An inertia force or Coriolis force mass flowmeter comprises a pair of conduits having a substantially identical configuration disposed in a parallel and superimposing relationship with a space therebetween and flexurally vibrated relative to one another; wherein each of the pair of conduits has two end sections disposed at a close proximity to one another in a side-by-side relationship and secured to a common region of a supporting structure, and a curved midsection of a loop angle approximately equal to 360 degrees connecting the two end sections of the conduit to one another, which inertia force or Coriolis force mass flowmeter determines mass flow rate of media moving through at least one of the pair of conduits as a function of a phrase angle difference between two alternating electrical signals representing the relative flexural vibration between the pair of conduits respectively at two different sections of the combination of the pair of conduits.