Apparatus for measuring liquid flow

Claim 1

In a measurement generator for determining the rate of flow of a fluid passing through a pipe system, said pipe system including a housing and a test tube of a predetermined length disposed within said housing, said test tube extending along a longitudinal direction, the fluid flow being determined by measuring the transit time of ultrasound pulses within the fluid flowing through said test tube, a sound pulse emitting transducer being disposed near one end of said test tube in a first distribution chamber, said sound pulse emitting transducer having a first sound-transfer area, a sound-pulse receiving transmitter being disposed near the other end of said test tube in a second distribution chamber, said sound-pulse receiving transducer having a second sound transfer area, at least one distribution chamber forming part of said housing, said test tube including metallic material having a cross-section remaining the same over the entire length of said test tube, a common divider wall having an opening and separating said distribution chambers from one another, said test tube passing through said opening, said transducers being disposed at a certain distance from the respective test tube ends, said test tube guiding the ultrasound pulses from said sound transfer area of said sound-pulse emitting transducer to said sound transfer area of said sound-pulse receiving transducer along an axis coinciding with the flow of said test tube, the improvement comprising non-metallic connecting means extending along and surrounding said test tube so as to connect portions near opposite ends thereof through said opening in said common dividing wall, said common dividing wall extending approximately at right angles to said longitudinal direction, whereby any sound echoes bouncing off said common divided wall are reduced in intensity.