An ultrasonic sensor has at least two ultrasonic converters for transmitting and receiving ultrasonic signals, connected with a transmitting circuit and a receiving circuit. A switching device is provided, by which the ultrasonic converters are connected in series when in the transmission mode, and they are separated from each other when in the receiving mode.

Abstract: Flowmeter comprising at least two ultrasonic transducers that are mounted on a container which is penetrated by a medium in a certain direction of flow. The ultrasonic transducers alternately transmit and receive ultrasonic test signals in the direction of flow and counter to the direction of flow. The flowmeter further comprises a control/evaluation unit which determines and/or monitors the volume flow of the medium inside the container based on the difference in the travel time of the ultrasonic test signals propagating in the direction of flow and counter to the direction of flow. The ultrasonic transducers are configured such that they transmit and receive ultrasonic test signals or sound fields having a large aperture angle or a great beam expansion.

Abstract: An ultrasonic flow sensor, in particular for determining the flow velocity of a medium flowing through a pipeline, has at least one ultrasonic converter for transmitting and/or receiving ultrasonic signals, an oscillator, which is connected with the ultrasonic converter, and an evaluation unit, which determines a phase shift of the ultrasonic signal that was received, with respect to a reference signal. The evaluation unit includes a plurality of quadrature demodulators, which operate with different demodulation frequencies and each determine phase information about the ultrasonic signal that was received, and when a vernier unit is provided, which determines—based on the individual pieces of phase information—a phase angle or a quantity proportional thereto.

Abstract: A measurement control section comprises a time measuring section for controlling an operation of measuring a travel time of an ultrasonic wave. The measurement control section operations, based on a high rate clock signal supplied from a ceramic oscillation circuit during the time measuring operation. A clock control section stops the high rate clock signal supplied from the ceramic oscillation circuit every time when the time measuring section completes its time measuring operation, and uses a low rate clock signal supplied from a quartz oscillation circuit to count a standby time between the end of measuring the travel time and the start of carrying out the next measuring operation.

Abstract: A measurer for measuring a flow rate of a medium which may be multi-component or heterogeneous, independently of the medium, a signal-generating unit generating a transmit signal on the basis of a reference signal of a signal generator and transmitting same by means of a stimulator via the flowing medium. This signal is received by a sensor and passed on to an evaluating unit which is implemented to determine a signal transfer time based on a plurality of mutually corresponding locations of a waveform of the receive signal and the waveform corresponding to the reference signal and the flow rate of the medium based on the signal transfer time and the certain distance between the stimulator and the sensor.

Abstract: An ultrasonic flow rate meter and a method for measuring the flow rate with the aid of ultrasound are described, having at least two ultrasonic transducers situated offset in a flow channel in the flow direction for transmitting and receiving ultrasound wave packets, so that ultrasound propagation times from one of the ultrasonic transducers to the other, and vice-versa, can be determined in an electronic part, and having a pressure sensor associated with the flow channel for determining the pressure in the flow channel. Measured values for an engine control that is as accurate as possible are determinable by accurately detecting the incoming air in the intake of a motor vehicle internal combustion engine.

Abstract: A flowmeter includes: a transit time method unit having a sensor and a reception signal amplification control unit and a flow rate calculation unit which are connected to the sensor via a sensor selector switch; a pulse Doppler method having a reception signal amplification control unit and an integration calculation unit which are connected to the sensor; a transmission/reception timing control unit common to them; a measurement method selection control unit for controlling switching between the transit time method unit and the pulse Doppler method unit, and parallel operation; and a measurement value output selector switch for selecting the output of the transit time method unit and the pulse Doppler method unit. That is, the single flowmeter can perform flow rate measurement by the transit time method having no restriction on the measurement range as well as by the pulse Doppler method having an upper limit of the measurement range but enabling a highly accurate measurement.

Abstract: Pipeline including a system for monitoring fluid flowing through the pipeline includes a conduit defining an interior and at least one sensor assembly arranged in the interior. Each sensor assembly includes an energy generating system and at least one flow measuring device coupled to the energy generating system to be powered thereby. The flow measuring device provides information about flow of fluid in the conduit. The information may be transmitted to a remote monitoring location via a telematics or communications unit connected to each sensor assembly.

