Fluid flow meter

A system comprising:

• a flow meter having a housing that defines a chamber having a fluid inlet and a fluid outlet and having a first gear and a second gear installed within the chamber, the first gear intermeshing with the second gear so that the first gear and the second gear rotate together in response to fluid flow through the chamber, and at least one of the first gear and the second gear having a detectable area for detecting a rotational position of the first gear and the second gear;
• a first non-contact sensor configured to generate a first detection signal and to sense the detectable area when the first gear and second gear are in a first range of rotational positions, the first detection signal indicative of a position of the detectable area relative to the first non-contact sensor;
• a second non-contact sensor configured to generate a second detection signal and to sense the detectable area when the first gear and second gear are in a second range of rotational positions, the first and second ranges of rotational positions being different, the second detection signal indicative of a position of the detectable area relative to the second non-contact sensor;
• and
• a controller operatively connected to the first non-contact sensor and the second non-contact sensor and configured to:
• receive the first detection signal;
• receive the second detection signal;
• based on the first detection signal and the second detection signal, determine which rotation state from a plurality of rotation states the detection signals currently correspond to and defining such rotation state as the current rotation state, the plurality of rotation states having a pre-defined sequential order, defined as a sequence of rotation states, and corresponding to a sequence of rotational positions of the first and second gears in response to fluid flow through the chamber;
• increment a rotational count indicative of a number of rotations of the first and second gears when the current rotation state changes, in order, through the sequence of rotation states.