A method of operating an acoustic resonance fluid flow sensor. The method comprises emitting an acoustic stimulus signal comprising a plurality of frequencies into an acoustic resonance cavity of the acoustic resonance fluid flow sensor, sensing an acoustic response signal within the acoustic resonance cavity and deriving the phases or equivalent group delays of one or more frequency components of a frequency spectrum of the acoustic response signal.

Passive wireless sensors include an antenna. The antenna receives a combined signal. The combined signal includes a low frequency modulating signal modulated on a high frequency carrier wave. A demodulator receives the combined signal and extracts the modulating signal. A sensor receives the extracted modulating signal and produces an output signal with a time delay indicative of a property to be sensed. A modulator receives the output signal and the high frequency carrier wave and modulates the output signal onto the high frequency carrier wave to create a combined output signal broadcast by the antenna.

Methods, systems, and apparatuses are provided for detecting and determining conditions of and conditions within a fluid conduit.

A flow meter for calculating fluid flow rate and/or volume includes a flow cell shaped to define an internal passageway through which the fluid travels, and four separate transducer assemblies independently mounted within mounts in the flow cell in fluid communication with the internal passageway. Each transducer assembly includes a transducer, a transducer stud with a recess in its front surface that is dimensioned to receive the transducer, and a sensor plate mounted onto the stud for retaining the transducer in the recess. A bore extends vertically through the transducer stud and into communication with the recess, the bore being dimensioned to receive wiring for the transducer. The separation and independent mounting of the four transducer assemblies in the flow cell minimizes the disruption of normal fluid flow through the internal passageway, thereby enabling greater accuracy of measurements to be achieved.

Described are an apparatus, computer program product, and associated methods for shaped waveform acoustic interrogation of substances and materials to determine one or more properties of the materials or substances. In some embodiments, a shaped waveform is formed by summing two or more different waveforms and an acoustic wave is generated according to the shaped waveform. The acoustic wave is transmitted by one or more transmitting transducers through the substance or material and received by one or more receiving transducers. The shaped waveform acoustic wave can have a duration or a period that is less than about 20 μs and can comprise predetermined frequency content. Characteristics of the shaped waveform acoustic wave, as received at the receiving transducer(s), including characteristics such as amplitude, frequency, time of flight, etc., can be associated with said one or more properties of the substance or material to provide for real-time monitoring of these properties.

An ultrasonic flowmeter includes first and second ultrasonic transducers and a control and evaluation unit connected thereto. The first and/or second ultrasonic transducer is/are an ultrasonic transmitter and/or an ultrasonic receiver. The first and second ultrasonic transducers are arranged on a measuring tube in such a way that a signal path is formed therebetween, and such that a measuring signal emitted by the ultrasonic transmitter runs via the signal path to the ultrasonic receiver. The first and/or second ultrasonic transducer has array to of at least two active elements. At least one ultrasonic transducer with an array of at least two active elements is formed as a wedge transducer. At least two active elements of the array arranged on the first ultrasonic transducer, and/or at least two active elements of the array arranged on the second ultrasonic transducer, are separately controllable by the control and evaluation unit.

In one embodiment, an electronic system comprises a display device to display data and processing logic coupled to the display device. The processing logic is configured to determine a duty cycle of at least one sensor for sensing flow of a product or particle through a product or particle line of an agricultural implement and to determine an amount of product or particles flowing through a line of the agricultural implement based on the duty cycle of the at least one sensor.

A clamp-on ultrasonic flowmeter includes pairs of ultrasonic transducers arranged on an exterior of a pipeline, and an electronic measuring/operating circuit for operating the transducers and for registering and evaluating measurement signals and for providing measured values of volume flow or flow velocity. The pairs are implemented as 1-traverse or 2-traverse pairs. One-traverse pairs are arranged on opposite sides of the pipeline, and 2-traverse pairs are arranged on a same side of the pipeline. At least three pairs are arranged on the pipeline and are distributed peripherally. Adjoining pairs of a number of pairs have an inner angle down to a minimum inner angle (MIA) between one another measured about a pipeline axis, which minimum inner angle obeys the following relationship:

MIA=360°/(T*N*F(T,N))

with T as number of traverses and F(T,N)=0.38+0.62*T+(0.048−0.01*T{circumflex over ( )}2)*(N−2){circumflex over ( )}2.

Flow meters are disclosed that provide improved measurements of fluid flowing through fan coils. A flow meter includes a body that defines an inlet, an outlet, and a flow path extending along a longitudinal axis between the inlet and the outlet. The flow meter also includes transducers coupled to the body and exposed to the flow path defined by the body. The transducers are configured to transmit and receive a signal travelling through the flow path to measure a flow rate of fluid of the fan coil. The flow meter also includes one or more reflectors coupled to the body and exposed to the flow path defined by the body. Each of the one or more reflectors has a flat reflective surface that is exposed to the flow path and is configured to reflect the signal to relay the signal between the transducers.

A modular ultrasonic flow meter including a substantially watertight meter housing connected to a flow tube; a measurement printed circuit board including a measurement circuit communicating with one or more ultrasonic transducers, arranged in the meter housing for transmitting and receiving ultrasonic signals; and a self-contained power supply. The ultrasonic flow meter further includes a control module comprising a module housing connected with a main printed circuit board including a central processing unit, a memory circuit and a communication circuit, and a power- and communication connection is provided between the main printed circuit board of the control module and the measurement printed circuit board whereby the self-contained power supply may power the main printed circuit board and the measurement printed circuit board.