Abstract: The invention relates to a method for determining the running time (t) of an ultrasound flow sensor (6) ultrasound signal (15) which is transmitted by an ultrasound transducer (A, B) to a measuring section (S), wherein the phase position (?F) of said ultrasound signal (15) is determined with respect to a reference clock (8) and a remaining part (r(t)) is determined as a measure of the running time (tmes) of the ultrasound signal (15). The measurement of the running time can be carried out in a particularly robust manner with a minimum use of hardware, when the phase position (?F) is determined with the aid of a quadrature-demodulation method consisting in inverting the received signal (15) in a segmented manner with the aid of a clock signal (8) and the phase of the off-set clock signal (9) and the remaining part (r(t)) is determined according to a characteristic quantity (ts) of the sound signal (15).

Abstract: There is described a method of ultrasonic flow measurement for measuring a flow speed of a fluid in a conduit, the method comprising: providing an ultrasonic flow meter comprising a microprocessor, a clock, and a pair of ultrasonic transducers operable to transmit signals through the fluid and to receive the transmitted signals; switching the ultrasonic flow meter from a passive state to an active state at time intervals measured by the clock, an amount of power used by the ultrasonic flow meter in the passive state being less than an amount of power used by the ultrasonic flow meter in the active state; performing an ultrasonic flow measurement cycle; and switching the ultrasonic flow meter from the active state to the passive state following completion of an ultrasonic flow measurement cycle. There is also described an ultrasonic flow meter for measuring a flow speed of a fluid in a conduit.

Abstract: A method for operating a measuring apparatus (10 for determining the flow rate of a flowable medium through a measuring section (3) is provided, wherein the measuring apparatus (1) has, as sensors, two ultrasonic transceivers (4), which are arranged spaced apart from one another, for the purpose of ultrasonic testing of the measuring section (3) in and counter to the flow direction and for the purpose of picking up signals and is operated with an ultrasonic phase difference method.

Abstract: A clamp-on ultrasonic flow measuring device for determining volume and/or mass flow rate of a medium in a containment. The clamp-on ultrasonic measuring device is of low temperature sensitivity. To this end, the coupling element, through which the ultrasonic measuring signals are coupled into, and/or out of, the containment, has at least two element portions, which are embodied and/or arranged in such a manner that the predetermined in-coupling angle into the containment and/or the predetermined out-coupling angle out of the containment are/is approximately constant over an extended temperature range.

Abstract: A method and apparatus for measuring at least one parameter of a fluid flowing through an internal passage of an elongated body is provided. The internal passage is disposed between a first wall and a second wall, and the first wall and the second wall each include an interior surface and an exterior surface. The method includes the steps of providing an array Of at least two ultrasonic sensor units, operating the sensor units to transmit ultrasonic signals at one or more frequencies substantially coincident with at least one frequency at which the transmitted ultrasonic signals resonate within the first wall, receiving the ultrasonic signals with the sensor units, and processing the received ultrasonic signals to measure the at least one parameter of fluid flow within the internal passage.

Abstract: An ultrasonic flow meter system includes transducers arranged with respect to a conduit to define at least one chordal path through fluid flowing in the conduit, and at least one transmitting transducer and receiving transducer pair on the chordal path for generating a transit time signal. At least one receiving transducer is positioned to receive scattered energy to generate a range gated Doppler signal. The system further includes a processing subsystem for exciting the at least one transmitting transducer. The processing subsystem is responsive to the transit time signal and the range gated Doppler signal and configured to generate a velocity profile and a mean velocity of the fluid in the conduit.

Abstract: A flow rate-measuring apparatus comprises a housing having a passage for supplying a liquid thereto, and a pair of detecting sections provided at both ends of the housing, and which contain sonic wave transmitter/receiver sections capable of transmitting and receiving sonic wave signals. Cover members are installed on each of the detecting sections, wherein the cover members face the passage in the housing. Curved surfaces, which expand toward the passage, are provided respectively on ends of the cover members.

Abstract: An ultrasonic flow rate measuring device, especially a clamp-on ultrasonic flow rate measuring device, with at least one ultrasonic transducer (8) for measuring the flow rate through a line through which a medium flows. The ultrasonic transducer (8) is located within an electromagnetic shielding arrangement (6). Thus, an ultrasonic flow rate measuring device which delivers a good signal-to-noise ratio is achieved.

