Abstract: A mass flowmeter of the Coriolis-type in which fluid to be metered is conducted through a flow tube which is coiled to define a helix having a pair of identical measuring loops forming a double loop, on either side of which is an isolation loop. The fluid is admitted into the input of one isolation loop and is discharged from the output of the other isolation loop. The helix is concentric with a support structure having at one end a flow inlet to which the isolation loop input is affixed, and at the other end a flow outlet to which the isolation loop output is attached. A rigid bar parallel to the axis of the helix is joined to the junction of the measuring loops as well as to the respective junctions of each measuring loop and its associated isolation loop whereby the isolation loops then function as decoupling springs to effectively isolate the bar and the double measuring loop from external forces.