Patent ID: 7963175

Claim:
An apparatus for measuring one or more characteristics of a fluid flowing within a pipe, which pipe has a pipe wall and an exterior surface, the apparatus comprising: a housing operable to be mounted on the exterior surface of the pipe, which housing has at least one pocket extending between a pipe-side surface and an outer surface, wherein the pipe-side surface mates with the exterior surface of the pipe; an acoustic couplant disposed within the at least one pocket, between each sensor unit and the exterior surface of the pipe; a sealant disposed between the exterior surface of the pipe and the pipe-side surface of the housing, which sealant forms a seal around the pocket when the housing is mounted on the exterior surface of the pipe, which seal is operable to prevent acoustic couplant leakage from inside the housing to outside the housing; and an array of at least two ultrasonic sensor units for transmitting ultrasonic signals through the fluid flow within the pipe and a receiver for receiving such signals, which array is disposed within the at least one pocket.