Abstract: An ultrasonic flowmeter includes two ultrasonic transceivers (10, 16). Each of the ultrasonic transceiver (10, 16) includes a transmitting body (1; 12) fixed to the outer peripheral surface of a measurement pipe (6) through which a fluid to be measured flows so as to surround the measurement pipe (6), and an ultrasonic transducer (2; 13) spaced from the outer peripheral surface of the measurement pipe (6). The transmitting body (1) has axial end surfaces (8a, 8b) perpendicular to the axis of the measurement pipe (6). An axial end surface (7) of the ultrasonic transducer (2) is fixedly secured to the axial end surface (8b) of the transmitting body (1), and the ultrasonic transducer (2) is extended and contracted in the axial direction by applying a voltage between the axial end surfaces (8a, 8b) of the ultrasonic transducer (2).

Abstract: A method for sensing flow within a pipe having an internal passage disposed between a first wall portion and a second wall portion is provided, comprising the steps of: 1) providing a flow meter having at least one ultrasonic sensor unit that includes an ultrasonic transmitter attached to the first wall portion and an ultrasonic receiver attached to the second wall portion and aligned to receive ultrasonic signals transmitted from the transmitter; 2) selectively operating the ultrasonic transmitter to transmit a beam of ultrasonic signal, which beam has a focal point such that within the pipe, the beam is either colliminated, divergent or convergent; and 3) receiving the ultrasonic signals within the beam using the ultrasonic receiver. An apparatus operable to perform the aforesaid method is also provided.

Abstract: An ultrasonic fluid measurement instrument is capable of highly accurate fluid measurement. A measurement part is provided forming a plurality of split channels partitioned by partition boards halfway across a fluid channel, and at least a pair of ultrasonic transmitter-receivers for transmitting ultrasonic waves into the fluid flowing through the split channels and receiving ultrasonic waves that have passed through the fluid. Further, an arithmetic unit calculates the flow velocity and/or flow volume of the fluid according to the propagation time of the ultrasonic waves. The measurement part further includes an approach channel for preliminarily rectifying the fluid flowing to the split channels.

Abstract: An apparatus and method for measuring a flow velocity profile of fluid traveling in a pipe or conduit uses an ultrasonic wave transmitted from an ultrasonic wave transducer mounted at an angle on the outside of a pipe using a wedge, and made incident onto the fluid in the pipe to measure the fluid flow velocity profile, using the principle that a frequency of an ultrasonic wave, reflected by a reflector existing in the fluid, is changed depending on a flow velocity due to Doppler effect. The transmission frequency and the angle of incidence onto the pipe can be selected to suppress frequency dependence of a measured value due to Lamb wave and allow the flow velocity or flow rate of fluid to be measured with a greater accuracy.

Abstract: An ultrasonic flow sensor that includes a conduit having a length, a first ultrasonic transducer disposed at a first position along the length of the conduit, a second ultrasonic transducer disposed at a second position along the length of the conduit, the second position being spaced apart from the first position, a first reflecting interface and a second reflecting interface. The first reflecting interface is in registration with the first ultrasonic transducer to receive first acoustic energy from the first ultrasonic transducer and to reflect the first acoustic energy in a direction generally along a length of the conduit and into a fluid within the conduit. The second reflecting interface is in registration with the second ultrasonic transducer to receive second acoustic energy from the second ultrasonic transducer and to reflect the second acoustic energy in a direction generally along the length of the conduit and into the fluid within the conduit.

Abstract: A tracking system of the present invention includes a transponder 20 attached on a moving object 2 and an autonomous mobile unit 1 for tracking the transponder 20. The autonomous mobile unit 1 has an environment detecting means for acquiring reflection environment information relating to a wall surface 6a, 6b and 6c existing in the vicinity. In this system, the following tracking cycle is executed. The autonomous mobile unit 1 transmits a first ultrasonic wave, and upon receipt of it, the transponder 20 transmits a second ultrasonic wave. By receiving the second ultrasonic wave, the autonomous mobile unit 1 acquires reception information relating to a direct wave that directly arrives at the autonomous mobile unit 1 from the transponder 20 and a reflected wave that arrives via the wall surface.

