An acoustic band-pass filter assembly includes an inlet, a microphone configured to receive acoustic energy from the inlet, and a plurality of resonator chambers disposed in series between the inlet and the microphone and configured to transmit acoustic energy between the inlet and the microphone. Each of the plurality of resonator chambers has a different cross-sectional area.

The disclosure relates to a breathing tube arrangement for a lung function diagnostics device, comprising a breathing tube defining a guiding path for breathing air to be analyzed by a lung function diagnostics device, the breathing tube having a proximal end, a distal end and an analysis zone located between the proximal end and the distal end. According to an aspect of the disclosure, the breathing tube arrangement comprises a filter element having a filter material, a breathing air releasing region arranged distally of the filter material, and a diffusor zone arranged proximally of the filter material, wherein the diffusor zone comprises a proximal end having a first proximal cross-sectional area and a distal end having a first distal cross-sectional area that is bigger than the first proximal cross-sectional area, and wherein the breathing air releasing region has a second distal cross-sectional area, wherein the second distal cross-sectional area is bigger than the first proximal cross-sectional area and at least as big as the first distal cross-sectional area, wherein a ratio between the first proximal cross-sectional area and the second distal cross-sectional area lies in a range of between 1:2 to 1:20.

A device, a method, and a non-transitory storage medium are described in which a transducer validation service is provided. The service may include stimulating a piezoelectric transducer. The service may include measuring a signal output, which is responsive to the stimulus, from the piezoelectric transducer. The service may include evaluating the measured signal output to a reference voltage and determining whether the piezoelectric transducer is reverse-poled or not based on the evaluation. The service may further include determining a response to the determination when the piezoelectric transducer is reverse-poled.

A consumption meter arranged to measure a flow rate of a fluid comprising: a tube with two transducer holes in a wall of the tube; a meter housing arranged at the tube, comprising two transducer housings and a main housing; first and second ultrasonic transducers arranged in the transducer housings for transmitting and receiving ultrasonic signals propagating through the fluid; a control circuit arranged in the meter housing for operating the first and second ultrasonic transducers to generate a signal according to the flow rate of the fluid. The transducer housing comprises: an internal transducer housing element arranged at an inner surface of the tube and an external transducer housing element arranged at an outer surface of the tube to extend through the transducer hole in the wall of the tube such that the transducer housing is fixated to the tube.

A method for acoustic leakage detection in a fluid pipe network (1) uses at least one ultrasonic flow meter (13) installed at a pipe (15, 17). The pipe connects a consumer site (3) to the fluid pipe network. The method includes detecting at least one sound wave traveling along the pipe and/or along fluid within the pipe from a sound source to the at least one ultrasonic flow meter, determining the traveling direction of at least one of the at least one sound wave, interpreting a sound wave of the at least one sound wave as a leakage sound candidate if the determined traveling direction of said sound wave is towards the consumer site, and interpreting a sound wave of the at least one sound wave as a background noise if the determined traveling direction of said sound wave is away from the consumer site.

An ultrasonic flowmeter having a measuring tube, a control unit, at least one first ultrasonic measuring unit and a second ultrasonic measuring unit, the measuring tube having a measuring tube interior and a measuring tube longitudinal axis, wherein each of the ultrasonic measuring units is arranged on the measuring tube, wherein each ultrasonic measuring unit has a first ultrasonic transducer and a second ultrasonic transducer, the first and the second ultrasonic transducers spanning a sound measuring section with a sound axis. The sound measuring section and the sound axis penetrate the measuring tube interior for carrying out ultrasonic measurements. To provide an ultrasonic flowmeter for reliable measurement of a multi-phase medium, the sound axis of the first ultrasonic measuring unit and the sound axis of the second ultrasonic measuring unit span a sound measuring plane which extends substantially parallel to the longitudinal axis of the measuring tube.

A soft-melted parison is disposed in molds forming a shape of a measurement pipeline portion 10, the parison is expanded by means of gas inflow, and blow molding is performed. The shapes of a pipe body 11, a fluid inlet portion 12, and a fluid outlet portion 13 are formed by an inner mold of the molds. Ultrasonic wave input-output portions 14a and 14b bulging outwards in a sealed manner are formed on both sides positioned in the oblique direction of the pipe body 11 with respect to a center line of the pipe body 11. Parts of the ultrasonic wave input-output portions 14a and 14b are wall surfaces 15a and 15b for attaching ultrasonic wave transmission-reception units. The measurement pipeline portion 10 is obtained by cutting end portions of the fluid inlet portion 12 and the fluid outlet portion 13 after the parison is solidified.

A gas safety device includes: flow path through which a gas flows; ultrasonic sensor for measuring a flow rate of the gas flowing through flow path; flow rate calculator that calculates a flow rate measurement data pieces from a measurement value of the flow rate measured by ultrasonic sensor; and leakage detector that detects a minor leakage of the gas. The gas safety device further includes: pulsation recognizer that recognizes that pulsation is occurring when a fluctuation in the flow rate measuring data pieces calculated by flow rate calculator is greater than or equal to a predetermined value; and pulsating flow rate corrector that corrects, when pulsation recognizer determines that the pulsation is occurring, the flow rate measurement data piece by a predetermined value. Furthermore, when pulsation recognizer determines that the pulsation is occurring, leakage detector determines whether a leakage is present using the flow rate measurement data piece corrected by pulsating flow rate corrector.

A system includes a transducer assembly for a flowmeter. The transducer assembly includes a housing with a front face and at least one attenuating rib. The transducer assembly also includes a transducer positioned in the housing and configured to direct an emitted acoustic signal through the front face of the housing and into a flow path of the flowmeter and to receive a received acoustic signal through the front face of the housing. The system also includes a controller configured to use the received acoustic signal to determine a ratio of a first component versus a second component in a gas flowing through the flow path of the flowmeter.

An electronic device may include air input sensors that gather air input from a user's fingers, a stylus, or other object in a volume of air near the electronic device. The air input sensors may include ultrasonic transducers that emit ultrasonic signals towards the volume of air and that detect the ultrasonic signals after the signals reflect from the external object. Using time-of-flight measurement techniques, control circuitry may track the movement of the external object in the volume of air near the electronic device. A display may provide visual feedback of the air input, such as shadows that preview where the input will be directed to on the display. The volume of air where input is detected may be divided into multiple input zones that trigger different actions from the electronic device. The ultrasonic transducers may include acoustic lenses.