Abstract: The disclosure relates to determination of a flow rate of a fluid flowing through a conduit, whilst compensating for conduit-borne interference. Transducers are used to emit ultrasonic signals into the fluid and receive the signal after propagating through a section of the conduit. Waves that have propagated through the fluid are detected and noise from pipe-borne interference is removed via signal processing.

Abstract: A transit time flow meter apparatus for determining a flow rate of a flowing fluid using a time difference between upstream and downstream acoustic transmissions in the fluid, the flow meter including a pair of segmented transducers to be arranged in spaced relation on a flow tube, wherein respective ones of the segmented transducers include at least two portions, wherein at least one of the two portions is an active transducer portion separated from the or each other portion by one of an expansion gap or gaps, or a deformable element, whereby to enable fluctuations in a flow tube dimension to be accommodated without damage being caused to the active transducer portion.

Abstract: A transit time flow meter apparatus for determining a flow rate of a flowing fluid using a time difference between upstream and downstream acoustic transmissions in the fluid, the flow meter including a pair of segmented transducers to be arranged in spaced relation on a flow tube, wherein respective ones of the segmented transducers include at least two portions, wherein at least one of the two portions is an active transducer portion separated from the or each other portion by one of an expansion gap or gaps, or a deformable element, whereby to enable fluctuations in a flow tube dimension to be accommodated without damage being caused to the active transducer portion.

Abstract: A transit time differential acoustic flowmeter having acoustic transducers which are acoustically coupled to the fluid flowing in a flow tube through the wall of the flow tube itself, in which the flow tube is demountable from the flowmeter and can be disconnected from the external circuit delivering and carrying away the fluid the flow of which is to be detected.

Abstract: An acoustic flowmeter comprising a flow tube including an inner elongate member in the flow tube to define at least one flow passage for the flowmeter.

Abstract: A transit time differential acoustic flowmeter having acoustic transducers which are acoustically coupled to the fluid flowing in a flow tube through the wall of the flow tube itself, in which the flow tube is demountable from the flowmeter and can be disconnected from the external circuit delivering and carrying away the fluid the flow of which is to be detected.

Abstract: An acoustic flowmeter comprising a flow tube including an inner elongate member in the flow tube to define at least one flow passage for the flowmeter.