Abstract: A flowmeter element is used for measuring a mass flow rate of fluid, and includes a semiconductor board, an ultrasonic unit and a pressure detecting unit. The ultrasonic unit performs at least one of sending ultrasonic wave and receiving ultrasonic wave. The pressure detecting unit detects a pressure of the fluid. The ultrasonic unit and the pressure detecting unit are integrally disposed on the semiconductor board.

Abstract: The invention relates to a method for determining blood volume during extracorporeal blood circulation, which is based on measuring the propagation rate or propagation time of the pulse waves propagating in the extracorporeal circulation system. The invention preferably involves the measurement of the propagation rate or propagation time of the pulse waves generated by the blood pump, which is placed in arterial branch of the blood line. The device for determining blood volume can make use of the pressure sensor, which is placed in the venous branch of the blood line and which is already provided in prior art blood treatment devices. As a result, the amount of equipment required is relatively low.

Abstract: The present invention relates to a system and method for measurement of flow velocity using the transmission of a sequence of coherent pulsed ultrasonic signals into the flow, and sampling the received response signal at a predetermined delay time relative to the pulse transmission that does not correspond to the signal transmission time. The sampling may be coherent with a frequency offset from the coherency frequency of the pulses. The received signal samples are then spectrally processed, typically by a Fourier process, to generate a frequency domain data set. A threshold technique is used on the frequency domain data set to determine a peak Doppler shift. Average velocity is then obtained by multiplying the peak Doppler shift by a factor, for example, 0.90. In one embodiment, the transmit pulse and receive samples are interleaved by alternating between transmitting a pulse and, after a delay, sampling the received signal.

Abstract: A transmission measuring system includes a subject for transmission measurement for outputting, in response to a start signal for measurement from a central processing unit, an output signal including information on a transmission time to be measured. An analog-digital converter converts the output signal into digital data. The central processing unit processes the digital data to obtain the transmission time required for propagating the signal through the subject. A clock signal source provides a clock signal to the central processing unit, and a variable delay unit is interposed between the clock signal source and the analog-digital converter. The central processing unit delivers a delay time control signal to the variable delay unit so that the delay time of the clock signal of the analog-digital converter may be varied with time relative to the start signal for measurement.

Abstract: A flow measuring system is provided that provides at least one of a compensated mass flow rate measurement and a compensated density measurement. The flow measuring system includes a gas volume fraction meter in combination with a coriolis meter. The GVF meter measures acoustic pressures propagating through the fluids to measure the speed of sound ?mix propagating through the fluid to calculate at least gas volume fraction of the fluid and/or the reduced natural frequency. For determining an improved density for the coriolis meter, the calculated gas volume fraction and/or reduced frequency is provided to a processing unit. The improved density is determined using analytically derived or empirically derived density calibration models (or formulas derived therefore), which is a function of the measured natural frequency and at least one of the determined GVF, reduced frequency and speed of sound, or any combination thereof.

Abstract: In an ultrasonic flow meter for measuring a flow rate of a fluid flowing through a conduit by detecting a propagating time difference between a forward propagating time of an ultrasonic wave propagating within the conduit in a forward direction and a backward propagating time of an ultrasonic wave propagating within the conduit in a backward direction, forward and backward ultrasonic wave signals generated by ultrasonic vibrating elements are sampled to derive forward and backward digital data series x and y, which are stored in a memory, the forward and backward digital data series x and y are read out of the first and second memory units and total sums of absolute difference values between the forward and backward digital data series x and y are calculated, while data positions of these backward and forward digital data series x and y are relatively shifted, a shift amount of data positions at which a total sum of absolute difference values becomes minimum is detected, an ultrasonic propagating time differe

Abstract: An ultrasonic flowmeter casts an ultrasonic pulse toward a measurement line ML, processes ultrasonic echo signals, and calculates the position and speed of each ultrasonic reflector positioned along the measurement line ML by analyzing the ultrasonic echo signals subjected to signal processing. The flowmeter filters the ultrasonic echo signals. A trigger oscillator of the flowmeter controls signal transmission/reception timing according to an adjustable sequence wherein one cycle is formed of three consecutive sets of emissions of an ultrasonic pulse and reception of ultrasonic echo signals, and a waiting period of time.

