Abstract: A rotameter system adapted to produce an output indication that is linearly proportional to flow. The primary element of the system includes a float contained in a variable area tube through which flows the fluid to be measured, the float being raised or lowered in the tube as a function of flow rate, and a bar magnet mechanically coupled to the float and axially movable therewith. The secondary element of the system includes a rotatable follower magnet magnetically coupled to the bar magnet and a pointer mounted on the shaft of the follower magnet whereby the pointer sweeps from zero to maximum along a scale as the float travels from its low to its high position. A mass is eccentrically mounted on the shaft of the follower magnet, the position of the mass relative to the shaft axis being adjusted to produce a moment compensating for the non-linear relationship between flow rate and pointer movement.