Abstract: A meter includes a casing (1) with a fluid passage (2), in which two transducer mountings (3, 4) arranged at a distance (Lb) from each other support two transducers (5, 6) which are acoustically opposed to each other. Between the transducers (5, 6) there is a distance (Lu) over which they transmit and receive sound pulses through a fluid which in a direction (a) flows through the fluid passage (2). On the basis of the transit times of the sound pulses over the distance (Lu) both countercurrently with and countercurrently to the direction of flow (a), e.g. the velocity of the flow of the fluid is then calculated. A compensating device (8, 9) is arranged between at least one of the transducers (5, 6) and one of the transducer mounts (3, 4).

Abstract: A tube/casting assembly and method according to which an axially-projecting cylindrical flange projects from one end of a tubular casting over which an end portion of the conduit extends. A groove is formed in the casting for receiving the end portion and a retainer secures the end portion of the conduit in the groove.

Abstract: In flow measurement, a measurement signal essentially representing the instantaneous flow rate is determined with the aid of a flow transducer (2) in a flowmeter (1). In order to check whether the flowmeter measures correctly or not, the noise in the measurement signal from the transducer (2) is analyzed. To be more specific, one or more distribution values for the measurement signal are determined and compared with predetermined reference values that have been determined for operating conditions for which the flow transducer is intended. If this comparison reveals that the existing operating conditions differ from those for which the flowmeter is intended, a frequency spectrum for the measurement signal may be determined and compared with reference spectra that have been determined for various known operating conditions, thereby to identify the existing operating conditions. If these are identified, the function of the flowmeter may be corrected on line with the aid of predetermined correction data.

Abstract: During sing-around-type measurement in a fluid, a transmitter repeatedly transmits sound pulses in the fluid, and these sound pulses are received by a receiver, which acoustically is disposed opposite to the transmitter. The detection of the reception of a sound pulse at the receiver triggers the transmission of a subsequent sound pulse by the transmitter. In order to avoid any interference from multiple-reflected sound pulses, a delay is produced with the aid of the frequency of the received sound pulse, and the transmission of the subsequent sound pulse by the transmitter is triggered with this delay.

Abstract: In a method for measuring the mass flow M of a fluid flowing through a pipe having a cross-sectional area A, the sound velocity c.sub.2 in the fluid is determined as well as the flow velocity v of the fluid by sing-around technique. Further, reflection technique is used which comprises measuring the amplitude both of an ultrasonic pulse which has been reflected in a boundary between a first and a second material having different acoustic impedances, and of an ultrasonic pulse which has been reflected in the boundary between the second material and the fluid, it being possible to determine the density of the fluid on the basis of the measured amplitudes, the sound velocity c.sub.2 in the fluid and the acoustic impedances of the first and the second material. The mass flow M is then obtainable as M=v.times.A.times..rho..sub.2.