Abstract: An elastomeric acoustic coupler formed by molding a thermoplastic or silicone rubber into a recess of a surgical cassette housing. The coupling has a raised pad to aid in the removal of all air between the transducer and the fluid conduit, and to provide an efficient transmission of an ultrasound signal into the fluid conduit.

Abstract: A flow rate-measuring apparatus comprises a housing having a passage for supplying a liquid thereto, and a pair of detecting sections provided at both ends of the housing, and which contain sonic wave transmitter/receiver sections capable of transmitting and receiving sonic wave signals. Cover members are installed on each of the detecting sections, wherein the cover members face the passage in the housing. Curved surfaces, which expand toward the passage, are provided respectively on ends of the cover members.

Abstract: An ultrasonic signal processing method for improving the signal-to-noise ratio in ultrasonic measurements comprises the transmission of a predefined timed sequence of a number of ultrasonic burst signals at a first transducer, and reception of a signal representing said transmitted sequence of ultrasonic burst signals at a second transducer. This signal is processed by addition of multiple time-shifted copies of the received signal to said original received signal to obtain a sum of the original received signal and its time-shifted copies. An original burst signal having an improved signal-to-noise ratio is reconstructed from this sum.

Abstract: A transmitting and receiving circuitry system for an ultrasonic flowmeter includes an ultrasound transducer interface for connection to an ultrasound transducer of the ultrasonic flowmeter, an amplifier with a first input and a second input, as well as a signal generator for activating the ultrasound transducer, with the first input of the amplifier connecting to the signal generator while the second input of the amplifier connects both to the ultrasound transducer interface and, via a feedback element, to the output of the amplifier. The impedance of the feedback element can be varied, permitting an adaptation of the transmitting and receiving circuitry to the operating mode of the ultrasonic flowmeter, in particular an adaptation to a transmitting or receiving mode, whereby an overall improvement of the signal-to-noise ratio is attainable. A method for operating such a system is also disclosed.

Abstract: An ultrasonic fluid measurement instrument is capable of highly accurate fluid measurement. A measurement part is provided forming a plurality of split channels partitioned by partition boards halfway across a fluid channel, and at least a pair of ultrasonic transmitter-receivers for transmitting ultrasonic waves into the fluid flowing through the split channels and receiving ultrasonic waves that have passed through the fluid. Further, an arithmetic unit calculates the flow velocity and/or flow volume of the fluid according to the propagation time of the ultrasonic waves. The measurement part further includes an approach channel for preliminarily rectifying the fluid flowing to the split channels.

Abstract: An ultrasonic apparatus measures the concentration and flow rate of a sample gas by calculating a possible propagation time range on the basis of the gas temperature, determining whether or not the phases at which two first trigger signals, respectively generated on the basis of forward and backward waveforms of the ultrasonic waves, coincide with each other, processing the zero-cross signals so that the phases coincide with each other, obtaining reference zero-cross time instant by calculating mean value of the forward and backward zero-cross time instants, obtaining an ultrasonic reception point by subtracting an integral multiple of the cycle of the ultrasonic waves so that the results of the subtraction falls into a possible propagation time range and estimating the ultrasonic propagation time on the basis of the ultrasonic reception point.

Abstract: A fluid flow sensor uses pairs of acoustic transducers to generate quasi-helical acoustic beams reflected multiple times from an inside surface of a pipe. The transducers are arranged so that each two pairs generate counter-rotating beams. When fluid flowing in the pipe has both a rotary and an axial flow component the rotary component adds to the apparent flow rate measured in one rotational direction and subtracts from that measured in the other. Hence, a combination of transit time measurements along the two paths can be used to cancel out the effects of the rotary flow component and yield a measure of the rate of flow along the pipe axis. In some cases multiple probes are used to increase the amount of flowing fluid that is sampled.

