Abstract: A mass flow meter for fluids flowing through a conduit wherein the fluid passes through an axial flow driving impeller. A balancing impeller attached to the driving impeller by a shaft rotates in a damping fluid provides a linear torque versus rotational speed relationship. By providing a resistance torque subject to cause the driving impeller to rotate very slowly, the rate of rotation of the shaft becomes proportional to mass flow rate. According to another aspect of the invention, a float submersed within the damping fluid is attached to the shaft whereby an upward acting weight counterbalancing force is exerted. A second embodiment is disclosed including two driving impellers which provides protection for the meter from transient loads exerted by the measured fluid.