Abstract: The present invention relates to an apparatus and method for improved check valve technology used in flow meters, particularly compound/combo meters. The improved check valve technology may be comprised in a single piece module that (1) can easily be removed from the meter without disturbing the metering module, (2) has few or no complicated rollers and pins that require calibration, (3) requires little or no special training to remove, (4) does not require the meter repairperson to move relatively heavy objects, (5) comprises a seal as part of the check valve assembly simplifying seal inspection, seal removal and seal replacement; and (6) is secured in its housing using only external fasteners. The check valve module may be used for upgrading meters installed at customer sites, for upgrading used meters returned for repairs, and for simplifying new meter production.

Abstract: A device for measuring flow in a pipe includes a first metal plate mounted to the pipe, the first metal plate including a first contact portion contacting a wall of the pipe and a first away portion spaced apart from the wall of the pipe, a second metal plate mounted to the pipe, the second metal plate including a second contact portion contacting the wall of the pipe and a second away portion spaced apart from the wall of the pipe, a first transducer mounted to the first away portion, and a second transducer mounted to the second away portion.

Abstract: An apparatus for determining the flow rate of a fluid in a pipe. The apparatus includes a device for providing acoustic energy on a diametrical path through the fluid. The diametrical providing device is in contact with the pipe. The apparatus also includes a signal processing device for determining the speed of sound of the fluid in the pipe based on the acoustic energy of the diagonal providing device and the acoustic energy of the diametrical providing device. A method for determining the sound velocity of a fluid in a pipe.

Abstract: Methods and related systems for determining transducer delay time and transducer separation in ultrasonic flow meters. At least some of the illustrative embodiments are a method comprising measuring a delay time for a first transducer pair, measuring a total measured time for ultrasonic signals transmitted between a second transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed, calculating a parameter associated with the second transducer pair using the delay time of the first transducer pair and the total measured time for said second transducer pair.

Abstract: An automated method and system for calculating the transit time of a pulsed signal transmitted from a first ultrasonic transducer to a second ultrasonic transducer is provided. The method includes measuring the amplitude of the pulsed signal received at the second transducer from the first transducer; measuring the amplitude of any noise proximate to the received pulsed signal; and calculating the signal to noise ratio of the received pulsed signal and the noise, respectively. If the signal to noise ratio is above a predetermined threshold, a first technique is automatically implemented for calculating the transit time of the received pulsed signal. If the signal to noise ratio is less than the predetermined threshold, a second different technique is automatically implemented for calculating the transit time of the received pulsed signal.

Abstract: An ultrasonic gas flowmeter includes a measuring pipe with flowing gas, transmitting and receiving sound transducers, transmission and reception electronics, and evaluation electronics. The sound transducers (7, 8, 9, 10) are designed as capacitive electro-acoustic ultrasonic transducers to construct a flowmeter with improved capacity, especially in view of temperature stability and the reduction and consideration of a temperature profile. Devices (5, 6) are provided to level the gas temperature profile and to minimize the influence of the temperature profile on the flow measurement. A more accurate and dependable detection of the volume flow or the mass flow of gases is to be achieved, especially in highly dynamic flows, for the method of determining the flow of gases whereby the mean flow velocity is determined and the flowing gas quantity is determined with highly synchronized resolution from the two transit times of two acoustic signals.

Abstract: An ultrasonic flowmeter includes a transmission/reception means provided in a flow path for performing transmission/reception using a state change of fluid; repetition means for repeating the transmission/reception; time measurement means for measuring a time of propagation repeated by the repetition means; flow rate detection means for detecting a flow rate based on a value of the time measurement means; and number-of-times change means for changing to a predetermined number of repetition times. With such a structure, an influence caused by a variation of a flow can be suppressed by changing the number of repetition times so as to be suitable for a variation. As a result, reliable flow rate measurement with a high accuracy can be achieved.

Abstract: A method and apparatus for remote laser-based detection of gas at levels exceeding natural background levels preferably utilizing wavelength modulated tunable diode laser absorption spectroscopy. In a preferred embodiment, background gas and noise are estimated using statistical moving average and variance calculations. Gas concentration length measurements resulting from the spectroscopy are preferably compared in real-time or near-real-time to the sum of the background and noise estimates and an alarm limit to detect gas presence of concern. Gas levels exceeding this detection threshold are preferably indicated by a prolonged output tone with a pitch indicative of the magnitude of the gas measurement, and gas levels below the detection threshold are preferably indicated by silence.